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1
Tecchio, Marco Antonio, SARITA LEONEL, LUIS LESSI DOS REIS, LILIAN MASSARO SIMONETTI, and MARLON JOCIMAR RODRIGUES DA SILVA. "STIMULATE NO DESENVOLVIMENTO DE MUDAS DE KUNQUAT ‘NAGAMI’." IRRIGA 1, no. 1 (2015): 97–106. http://dx.doi.org/10.15809/irriga.2015v1n1p97.
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STIMULATE NO DESENVOLVIMENTO DE MUDAS DE KUNQUAT ‘NAGAMI’ MARCO ANTONIO TECCHIO1; SARITA LEONEL1; LUIS LESSI DOS REIS2; LILIAN MASSARO SIMONETTI2 E MARLON JOCIMAR RODRIGUES DA SILVA2 1 Eng. Agr., Doutor, Departamento de Horticultura, Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Faculdade de Ciências Agronômicas, Botucatu – SP, Caixa Postal 237. CEP: 18.610-307. E-mail: tecchio@fca.unesp.br; sarinel@fca.unesp.br.2 Eng. Agr., estudantes de pós-graduação, Departamento de Horticultura, Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Faculdade de Ciências Agronômicas, Botucatu – SP, Caixa Postal 237. CEP: 18.610-307. E-mail: lessireis@fca.unesp.br; lilian_simonetti@hotmail.com; marlonjocimar@gmail.com 1 RESUMO Objetivou-se avaliar o efeito do Stimulate® no crescimento de mudas de Kunquat ‘Nagami’, em condições de casa de vegetação, do Departamento de Horticultura da Faculdade de Ciências Agronômicas, UNESP. As mudas de Kunquat ‘Nagami’ (Fortunella sp.), enxertadas sobre Limoeiro ‘Cravo’ (Citrus limonia Osbeck) foram adquiridas de um viveiro comercial de citros, localizado no município de Jacuba-SP, com 30 dias após a enxertia. Aos 60 dias após a enxertia, quando as mudas de Kunquat ‘Nagami’ atingiriam altura média de 40 cm e 22 folhas, foram realizadas quatro aplicações do bioestimulante Stimulate® nas seguintes concentrações: 0, 50, 100, 150 e 200 mL L -1 de solução. Realizaram-se avaliações no crescimento das mudas aos 7, 14 e 21 dias após a última aplicação de Stimulate®. Avaliaram-se as variáveis: altura da planta, número de folhas, massa fresca e seca da parte aérea, massa fresca e seca da raiz, comprimento da raiz principal, diâmetro do caule do porta-enxerto e do caule da copa, área foliar e o índice relativo de clorofila. Obteve-se, com a dose de 200 mL de Stimulate® L-1, aumento na altura da planta, no número de folhas, no comprimento da raiz e no diâmetro da copa das mudas de Kunquat ‘Nagami’. Palavras chaves: Fortunella sp, viveiro, reguladores vegetais TECCHIO, M. A.; LEONEL, S.; REIS, L. L.; SIMONETTI, L. M., SILVA, M. J. R.EFFECT OF STIMULATE ® ON GROWTH OF ‘NAGAMI’ KUNQUAT SEEDLINGS 2 ABSTRACT The objective of this study was to evaluate the effect of Stimulate® on growth of ‘Nagami’ Kunquat seedlings in a greenhouse at the Horticulture Department in the College of Agricultural Sciences, UNESP. The seedlings of ‘Nagami’ Kunquat (Fortunella sp) grafted onto ‘Rangpur’ lime (Citrus limonia Osbeck) were from a commercial seedling nursery of citrus in Jacuba city-SP and were at 30 days after grafting. At 60 days after grafting, when the seedlings reached 40 cm mean height and 22 leaves, a total of four applications of Stimulate® plant growth regulator were performed in the following concentrations: 0, 50, 100, 150 and 200 mL L -1 of solution. Seedling growth evaluations were performed at 7, 14 and 21 days after the last Stimulate® application. The following variables were evaluated: plant height, number of leaves, above ground fresh and dry matter, fresh and dry matter of roots, length of roots, diameter of the rootstock and canopy stems, leaf area and the relative chlorophyll index. The application of 200 mL Stimulate® L-1 in ‘Nagami’ Kunquat seedlings led to an increase in plant height, number of leaves, root length and stem diameter of canopies. Keywords: Fortunella sp, seedling nursery, plant growth regulator
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TECCHIO, MARCO ANTONIO, TATIANA PIRES DE ALMEIDA MERLIM, SARITA LEONEL, and HÉLIO GRASSI FILHO. "APLICAÇÃO DE COBRE EM MUDAS CÍTRICAS." IRRIGA 1, no. 1 (2015): 87–96. http://dx.doi.org/10.15809/irriga.2015v1n1p87.
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APLICAÇÃO DE COBRE EM MUDAS CÍTRICAS MARCO ANTONIO TECCHIO1; TATIANA PIRES DE ALMEIDA MERLIM2; SARITA LEONEL1 E HÉLIO GRASSI FILHO3 1 Eng. Agrônomo, Doutor, Departamento de Horticultura, Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Faculdade de Ciências Agronômicas, Botucatu – SP, Caixa Postal 237. CEP: 18.610-307. E-mail: tecchio@fca.unesp.br; sarinel@fca.unesp.br.2 Eng. Agrônomo, Doutor, Pesquisador, Monsanto do Brasil, Uberlândia - MG. CEP: 38400-00. Email: Tatiana.merlin@monsanto.com3 Eng. Agrônomo, Doutor, Departamento de Solos e Recursos Ambientais, Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Faculdade de Ciências Agronômicas, Botucatu – SP, Caixa Postal 237. CEP: 18.610-307. E-mail: heliograssi@fca.unesp.br. 1 RESUMO A produção de mudas em viveiros telados é o alicerce da citricultura paulista e o manejo da adubação constitui-se num dos principais entraves do processo. Nessas condições, a deficiência e o excesso de cobre em mudas cítricas tornou-se um sério problema para os viveiristas. Nesse cenário, realizou-se o presente trabalho com o objetivo de avaliar os efeitos da aplicação cúprica em mudas cítricas. O experimento foi realizado em viveiro comercial localizado na cidade de Botucatu/SP e consistiu na aplicação de cinco tratamentos: T1 – testemunha, T2 - oxicloreto de cobre (1,8 g L-1), T3 - óxido cuproso (500 g L-1), T4 - quelato de cobre EDTA (0,04 mL L-1) e T5 - sulfato de cobre (2,5g L-1). Após a aplicação dos tratamentos, foram realizadas avaliações a cada 30 dias, durante 5 meses, da altura média de planta (cm), diâmetro médio do caule (mm), massa de matéria seca da parte aérea e radicular (g) e teor médio de cobre nas folhas (mg kg-1) do porta enxerto de limoeiro 'Cravo' (Citrus limonia, Osbeck), nas duas primeiras avaliações e na variedade copa laranjeira 'Valência' (Citrus sinensis, Osbeck), nas três avaliações posteriores. O delineamento experimental foi o inteiramente casualizado com parcelas subdividas no tempo, onde as parcelas corresponderam aos tratamentos com cobre e as subparcelas aos meses de avaliação. Independentemente da fonte de cobre utilizada houve incrementos nas variáveis de crescimento avaliadas. O teor médio de cobre apresentou valores considerados excessivos, principalmente para os produtos aplicados via foliar.Palavras-chaves: Citrus limonia; Citrus sinensis; fibra de coco; crescimento. TECCHIO, M. A.; MERLIM, T. P. A.; LEONEL, S.; GRASSI FILHO, H. COPPER FERTILIZATION IN CITRIC SEEDLINGS 2 ABSTRACT Seedling production in protected nursery is the basis of the São Paulo state citrus culture, and fertilization management is one of the main pitfalls in the process. Copper deficiency and excess in citrus seedlings have become a serious concern for seedling nursery owners. Based on these considerations, the study aimed at evaluating the effects of copper fertilization on citrus seedlings. The experiment was carried out at a commercial seedling nursery in Botucatu city/SP and consisted of 5 treatments: T1 – control, T2 – copper oxyfluoride (1.8 g L-1), T3 – cupric oxide (500 g L-1), T4 – copper chelate EDTA (0.04 mL L-1) and T5 – copper sulphate (2,5g L-1). After treatment allocation, monthly evaluations were performed for 5 months for mean plant height (cm), mean stem diameter (mm), above ground and root dry matter (g) and mean copper level in the leaves (mg kg-1) of the rootstocks of the rangpur lime (Citrus limonia, Osbeck) in the two first evaluations. The three following evaluations were performed in the “Valencia” orange cultivar (Citrus sinensis, Osbeck). The experiment was completely randomized with a split plot design, in which plots corresponded to treatments with copper fertilization, and subplots to months of evaluation. Tj<0} Mean values of copper were considered excessive, mostly in the products applied to the leaves.Keywords: Citrus limonia; Citrus sinensis; coconut fiber; growth.
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Žindžiuvienė, Ingrida Eglė. "Nostalgia for the Lost Homeland as Part of Identity in Alė Rūta’s Works." Jednak Książki. Gdańskie Czasopismo Humanistyczne, no. 9 (April 24, 2018): 97–108. http://dx.doi.org/10.26881/jk.2018.9.09.
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The article examines the representation of nostalgic memory of the lost homeland, Lithuania, in the Lithuanian diaspora writer’s, Alė Rūta’s (1915-2011), trilogy called “The Destiny of the Exiled”, which consists of the novels Pirmieji svetur (1984; Eng. - The First Abroad), Daigynas (1987; Eng. – The Seedling Plot), and Skamba tolumoj (1997; Eng. Echoes from Afar). These novels describe the multilayered problems of Lithuanian immigration into the U.S.A. and life of the immigrants there. Alė Rūta (Elena Nakaitė-Arbienė) is a well-known Lithuanian author, most of whose works (novels and collections of short stories and poems, all written in the Lithuanian language) have been published by the publishers of Lithuanian diaspora in the United States of America. The trauma of the loss of the native land results in the transmitted nostalgia in her novels. The author both mourns over the lost homeland and shares with the readers her grief over this loss and longing for seeing it again. In doing this, Alė Rūta echoes the nostalgic voices of many immigrants, who left their native country at different periods. The article also discusses the issue of preservation of ethnic identity, which is constructed on nostalgic and often melancholic memories of the past, and explores different types of nostalgia, which forms a core of Alė Rūta’s trilogy.
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Moore, James A., Zhaofei Fan, and Bahman Shafii. "Effect of Root-Plug Incorporated Controlled-Release Fertilizer on Two-Year Growth and Survival of Planted Ponderosa Pine Seedlings." Western Journal of Applied Forestry 17, no. 4 (2002): 216–19. http://dx.doi.org/10.1093/wjaf/17.4.216.
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Abstract Three controlled-release fertilizers (fast release [FR], moderate release [MR], and slow release [SR]) were incorporated in the root plug at rates of 0.8, 1.6, or 3.2 g/seedling at the time of sowing as supplements to nursery supplied soluble fertilizer. Effects on seedling growth, survival, and foliar nutrient status of the “160/90” container ponderosa pine (Pinus ponderosa) were evaluated after outplanting. At the end of the second growing season, fertilized seedlings had significantly greater diameter and height than unfertilized seedlings. The 3.2 g of MR or SR fertilizer treatments produced significantly higher mortality (55 and 36%, respectively) than the controls. The fast release fertilizer included at a rate of 0.8 g in each seedling's container was the preferred treatment since it produced good survival and seedling growth response. A 2-yr growth response of about 25% was similar to that observed in a nearby study using adjacent placement of controlled-release fertilizer after planting ponderosa pine seedlings. West. J. Appl. For. 17(4):216–219.
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Sá, Francisco Vaniés da Silva, Marcos Eric Barbosa Brito, Ilkelan Bezerra Pereira, Pedro Antônio Neto, Luderlandio De Andrade Silva, and Franciscleudo Bezerra da Costa. "BALANÇO DE SAIS E CRESCIMENTO INICIAL DE MUDAS DE PINHEIRA (Annona squamosa L.) SOB SUBSTRATOS IRRIGADOS COM ÁGUA SALINA." IRRIGA 20, no. 3 (2015): 544–56. http://dx.doi.org/10.15809/irriga.2015v20n3p544.
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BALANÇO DE SAIS E CRESCIMENTO INICIAL DE MUDAS DE PINHEIRA (Annona squamosa L.) SOB SUBSTRATOS IRRIGADOS COM ÁGUA SALINA FRANCISCO VANIES DA SILVA SÁ1; MARCOS ERIC BARBOSA BRITO2; ILKELAN BEZERRA FERREIRA3; PEDRO ANTÔNIO NETO3; LUDERLÂNDIO DE ANDRADE SILVA3 E FRANCISCLEUDO BEZERRA DA COSTA2 1 Eng. Agrônomo, Mestrando em Manejo de Solo e Água, Departamento de Ciências Ambientais e Tecnologia, Universidade Federal Rural do Semiárido, Mossoró, RN. E-mail: vanies_agronomia@hotmail.com2 Eng. Agrônomo, Doutor, Professor da Unidade Acadêmica de Ciências Agrárias, Universidade Federal de Campina Grande, Pombal, PB. E-mail: marcoseric@ccta.ufcg.edu.br; franciscleudo@yahoo.com.br3 Graduando em Agronomia, Unidade Acadêmica de Ciências Agrárias, Universidade Federal de Campina Grande, Pombal, PB. E-mail: kelanb.ferreira@hotmail.com; pedroantonioufcg@gmail.com; luderlandioandrade@gmail.com 1 RESUMO A salinidade da água e do solo são problemas que mais concorrem para redução no crescimento e rendimento das culturas, notadamente em regiões áridas e semiáridas, observando-se na identificação de estratégias de manejo, uma alternativa para os sistemas de produção. Assim, objetivou-se avaliar o uso de dois substratos na fase de formação de mudas de pinheira sob irrigação com águas salinizadas. O experimento foi realizado em casa de vegetação no município de Pombal, PB, Brasil, no período de maio a julho de 2011, sob delineamento experimental de blocos casualizados, com tratamentos distribuídos em esquema fatorial (5x2), sendo cinco níveis de salinidade da água (NS= 0,3; 1,2; 2,4; 3,6; 4,8 dS m-1) e dois substratos (S) (S1= 50% de solo + 25% de esterco bovino + 25% de areia; S2= 40% de solo + 40% de esterco bovino + 20% de areia), repetido em três blocos, totalizando trinta parcelas experimentais, sendo cada uma constituídas por 10 plantas. O experimento foi conduzido durante 45 dias após a semeadura, quando foram avaliadas as características químicas do solo, a emergência e o crescimento inicial das plantas. A irrigação com água salina aumentou a salinidade do substrato, sendo está menos intensa no substrato 2. As altas concentrações de sais na água de irrigação inibem a emergência, o crescimento e o ganho de biomassa das plântulas de pinheira. As plantas de pinheira alcançaram o melhor desenvolvimento quando cultivadas no substrato 2. A salinidade da água de irrigação até 1,2 dSm-1 não compromete a formação de mudas de pinheira. Palavras-chave: estresse salino, formação de mudas, matéria orgânica. SÁ, F.V.S; BRITO, M.E.B.; FERREIRA, I.B.; ANTÔNIO NETO, P.; SILVA, L.A.; COSTA, F.BSALT BALANCE AND INITIAL GROWTH OF CUSTARD APPLE UNDER SUBSTRATES IRRIGATED WITH SALINE WATER 2 ABSTRACT Water and soil salinity are the major pitfalls which contribute to reduction in growth and crop yield, especially in arid and semiarid regions. Identification of management strategies is an alternative tool for the crop system. Thus, the objective of this study was to evaluate the use of two substrates in the seedling stage of custard apple under irrigation with saline water. The experiment was carried out in a greenhouse in the municipality of Pombal, PB, Brazil, from May to July 2011, using randomized blocks and treatments in a factorial design (5 x 2) with five levels of water salinity ( 0.3; 1.2; 2.4; 3.6 and 4.8 dS m-1). Two substrates (S) (S1 = 50% soil + 25% manure + 25% sand; S2 = 40% soil+ 40% manure + 20% sand) repeated in three blocks were used, amounting to 30 plots with 10 plants each. The experiment was conducted for 45 days after sowing, and then, chemical characteristics of the soil solution, emergence and initial growth of plants were evaluated. Irrigation with saline water increased substrate salinity, which was lower in the substrate 2. High concentrations of salts in the irrigation water inhibited emergence, growth and gain of biomass of custard apple seedlings. Plants of custard apple achieved their best development when cultivated in the substrate 2 containing 40% soil, 40% manure and 20% sand. Salinity of irrigation water up to 1.2 dSm-1 did not compromise seedling growth of custard apple. Keywords: Annona squamosa L., salt stress, seedling production, organic matter.
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Marler, Thomas E., and April N. Cascasan. "Number of emerged seedlings and seedling longevity of the non-recruiting, Critically Endangered Håyun lågu Tree Serianthes nelsonii Merr. (Fabales: Leguminosae) are influenced by month of emergence." Journal of Threatened Taxa 7, no. 15 (2015): 8221. http://dx.doi.org/10.11609/jott.2100.7.15.8221-8225.
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<p>Emergence and longevity of seedlings beneath Guam’s only known Håyun lågu Tree <em>Serianthes nelsonii</em> were studied to determine the fate of every observed seedling during 2013. Newly emerged seedlings were marked with wire stakes every 15 days, then the stakes were collected at each seedling upon death. Longevity of each seedling was calculated from the marked ending and emergence dates. The least number of newly emerged seedlings was recorded at the end of the dry season, and the greatest number of newly emerged seedlings was recorded in the beginning of the rainy season. More than half of the year’s 374 seedlings died in less than 30 days. Seedling longevity ranged from a mean of 31 days for seedlings that emerged in May to 78 days for seedlings that emerged in June. Our results reveal that the baseline level of recruitment potential of the lone survivor of this species on Guam is substantial, and underscore the need for further research to determine the factors associated with the acutely limited seedling lifespan.</p><div> </div>
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Aizen, Marcelo A., and Hilary Woodcock. "Effects of acorn size on seedling survival and growth in Quercus rubra following simulated spring freeze." Canadian Journal of Botany 74, no. 2 (1996): 308–14. http://dx.doi.org/10.1139/b96-037.
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Seed size is an important phenotypic trait commonly associated with the fitness of young seedlings exposed to environmental stress. Spring frosts can cause leaf necrosis and seedling mortality in young oak seedlings, and seedling mortality following spring freeze events is a factor limiting the northern range limits of Quercus gambelii (Nutt.). We examined the relationship between acorn size and seedling survival following spring freeze by exposing 1-month-old Quercus rubra (L.) seedlings from two sites in Massachusetts to −3 °C for 8 h. Mortality of 1-month-old frost-exposed seedlings (20–25%) was 10 times higher than control mortality, with survival directly related to acorn size. Seedling size at the end of the first growing season was negatively affected by frost exposure and positively associated with acorn size. Overwintering mortality (<5%) was negatively associated with seedling size. The production of large acorns should confer a selective advantage in habitats susceptible to spring frosts through a positive effect on seedling establishment success under stress. Keywords: red oak, acorn size, frost, seedling survival.
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Lazreg, F., L. Belabid, J. Sanchez, E. Gallego, J. A. Garrido-Cardenas, and A. Elhaitoum. "First Report of Fusarium equiseti Causing Damping-Off Disease on Aleppo Pine in Algeria." Plant Disease 98, no. 9 (2014): 1268. http://dx.doi.org/10.1094/pdis-02-13-0194-pdn.
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The Aleppo pine (Pinus halepensis Mill.) is a conifer native to the Mediterranean region. In 2008 and 2009, a survey of Aleppo pine seedling diseases was performed in three forest nurseries from Relizane, Sidi Bel Abbes, and Tlemcen provinces in northwestern Algeria. Aleppo pine seedlings showed symptoms of pre- and post-emergence damping-off disease, with an incidence of 64 to 77%. Four composite samples were taken from each location. Disinfested root and root collar segments, approximately 5 mm in length, were cultured on potato dextrose agar (PDA) and incubated at 25°C, and hyphal tips were transferred to PDA. Fusarium equiseti (Corda) Sacc. (teleomorph: Gibberella intricans Wollenw.) was identified from roots of two seedlings from the Sidi Bel Abbes nursery. Morphological identification was done according to Fusarium keys (2). PDA colonies with abundant, loosely floccose, whitish aerial mycelium and beige pigmentation were observed. Macroconidia with usually 5 to 6 septa, 31 to 45 μm long. A pronounced dorsiventral curvature, tapered and elongated apical cell, and prominent foot shape were observed. Microconidia were absent. Chlamydospores were produced in hyphae, most often intercalary, solitary, in pairs, frequently forming chains or clusters, globose (7 to 13 μm). To confirm the identity of this fungus, the internal transcribed spacer of F3RS1 and F19RS1 isolates of F. equiseti were amplified and sequenced using ITS1 and ITS4 primers (4), GenBank accession nos. JX114784 and JX114791, respectively. Those sequences bore 100% (HQ671182) similarity with sequences of F. equiseti in GenBank. Pathogenicity tests were performed to fulfill Koch's postulates. Inoculum was produced by adding a 5-mm-diameter plug from a 7-day-old CMA petri dish culture to a previously sterilized 500 ml flask (237.5 g sand, 12.5 g cornmeal, 80 ml sterile distilled water), shaken over 9 days at 25°C, and mixed with sterile sandy clay soil at 1:3 (v:v). Infested soil was then transferred to 500 ml pots, and 10 Aleppo pine seeds were planted per pot. A completely randomized design was used with three replicates per isolate and three control pots with a similar non-infested soil. After 1 month at 25°C the two tested isolates caused typical damping-off symptoms (collar rot) on seedlings and were re-isolated from recently infected tissues. The percentages of the inoculated plants that became infected were 59 to 65% among isolates (0% in control pots). To our knowledge, infection by F. equiseti is a first report on Aleppo pine in northwestern Algeria, Northern Africa, and globally, and on conifers in the Mediterranean region (1,3). In Algeria, F. equiseti is associated with black pepper (Piper nigrum L.) (3). These findings highlight the moderate impact of F. equiseti on the production of Aleppo seedling stock for reforestation activities in northwestern Algeria. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases, Systematic Mycology and Microbiology Laboratory. ARS, USDA, Beltsville, MD. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , February 20, 2013. (2) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Ames, IA, 2006. (3) D. W. Minter. Cybertruffle's Robigalia, Observations of Fungi and their Associated Organisms. Retrieved from http://www.cybertruffle.org.uk/robigalia/eng/ , February 20, 2013. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.
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Lazreg, F., L. Belabid, J. Sanchez, E. Gallego, J. A. Garrido-Cardenas, and A. Elhaitoum. "First Report of Fusarium chlamydosporum Causing Damping-Off Disease on Aleppo Pine in Algeria." Plant Disease 97, no. 11 (2013): 1506. http://dx.doi.org/10.1094/pdis-02-13-0208-pdn.
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The Aleppo pine (Pinus halepensis Mill.) is a conifer native to the Mediterranean region. In 2008 and 2009, a survey of Aleppo pine seedling diseases was performed in three forest nurseries from the Relizane, Sidi Bel Abbes, and Tlemcen departments in northwestern Algeria. One- to two-month-old Aleppo pine seedlings showed symptoms of damping-off in pre- and post-emergence (typical seedling collar rot). The problem was widespread with a disease incidence of 64 to 77% and an annual impact of US$50,000. Disinfested root and root collar segments (from four composite samples per location), approximately 5 mm in length, were cultured on PDA and incubated at 25°C and day/night light. Two (from 21) isolates were identified morphologically (2) as the anamorph Fusarium chlamydosporum Wollenw. & Reinking and isolated from collar rots of Relizane forest nursery seedlings. Colony development on PDA media was fast; 32 mm diameter colonies developed after 3 days. Colonies were white. Mycelia were floccose, fairly dense, off-white, and turned a lilac color in older portions of the colony. Macroconidia were thick-walled and moderately curved with unequal dorsiventral curvature (the lower wall is almost straight), short, curved and pointed apical cell, usually notched, but occasionally foot shaped basal cell, 3- to 5-septate, and 2 × 8 to 21 μm. Microconidia were abundant, 0-septate, and 2 × 6 to 9 μm. Chlamydospores were abundant, formed rapidly in single chains or clusters, and 8 to 15 μm diameter. To confirm the identity of this fungus, the internal transcribed spacer of F12RR and F4SR isolates of F. chlamydosporum were amplified and sequenced using ITS1 and ITS4 primers (4). Sequences were deposited in GenBank under accessions JX114795 and JX114789, respectively. Those sequences bore 99% similarity with reference sequence AY213655 (2) and 100% with HQ671187, also found 99 to 100% similarity with F. equiseti (Corda) Sacc. but with different conidia. Pathogenicity tests were performed to fulfill Koch's postulates. Inoculum was produced by adding a 5 mm diam. plug from a 7-day-old CMA petri dish culture to a previously sterilized 500 ml flask (237.5 g sand, 12.5 g cornmeal, 80 ml SDW), shaken over 9 days, and mixed with sterile soil at 1:3 (v:v). Infested soil was then transferred to 500 ml pots, and 10 seeds were planted. A completely randomized design was used with three replicates per isolate and three control pots. After 1 month, two tested isolates caused typical damping-off symptoms on seedlings. The percentage of the plants that became infected was 65 to 77%. To our knowledge (1,3), this is the first report of F. chlamydosporum on Aleppo pine in northwestern Algeria. It is also the first report of this fungal species affecting the Aleppo pine throughout the world, and on conifers in Africa and the Mediterranean region (1,3). References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases, Syst. Mycol. Microbiol. Lab. ARS, USDA, Beltsville, MD. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , February 20, 2013. (2) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Ames, IA, 2006. (3) D. W. Minter. Cybertruffle's Robigalia, Observations of Fungi and their Associated Organisms. Retrieved from http://www.cybertruffle.org.uk/robigalia/eng/ , February 20, 2013. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.
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Castro, Jorge, and Alexandro Leverkus. "Effect of Herbaceous Layer Interference on the Post-Fire Regeneration of a Serotinous Pine (Pinus pinaster Aiton) across Two Seedling Ages." Forests 10, no. 1 (2019): 74. http://dx.doi.org/10.3390/f10010074.
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Herbaceous vegetation is a major source of interference with the regeneration of woody species. This is particularly the case after forest fires, as a dense herbaceous layer usually regenerates naturally. Although the competitive effect of the herbaceous vegetation upon tree seedlings has been widely studied, there are still gaps in knowledge for management related to the effect of tree seedling age and size on the outcome of the interaction. In this study, we seek to determine the response of maritime pine (Pinus pinaster Aiton) seedlings to herbaceous competition at two different seedling ages. For that, two treatments of herbaceous competition were implemented, namely unweeded (no action around pine seedlings) and weeded (herbaceous cover removed around pine seedlings). Treatments were conducted twice (2 and 4 years after the fire), and we monitored seedling survival and growth at the end of each growing season. The treatments were implemented across three adjacent landscape units that differed in the management of burned wood and that are representative of common post-fire scenarios: no intervention, salvage logging, and an intermediate degree of intervention. Weeding increased seedling survival from 44.7% to 67.8% when seedlings were 2 years old, but had no effect for four-year-old seedlings, which showed 99% survival. Seedling growth also increased in the weeding treatment, but only slightly. Moreover, growth (and survival for two-year-old seedlings) was strongly correlated with initial seedling size, particularly in the case of two-year-old seedlings. Initial pine seedling height was strongly and positively correlated with the height of the herbaceous layer, supporting the existence of microsite features that promote plant growth above competitive effects. The results support that management actions conducive to foster post-fire pine forest restoration in this Mediterranean ecosystem should reduce herbaceous competition at early stages after fire (second or third year) and focus on larger seedlings.
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Mao, Hanping, Guoxin Ma, Luhua Han, Jianping Hu, Feng Gao, and Yang Liu. "A whole row automatic pick-up device using air force to blow out vegetable plug seedlings." Spanish Journal of Agricultural Research 18, no. 4 (2021): e0211. http://dx.doi.org/10.5424/sjar/2020184-17003.
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Aim of study: To develop a whole row automatic pick-up device using air force to blow out plug seedlings, to avoid the damage to seedlings that the current way of seedling picking by needle insertion induces.Area of study: Jiangsu Province, China.Material and methods: We designed a pick-up device which mainly consists of a seedling transporting device, a seedling air loosening device, a seedling clamping device and an automatic control system. The damage rate of seedling was significantly reduced and the success rate of seedling picking was increased by using the new seedling air loosening method and the new designed end-effectors. A prototype of the new pick-up device was produced according to the calculation results, and the performance tests were arranged under actual production conditions in an indoor laboratory.Main results: The calculation showed that when the diameter of the blowhole in air nozzle is 3.5 mm, and the air pressure is between 0.146 MPa and 0.315 MPa, the seedlings can be blown out successfully. Besides, the clamping strain test showed that the new designed end-effector can meet the requirements of seedling picking. The orthogonal test showed that both the air pressure and water content significantly affected the success ratio. The success ratio reached 96.64% when air pressure was 0.4 MPa, water content was 55%-60% and airflow rate was 100%, what meets the current requirements of transplanting.Research highlights: This research can provide some references for the automatic transplanting technology.
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Saunders, Mike R., and Klaus J. Puettmann. "Effects of overstory and understory competition and simulated herbivory on growth and survival of white pine seedlings." Canadian Journal of Forest Research 29, no. 5 (1999): 536–46. http://dx.doi.org/10.1139/x99-017.
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The interactive impact of overstory canopy closure, understory brush control, and simulated white-tailed deer (Odocoileus virginianus Zimmermann) herbivory (i.e., clipping) on growth and survival of underplanted white pine (Pinus strobus L.) seedlings was examined. Clipping was conducted in April 1996 and 1997 at three intensities (control, 0% previous year's growth removed; lightly clipped, terminal and 50% previous year's growth removed, and heavily clipped: 100% of previous-year's growth removed) and three frequencies (never clipped, clipped once, clipped 2 years in a row). Decreasing overstory canopy closure and brush competition generally increased growth of seedlings under all clipping regimes, with heavily clipped seedlings showing the least benefit of reduced competition. Although first-year height growth was stimulated after light-intensity clipping, this effect did not persist the following year, and these trees still were significantly shorter than controls at the end of the experiment. Diameter growth was reduced at any clipping intensity or frequency, and remained below controls throughout the experiment. Seedling mortality was higher without brush control and after clipping. Results suggest that increased overstory and understory competition reduced seedling growth and survival. In regards to clipping, initial height growth stimulation may result from (i) resource reallocation away from diameter and root growth and (or) (ii) hormonal redistributions from loss of apical control in the seedling. Since both high competition levels and increased herbivory reduced seedling vigor, we suggest that understory brush control and deer protection (e.g., budcapping) go hand in hand to regenerate white pine.
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Bach, Catherine E. "Seedling Survivorship of the Beach Morning Glory, Ipomoea pes-caprae (Convolvulaceae)." Australian Journal of Botany 46, no. 1 (1998): 123. http://dx.doi.org/10.1071/bt96118.
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Factors influencing seedling survivorship in the beach morning glory, Ipomoea pes-caprae (L.) Roth, were studied near Townsville, Queensland, Australia. Censuses of recently germinated seedlings revealed an 83% mortality rate over a period of 11 weeks. Seedlings that died occurred significantly further above high-tide line than did seedlings that were still alive at the end of the study. Although distance to the nearest neighbouring plants did not influence the probability of survival, more seedlings survived if their nearest neighbours were monocots than if they were conspecifics. The probability of survival was greater for seedlings which were closer to neighbouring seedlings of I. pes-caprae, but distance to the nearest adult I. pes-caprae did not affect survival. There was 100% mortality of seedlings that were naturally buried by sand. A field experiment manipulated levels of insect herbivory and sand burial, and showed that herbivory caused a seven-fold increase in mortality rate. Although sand burial also increased mortality, this effect was not significant. Overall, seedling mortality appeared to be influenced by both abiotic factors (location on beach, sand burial) and biotic factors (seedling density, neighbour type and herbivory).
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Duchesneau, Robin, and Hubert Morin. "Early seedling demography in balsam fir seedling banks." Canadian Journal of Forest Research 29, no. 10 (1999): 1502–9. http://dx.doi.org/10.1139/x99-090.
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Following the 1995 mast year, we conducted detailed seedling demography surveys to characterize some ecological factors affecting germination and early establishment in understory balsam fir (Abies balsamea (L.) Mill.) seedling banks and verify if recruitment from a cohort can potentially renew the balsam fir seedling bank. Twenty-five seed traps paired with 32 demography subplots were located in each of four permanent plots and regularly monitored over a 2-year period. Spatial patterns of newly emerged seedlings generally corresponded to those found for seed dispersal. However, at the end of the monitoring period, the spatial pattern of surviving seedlings was independent of the seed dispersal pattern. Seedbed types and understory light environments were the main factors explaining seedling mortality. Sphagnum mosses and decaying wood were the most favorable seedbeds for early establishment. The 0- to 25-cm seedling populations grew in size because of the addition of new recruits. If, in the years to come, mortality rates of the 1995 cohorts were similar to those of already established 0- to 25-cm seedlings, mast years of seed production, at least during endemic periods, would be crucial for recruitment and renewal of balsam fir seedling banks.
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Dranski, João Alexandre Lopes, Ubirajara Contro Malavasi, and Marlene de Matos Malavasi. "RELATIONSHIP BETWEEN LIGNIN CONTENT AND QUALITY OF Pinus taeda SEEDLINGS1." Revista Árvore 39, no. 5 (2015): 905–13. http://dx.doi.org/10.1590/0100-67622015000500013.
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ABSTRACT The essay objective was to correlate lignin content resulting from tigmomorphogenesis induced by stem swaying with survival and post-planting growth of P. taeda seedlings. Seedlings were subjected to daily frequencies (0, 5, 10, 20 and 40 movements) of stem swaying for 60 days. By the end of the treatments, we determined lignin content of below and aboveground seedling tissues. Four replicates per treatment were planted in a area cultivated with pines. Ninety days after planting, survival and increments of seedling height, stem diameter and stem volume were quantified. Application of 20 stem swayings increased lignin in both below and aboveground plant tissues. Outplanted seedling survival was reduced with 40 stem swayings while growth increments were increased with both 10 and 20 stem swayings. Lignin content from belowground plant tissues was positively correlated with outplanted seedling survival while lignin from aboveground tissues correlated with height and stem volume increments. P. taeda seedlings with higher lignin content have higher survival chances after planting.
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Tang, Jiao, Carlos Alberto Busso, Deming Jiang, et al. "Experimental sand burial affects seedling survivorship, morphological traits, and biomass allocation of <i>Ulmus pumila</i> var. <i>sabulosa</i> in the Horqin Sandy Land, China." Solid Earth 7, no. 4 (2016): 1085–94. http://dx.doi.org/10.5194/se-7-1085-2016.
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Abstract. As a native tree species, Ulmus pumila var. sabulosa (sandy elm) is widely distributed in the Horqin Sandy Land, China. However, seedlings of this species have to withstand various depths of sand burial after emergence because of increasing soil degradation, which is mainly caused by overgrazing, climate change, and wind erosion. An experiment was conducted to evaluate the changes in its survivorship, morphological traits, and biomass allocation when seedlings were buried at different burial depths: unburied controls and seedlings buried vertically up to 33, 67, 100, or 133 % of their initial mean seedling height. The results showed that partial sand burial treatments (i.e., less than 67 % burial) did not reduce seedling survivorship, which still reached 100 %. However, seedling mortality increased when sand burial was equal to or greater than 100 %. In comparison with the control treatment, seedling height and stem diameter increased at least by 6 and 14 % with partial burial, respectively. In the meantime, seedling taproot length, total biomass, and relative mass growth rates were at least enhanced by 10, 15.6, and 27.6 %, respectively, with the partial sand burial treatment. Furthermore, sand burial decreased total leaf area and changed biomass allocation in seedlings, partitioning more biomass to aboveground organs (e.g., leaves) and less to belowground parts (roots). Complete sand burial after seedling emergence inhibited its re-emergence and growth, even leading to death. Our findings indicated that seedlings of sandy elm showed some resistance to partial sand burial and were adapted to sandy environments from an evolutionary perspective. The negative effect of excessive sand burial after seedling emergence might help in understanding failures in recruitments of sparse elm in the study region.
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Krueger, Jerome A., and Klaus J. Puettmann. "Growth and Injury Patterns of Eastern White Pine (Pinus strobus L.) Seedlings as Affected by Hardwood Overstory Density and Weeding Treatments." Northern Journal of Applied Forestry 21, no. 2 (2004): 61–68. http://dx.doi.org/10.1093/njaf/21.2.61.
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Abstract White pine seedlings were underplanted under a range of overstory densities in a hardwood stand in northern Minnesota. Vegetation surrounding seedlings was left untreated (control), weeded annually, or completely removed through monthly weeding. After 4 years, the benefit of weeding woody competition for diameter growth of seedlings was limited to areas with relatively open overstory conditions. Seedling height growth was reduced in areas with higher overstory density, but improved through weeding treatments that removed woody vegetation. The removal of herbaceous vegetation did not improve growth of seedlings in any conditions. Open growing conditions created by overstory removal and weed control resulted in higher incidences of seedling injuries, e.g., through infection by white pine blister rust. Conditions for pine bark adelgids also were enhanced in areas with low overstory densities and weeding treatments. The incidence for white pine weevil seems to follow a similar pattern, although the number of trees infected was minimal. Results show that improving growing conditions through management of the overstory and understory vegetation improves seedling growth rates, but must be balanced with potentially higher incidences of seedling injuries under more open conditions.
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Saani, Chinwe I., Joshua Kayode, Benson O. Ademiluyi, and M. Yoserizal Saragih. "Effect of Growth Media on Plumule Emergence and Early Seedling Growth of Monodora myristica." Budapest International Research in Exact Sciences (BirEx) Journal 2, no. 4 (2020): 436–42. http://dx.doi.org/10.33258/birex.v2i4.1257.
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The study investigated the emergence and early seedling development of Monodora myristica in six different growth media viz: mixture of river sand/top soil, river sand/saw dust, top soil/saw dust, saw dust only, top soil only and river sand only. Results obtained recorded highest percentage germination (63%) in seeds sown in saw dust only. Early seedling growth was observed for four months. The results of this study showed that seedlings sown in mixture of top soil/saw dust recorded highest mean plant height (16.83cm), stem girth ( 2.50mm), and leaf area (46.18cm2) at the end of the experimental time. Seedlings on top soil only had the highest number of leaves (3.89). River sand had the least seedling performance in all the growth parameters examined; plant height (13.27cm), stem collar girth (1.99mm), leaf length (8.61cm), leaf width (4.77cm) and leaf area (30.83cm2). The study established that the % emergence of Monodora myristica seedlings was best in saw dust medium while mixture of top soil/saw dusts is recommended for enhancing early seedling growth of this plant in the nursery.
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Teixeira, Ednilson Carvalho, Sylvana Naomi Matsumoto, André Felipe Fialho Ribeiro, et al. "Morphophysiology and quality of yellow passion fruit seedlings submitted to inhibition of gibberellin biosynthesis." Acta Scientiarum. Agronomy 43 (July 5, 2021): e51541. http://dx.doi.org/10.4025/actasciagron.v43i1.51541.
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The aim of this study was to verify if a growth reduction of yellow passion fruit seedlings’ growth morphophysiology and quality could be changed by paclobutrazol applied through seedling immersion. The experiment was conducted in a greenhouse, with seedlings grown in polyethylene tubes (290 cm3), with substrate. At 40 days after sowing, the seedlings were immersed in an aqueous solution of paclobutrazol at concentrations of 0, 50, 100, 150, and 200 mg L-1. The experiment was conducted in a randomized block design, with five treatments (paclobutrazol concentrations) and four replicates. At 15 and 30 days after treatment, growth characteristics were evaluated. At the end of the assay, destructive evaluations related to mass determination, total leaf area, and seedling quality index were performed. Paclobutrazol treatment induced restrictions in seedling growth, except for fresh and dry mass of root and total fresh mass. Based on these characteristics, the increase in values induced by paclobutrazol was verified. The seedling quality, defined by the major value of the Dickson quality index and a smaller robustness index, was higher when submitted to paclobutrazol treatment.
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Tanner, E. V. J., V. K. Teo, D. A. Coomes, and J. J. Midgley. "Pair-wise competition-trials amongst seedlings of ten dipterocarp species; the role of initial height, growth rate and leaf attributes." Journal of Tropical Ecology 21, no. 3 (2005): 317–28. http://dx.doi.org/10.1017/s0266467405002269.
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To investigate whether seedlings of ten dipterocarp species differed significantly in terms of growth and mortality or whether species were not significantly different and could be considered ecologically similar, seedlings were grown, two per pot, in two experiments: (1) where the two seedlings were of equal height (30 cm); and (2) where one seedling was 10 cm shorter than the other. Seedlings were grown in a shade house with 15% above-canopy light in a 50:50 forest soil–sand mixture and were watered frequently; pots were placed so that seedling density was 130 seedlings m−2 of ground. In the first experiment there were 45 pairwise combinations of species when seedlings were 30 cm tall (AB, AC, AD,…. BC, BD…IJ; where A, B, C…J signify different species); each combination was replicated 10 times so there were 450 pots with 900 seedlings. In the second experiment there were 100 pairwise combinations of species and size e.g. Aa (30 cm A with 20 cm a), Ab (30 cm A with 20 cm b), each combination was replicated 10 times hence there were 1000 pots with 2000 seedlings. After 22 mo 79% of the initial 2900 seedlings survived; on average they had grown 42 cm (i.e. to 72 cm tall from their initial 30 cm). The most frequent outcome of competition-trials between different sized individuals (784 of 1000 trials) was that the initially taller seedling of each pair ‘won’ (it was the taller or surviving seedling). When 900 of these trials (setting aside, Aa, Bb, Cc etc.) were analysed as 45 comparisons between species with different sized individuals (Ab and aB are one interspecific comparison for these purposes), initial height determined the outcome in 23 cases (even in some competitions between light hardwood species and heavy hardwood species); in 6 cases a species (mostly light hardwoods) behaved as a ‘dominant’ – they usually won even if they were smaller initially. We found few significant differences between species in: initial seedling heights; leaf nitrogen concentrations; and specific leaf areas when they were grown in similar conditions, and these attributes were not correlated with growth rates. The similarity of seedlings of different species meant that often a height difference of just 10 cm was enough to determine the outcome of a pairwise competition-trial in high seedling densities and light equivalent to that in forest gaps.
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Woods, Michaela J., Meredith Cobb, Katie Hickle, and Ryan W. McEwan. "Assessing the Efficacy of Seedling Planting as a Forest Restoration Technique in Temperate Hardwood Forests Impacted by Invasive Species." Forests 10, no. 8 (2019): 699. http://dx.doi.org/10.3390/f10080699.
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The emerald ash borer (Agrilus planipennis Fairmaire; EAB) is an invasive insect that causes mortality of trees in the genus Fraxinus, creating canopy gaps that may facilitate invasion by exotic plants. Planting native tree seedlings under EAB-infested Fraxinus may accelerate succession and preclude invasive plant expansion; however, the effectiveness of this approach has not been experimentally tested. We assessed understory seedling planting of Quercus rubra, Carya laciniosa, and Juglans cinerea in EAB-infested forests, where the invasive shrub Lonicera maackii (Amur honeysuckle) was removed. We tested whether the use of plastic tree shelters (“tree tubes”) or planting season (fall versus spring) contributed to the success of the reforestation plan by measuring growth rates (cm/yr) and survivorship two and seven years after planting. After seven years, seedling survivorship was <25% for all species and planting techniques. Quercus rubra exhibited poor survivorship with one seedling surviving to the conclusion of the experiment. Juglans cinerea and C. laciniosa had higher survivability and growth rates than did Q. rubra after two and seven years. Effects of tree tubes were weak and temporary. After 2 years, Q. rubra seedling survivorship was higher in tree tubes; however, by the end of the experiment 29 of the 30 Q. rubra seedlings in tree tubes had died. Juglans cinerea seedlings grew faster when planted in the fall compared to the spring, but overall survivorship of these seedlings was unaffected by planting season. Neither the use of tree shelters nor the planting season contributed to the growth or survival of C. laciniosa seedlings. In summary, our results indicate that seedling planting of Carya and Juglans may be a useful way to increase biodiversity in regenerating forests; however, the resource-expensive processes of over-wintering seedlings and using tree shelters may not increase the success of reforestation efforts.
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Bannor, Richard Kwasi, Helena Oppong-Kyeremeh, Steffen Abele, Frank Osei Tutu, Samual Kwabena Chaa Kyire, and Dickson Agyina. "Seedling production and choice among cashew farmers in Ghana: a profitability analysis." World Journal of Entrepreneurship, Management and Sustainable Development 16, no. 2 (2020): 109–29. http://dx.doi.org/10.1108/wjemsd-11-2019-0089.
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PurposeThe unavailability and inadequate use of cashew seedlings for propagation are part of the challenges facing the cashew sub-sector in Ghana. However, promoting investment into cashew seedling production should be based on the analysis of the profitability and viability of such a venture as well as the respective determinants of farmers' demand for the planting material.Design/methodology/approachThis study used gross margin/contribution, net margin and contribution ratios to analyse the profitability of cashew seedling production under four different business models. Also, the determinants of choice of planting material for cashew plantation among farmers was analysed via a multinomial probit regression.FindingsThe study revealed that cashew seedling production is profitable with a gross margin of $8,474, $2,242, $1,616 and $1,797 and contribution to sales of 31–53% for the various business models. The positive determinants of the use of cashew seedlings were off-farm job participation and extension contact, whereas farm size and age of plantation negatively influenced the use of seedlings. Land acquisition method also influenced the use of both seedlings and seeds negatively.Practical implicationsThe findings provide empirical evidence of the viability and profitability of cashew seedling production as a viable business venture and off-farm opportunity in rural areas. The information from the study will help major stakeholders in cashew production to understand the type of farmers who use seeds and seedlings as well as the reasons for using or otherwise.Originality/valueSignificant research in the cashew value chain had focussed on the profitability of cashew plantation with little literature on profitability and viability analysis of cashew seedling production. Similarly, this study provides a significant value chain job opportunity as well as literature on the choice of cashew seedlings among current and prospective end-users.
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McLaren, Brian E., and Robert A. Janke. "Seedbed and canopy cover effects on balsam fir seedling establishment in Isle Royale National Park." Canadian Journal of Forest Research 26, no. 5 (1996): 782–93. http://dx.doi.org/10.1139/x26-088.
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While balsam fir (Abiesbalsamea (L.) Mill.) dominated forests are vanishing from the southwest end of Isle Royale National Park, Michigan, renewal of fir stands is occurring on the northeast end. We speculate that the difference is related both to severe browsing by moose (Alcesalces L.), and to the frequency of disturbances like fire and windthrow. A survey of 24 stands and in situ experimentation on Isle Royale show that balsam fir seedling survival is optimal under 40–79% canopy cover. Late-season and overwinter mortality in 1-year-old seedlings is highest under >80% canopy cover, while germination is lowest under <40% cover. We also rank germination substrates by "preference ratios," and by comparing the overwinter survival of young fir seedlings on five natural media. We find best performance on hypnaceous moss, variable survival success on rotten wood, and highest mortality on broadleaf litter. However, ample seedling densities occur on the southwest end of the island, and the failure of fir to reach the overstory in this area is apparently not related to poor seedling establishment.
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Sun, Qiaoyu, Yong Liu, Hongbin Liu, and R. Kasten Dumroese. "Interaction of Biochar Type and Rhizobia Inoculation Increases the Growth and Biological Nitrogen Fixation of Robinia pseudoacacia Seedlings." Forests 11, no. 6 (2020): 711. http://dx.doi.org/10.3390/f11060711.
Full textAbstract:
Adding biochar to soil can change soil properties and subsequently affect plant growth, but this effect can vary because of different feedstocks and methods (e.g., pyrolysis or gasification) used to create the biochar. Growth and biological nitrogen fixation (BNF) of leguminous plants can be improved with rhizobia inoculation that fosters nodule development. Thus, this factorial greenhouse study examined the effects of two types of biochar (i.e., pyrolysis and gasification) added at a rate of 5% (v:v) to a peat-based growth substrate and rhizobia inoculation (yes or no) on Robinia pseudoacacia (black locust) seedlings supplied with 15NH415NO3. Seedling and nodule growth, nitrogen (N) content, and δ15N × 1000 were evaluated after 3 months. While addition of biochar without inoculation had no effect on seedling growth, inoculation with rhizobia increased seedling growth, BNF, and N status. Inoculated seedlings had reduced δ15N, indicating that N provided via fertilization was being diluted by N additions through BNF. Biochar type and inoculation interacted to affect seedling growth. Combining inoculation with either biochar type increased seedling leaf, stem, and total biomass, whereas gasifier biochar and inoculation improved all seedling growth variables and nodule biomass.
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Jalkanen, Anneli. "Growth and Morphology of Black Spruce, Jack Pine, and White Spruce Container Seedlings in Northern Ontario." Northern Journal of Applied Forestry 12, no. 2 (1995): 69–74. http://dx.doi.org/10.1093/njaf/12.2.69.
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Abstract The development of morphological attributes of containerized seedlings during the growing season was studied in eight crops from three nurseries in Northern Ontario, including four black spruce crops, three jack pine crops, and one white spruce crop. The variability was proportionally largest in root and shoot dry mass, followed by height and diameter. During seedling growth, proportionally the variability of size did not seem to increase. In absolute scale, however, differences between individual seedlings increased more than differences between seedling trays, possibly due to competition between individuals. Height and shoot growth were greater in the beginning of the growing season, and diameter and root growth were greater toward the end. In comparison to standards, the balance between morphological attributes (height/diameter, shoot/root) was usually acceptable, and usually independent of seedling size. The easiest way of monitoring crop development is to take seedling samples at regular intervals and to construct a growth progression curve for seedling height, if diameter growth reaches acceptable level. Care should be taken that the height of seedlings does not increase too much at the expense of diameter and root development in the larger crops. To monitor this, height-diameter ratios and shoot-root ratios might be measured a couple of times during the growing season to take corrective action if necessary. North. J. Appl. For. 12(2):69-74.
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Chejara, V. K., P. Kristiansen, B. M. Sindel, R. D. B. Whalley, and C. Nadolny. "Seed-bank and seedling dynamics in Hyparrhenia hirta are influenced by herbicide application and mowing management." Rangeland Journal 34, no. 2 (2012): 199. http://dx.doi.org/10.1071/rj11057.
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Hyparrhenia hirta (L.) Stapf (Coolatai grass) is a summer-active, C4 perennial tussock grass, native to southern Africa and the Mediterranean region, which has invaded areas of native flora in Australia in recent decades. Understanding its seed and seedling dynamics and how various management treatments (e.g. mowing, herbicide and no management) affect these may assist in identifying the conditions and management strategies required to limit its invasion. The population dynamics of H. hirta have not been comprehensively studied previously. A 2-year field experiment (December 2005–December 2007) was conducted to determine the seed-bank size, pattern of seedling emergence and survival of H. hirta seedlings at three sites in northern New South Wales, Australia, under three treatments: unmanaged (control), mowing and herbicide treatments. The density of H. hirta seeds in the soil at each experimental site under different treatments was measured in December 2005 at the start of the experiment, in December 2006 before the application of the second round of treatments and again at the end of the experiment in December 2007. Hyparrhenia hirta seedlings were assessed at monthly intervals in permanent quadrats (0.5 × 0.5 m) to determine seedling emergence and survival. Seedling emergence occurred on many occasions during the 2-year period of the experiment in each treatment and at all sites but the main seedling flushes were observed from mid summer to early autumn. In 2007, at all sites, seedling emergence declined by more than 90% on the mowing and herbicide treatments compared with the control treatment. Seedling survival was greater in the mowing and herbicide treatments than in the control treatment. The seedling cohorts emerging in winter had a lower survival. This study showed that H. hirta infestations have a large viable seed-bank (~3000 m–2), dependent on the level of infestation and climatic conditions, but that the seed-bank declines rapidly when seed addition is prevented. Some form of direct control of established H. hirta plants in combination with providing appropriate grazing management to encourage competition between grasses will assist in the control of H. hirta.
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Fraedrich, Stephen W., and L. David Dwinell. "Effects of Dazomet, Metam Sodium, and Oxamyl on Longidorus Populations and Loblolly Pine Seedling Production." Southern Journal of Applied Forestry 29, no. 3 (2005): 117–22. http://dx.doi.org/10.1093/sjaf/29.3.117.
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Abstract Dazomet, metam sodium, and oxamyl were evaluated for nematode control and production of loblolly pine seedlings in a field infested by a Longidorus sp. Fumigation with dazomet or metam sodium reduced population densities of Longidorus to nondetectable levels early in the growing season but population densities subsequently increased to levels found in untreated control plots by the end of the growing season. Oxamyl had no effect on Longidorus population densities. Seedlings in dazomet-treated plots had significantly greater root and shoot weights than seedlings in control and oxamyl-treated plots within 6 weeks of seed sowing. At the end of the growing season, seedlings in the control and oxamyl plots were very stunted with poorly developed root systems. Seedling shoot length and root collar diameter in dazomet-treated plots averaged 27.4 cm and 4.0 mm, respectively, but in nonfumigated control plots these variables averaged 10.5 and 2.5 mm, respectively. Although dazomet and metam sodium were effective in reducing Longidorus populations for the first seedling crop after fumigation, production of a second crop without additional treatment would be inadvisable based on the increased population of Longidorus by the end of the first growing season. South. J. Appl. For. 29(3):117–122.
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Bal, Amandeep, and Christopher P. Chanway. "Evidence of nitrogen fixation in lodgepole pine inoculated with diazotrophic Paenibacillus polymyxa." Botany 90, no. 9 (2012): 891–96. http://dx.doi.org/10.1139/b2012-044.
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Diazotrophic bacteria previously isolated from internal tissues of naturally regenerating lodgepole pine ( Pinus contorta var. latifolia (Dougl.) Engelm.) seedlings were tested for their ability to colonize and fix nitrogen (N) in pine germinants in two experiments. Surface sterilized pine seed was sown in glass tubes containing an autoclaved sand – montmorillonite clay mixture that contained a N-limited nutrient solution labeled with 15N as 0.35 mmol·L–1 Ca(15NO3)2 (5% 15N label). Pine seed was inoculated with one of three of the following bacterial strains: Paenibacillus polymyxa P2b-2R, P. polymyxa P18b-2R, or Dyadobacter fermentans P19a-2R, and seedlings grew for either 27 or 35 weeks. At the end of each plant growth period, P. polymyxa strain P2b-2R was detected in the pine rhizosphere but not inside plant tissues. Pine foliar N concentrations were not affected by bacterial inoculation but significant foliar 15N dilution was observed in seedlings treated with strain P2b-2R (30% and 66%, P < 0.05, in the first and second experiments, respectively). This strain also reduced seedling biomass in both experiments but effects were significant only in the second experiment (36%, P < 0.05). Notwithstanding the negative effect of bacterial inoculation on seedling growth, pine seedlings inoculated with strain P2b-2R derived 30% and 66%, respectively, of their foliar N from bacterial N fixation in two seedling growth experiments. These results demonstrate the possibility that some endophytic diazotrophs facilitate pine seedling growth in N-poor soils.
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Fried, Jeremy S., John C. Tappeiner II, and David E. Hibbs. "Bigleaf maple seedling establishment and early growth in Douglas-fir forests." Canadian Journal of Forest Research 18, no. 10 (1988): 1226–33. http://dx.doi.org/10.1139/x88-189.
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Survival, age and height distributions, and stocking of bigleaf maple (Acermacrophyllum Pursh) seedlings were studied in 1- to 250-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands in western Oregon to identify the stages in stand development in which bigleaf maple is most likely to establish successfully from seed. Maple seedling emergence averaged 30–40% where seeds were planted and protected from rodents but was typically <2% for unprotected seeds. Seedling survival after 2 years was highly dependent on canopy density, measured by percent sky. Average 1st-year survival of seedlings originating from planted, protected seeds was highest in clearcuts (1–2 years old, 36% survival, 56% sky) and pole-size stands (41–80 years old, 30% survival, 17% sky) with sparse understories and canopies. It was lowest in young stands with dense canopies (20–40 years old, 4% survival, 8% sky) and old stands (81–250 years old, 14% survival, 13% sky) with dense understories. Naturally regenerated populations of bigleaf maple seedlings, which occurred in aggregations (0.005–0.04 ha in area), were most abundant (up to 10 000/ha) in pole-size Douglas-fir stands. Although seedling size distributions within stands had a strongly inverse J shaped form, size distributions within aggregations appeared more normal (bell-shaped). Seedling age rarely exceeded 15 years. Seedlings grew slowly in the understory, often reaching only 25 cm in height after 8–10 years, and were intensively browsed by deer. Naturally regenerated seedlings were virtually absent from clearcuts, probably because of dense competing vegetation and lack of seed caused by poor dispersal and seed predation. The "window" for the most successful establishment of bigleaf maple seedlings appears to begin after canopy thinning and end before forbs and shrubs invade.
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Polanía, Brayan S., Ana M. Aldana, Marius Bottin, et al. "Effect of Seasonal Rains and Floods on Seedling Recruitment and Compositional Similarity in Two Lowland Tropical Forests." Forests 11, no. 12 (2020): 1297. http://dx.doi.org/10.3390/f11121297.
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Research Highlights: Seasonally flooded and terra firme forests are characteristic ecosystems of the Colombian Orinoco Basin and of great importance in the maintenance of regional biodiversity and ecosystem function. These forests have a unimodal precipitation regime that can cause a temporal effect on the seedling regeneration niche. This could partly explain the high diversity and coexistence of plant species in these forests, as well as the similarity in composition of seedlings and trees. Background and Objectives: Seedlings are a key factor in the assembly of plant communities. We evaluated the effect of flooding and rains on the dissimilarity and compositional affinity between trees and seedlings of seasonally flooded and terra firme forests. Materials and Methods: the tree community of these forests in San Martín (Meta, Colombia) was characterized and compared with their respective seedling communities before (June) and after (December) rain and flooding (during the rainy season). We evaluated plant species diversity and abundance (Shannon diversity and Pielou eveness index), as well as the compositional dissimilarities of each tree community with their corresponding seedling community sampled at the beginning and end of rains and flooding (Bray–Curtis dissimilarity). We also compared sampling site composition using a NMDS analysis. Results: We found that the terra firme forest had higher diversity compared to the flooded forest. Seedling density in the seasonally flooded forest decreased significantly after the flood but not in the terra firme forest at the end of the rainy season. The compositional dissimilarity between trees and seedlings in the seasonally inundated forest also decreased after the flood. However, this pattern was not evident in the terra firme forest. Conclusions: These results indicate that seasonal flooding generates a strong ecological filter that affects the realized niche of plants in these forests. Our results can contribute valuable information for the effective development of assisted restoration and conservation programs.
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SILVA JUNIOR, FRANCISCO BARROSO DA, GEOCLEBER GOMES DE SOUSA, JOSÉ THOMAS MACHADO DE SOUSA, CARLA INGRYD NOJOSA LESSA, and FRED DENILSON BARBOSA DA SILVA. "SALT STRESS AND AMBIENCE ON THE PRODUCTION OF WATERMELON SEEDLINGS." Revista Caatinga 33, no. 2 (2020): 518–28. http://dx.doi.org/10.1590/1983-21252020v33n224rc.
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ABSTRACT The objective of this study was to evaluate the production of watermelon seedlings irrigated with saline waters and cultivated in different types of environments and substrates. The experimental design was completely randomized with split-split plots, in which the plot corresponded to two growing environments (EN1 = full sun and EN2 = 50% shade black net), the subplot to two types of irrigation water (IW1 = 0.8 and IW2 = 2.5 dS m-1) and the sub-subplot to four types of substrates (SB1 = vermiculite + coconut fiber, SB2 = manure + soil, SB3 = carbonized rice husk + soil, SB4 = biochar + soil), with four replicates of twenty-five seeds. The variables analyzed were: emergence percentage (EP), emergence speed index (ESI), mean time of emergence (MTE), number of leaves (NL), stem diameter (SD), seedling height (SH) and root length (RL), shoot dry mass (SDM), root dry mass (RDM) and total dry mass (TDM). The EN2 treatment provided better conditions for emergence and initial growth, and EN1 was also favorable to the emergence and initial growth of watermelon seedlings, when the substrates SB1 and SB2 were used.
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Turner, Monica, Rebecca Reed, William Romme, and Gerald Tuskan. "Distribution, Morphology, Survival, and Genetics of Aspen (Populus Tremuloides) Seedlings Following the 1988 Yellowstone Fires." UW National Parks Service Research Station Annual Reports 20 (January 1, 1996): 118–22. http://dx.doi.org/10.13001/uwnpsrc.1996.3303.
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An unexpected consequence of the 1988 Yellowstone fires was the widespread establishment of seedlings of quaking aspen (Populus tremuloides) in the burned forests, including areas outside the previous range of aspen (Kay 1993; Romme et al. 1997). Although aspen is the most widely distributed tree species in North America (Powells 1965), it is relatively uncommon and localized in distribution within Yellowstone National Park (Despain 1991). Most aspen stands in Yellowstone are found in the lower elevation landscapes in the northern portion of the park, and the species was absent - prior to 1988 -- across most of the high plateaus that dominate the southern and central park area. Aspen in the Rocky Mountain region reproduces primarily by means of vegetative root sprouting. Although viable seeds are regularly produced, establishment of seedlings in the wild is apparently a rare event due to the limited tolerance of aspen seedlings for desiccation or competition (e.g., Pearson 1914; McDonough 1985). In the immediate aftermath of the 1988 Yellowstone fires, there was a brief "window of opportunity" for aspen seedling establishment, as a result of abundant aspen seed production, moist weather conditions in spring and summer, and bare mineral soil and reduced plant competition within extensive burned areas (Jelinski and Cheliak 1992; Romme et al. 1997). We initiated this 3-year study in 1996 to address four questions about the aspen seedlings now growing in burned areas across the Yellowstone Plateau: (1) What are the broad-scale patterns of distribution and abundance of aspen seedlings across the subalpine plateaus of Yellowstone National Park? (2) What is the morphology and population structure -- e.g., proportions of genets (genetic individuals that developed from a single seed) and ramets (vegetative root sprouts produced by a genet) of various ages - in aspen seedling populations? (3) What are the mechanisms leading to eventual persistence or extirpation of seedling populations along an elevational gradient, particularly with respect to ungulate browsing and plant competition? (4) What is the genetic diversity and relatedness of the seedling populations along gradients of elevation and substrate?
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Margolis, H. A., and R. H. Waring. "Carbon and nitrogen allocation patterns of Douglas-fir seedlings fertilized with nitrogen in autumn. II. Field performance." Canadian Journal of Forest Research 16, no. 5 (1986): 903–9. http://dx.doi.org/10.1139/x86-161.
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October-fertilized and unfertilized 2-0 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings were outplanted the following February. Half of each planting block was seeded with grass to induce water stress during the typical summer drought. Sucrose was applied to soil around each seedling to limit availability of nitrogen to tree roots. Fertilized seedlings broke bud 9–10 days earlier, produced more shoot growth, and, as shown in later harvests, had higher relative growth rates than unfertilized seedlings. However, initial differences in growth response were due primarily to the earlier budbreak. Seedlings growing with grass had predawn water potentials of −1.5 MPa by early August; by September 3, unfertilized seedlings growing with grass were significantly more stressed than any others. Although free amino acid and total nitrogen concentrations were higher in fertilized than unfertilized seedlings when planted, they became equal by the end of one growing season. However, fertilized seedlings contained more free amino acids and nitrogen because of their greater size. Grass competition affected both seedling nitrogen and carbohydrate chemistry. After one growing season, fertilized seedlings had greater height increment, shoot growth, leaf area, relative growth rate, and production per unit nitrogen. Although autumn fertilization benefited these Douglas-fir seedlings, negative effects could result from carbohydrate depletion because of increased respiration or from frost damage because of earlier budbreak.
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Gardarin, Antoine, Françoise Coste, Marie-Hélène Wagner, and Carolyne Dürr. "How do seed and seedling traits influence germination and emergence parameters in crop species? A comparative analysis." Seed Science Research 26, no. 4 (2016): 317–31. http://dx.doi.org/10.1017/s0960258516000210.
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AbstractEarly plant establishment through seed germination and seedling emergence is a crucial process that determines seedling number, emergence time distribution and the early growth of seedlings, all of which are affected by soil climate and soil structure. In the current context of climate change, in which increasing the diversity of cultivated species is considered desirable, and new tillage practices are considerably modifying top-soil surface characteristics, we need to improve our ability to model the effects of the environment on plant establishment. Using a trait-based and model-based framework, we aimed to identify general relationships between seed and seedling traits (e.g. seed mass and lipid content, seedling diameter, base temperature) and germination and emergence model parameters (e.g. time to mid-germination, shoot elongation rate) measured for 18 genotypes belonging to 14 species. Relationships were also investigated among model parameters or traits. Germination rates were faster for species with a high base temperature and for species with seed reserves located principally in the embryo (rather than the endosperm or perisperm). During heterotrophic growth, maximal shoot length and elongation rate increased with seed dry mass. The sensitivity of seedlings to soil obstacles was negatively related to shoot diameter. Thus apart from the known effects of seed mass on seedling establishment, we found that seed reserve location, seedling shoot diameter and shape affected germination rate and emergence success. Such generic rules linking plant traits to germination and emergence parameters enhance our understanding of the determinants of environmental effects on plant establishment success.
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Detsis, Vassilis, Georgios Efthimiou, Olga Theodoropoulou, and Stavroula Siorokou. "Determination of the Environmental Factors that Affect the Growth and Survival of Greek Fir Seedlings." Land 9, no. 4 (2020): 100. http://dx.doi.org/10.3390/land9040100.
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Forests in the montane-Mediterranean zone have only recently began to be affected by wildfires, therefore the knowledge necessary for restoration projects is missing. The aim of the study was to assess the effects of factors related to seedling attributes, weather conditions and site suitability on seedling performance. The characterisation of sites was based on bedrock and soil clay content as well as pre-fire vegetation. Apical growth and survival of seedlings was monitored for four years in Parnitha National Park. The parameters of a linear mixed model were estimated using annual apical growth of seedlings surviving in the end of the study as the dependent variable and type of site, rainfall, initial seedling height and age as explanatory ones. A quantile regression model using all the data available was estimated for each year of study, taking into account only initial height and site type as well as a logistic regression model of survival. The findings indicate that the growth of Greek fir seedlings depends on May rainfall mediated by soil clay content, which in turn depends on bedrock, which is consistent with the “inverse texture hypothesis”. Sites with low soil clay content were always more beneficial for survival, which was stronger affected by summer–autumn rainfall. In both contexts, drought stress due to soil clay content fades with increasing age. Sites that were not fir dominated prior to fire proved unsuitable also for planting fir seedlings. A minor part of the observed variability could be associated with the initial height of seedlings, especially for seedlings showing high rates of apical growth.
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Stowe, Debra C., Mohammed S. Lamhamedi, and Hank A. Margolis. "Water relations, cuticular transpiration, and bud characteristics of air-slit containerized Picea glauca seedlings in response to controlled irrigation regimes." Canadian Journal of Forest Research 31, no. 12 (2001): 2200–2212. http://dx.doi.org/10.1139/x01-158.
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White spruce seedlings (Picea glauca (Moench) Voss) were grown in air-slit containers (IPL 25-350A) in a tunnel under four different irrigation regimes (IR-15%, IR-30%, IR-45%, and IR-60%, v/v; (cm H2O)3·(cm substrate)3). At the end of the first growing season the water-relation variables of the shoots were determined. Seedling morphology, the rates of cuticular transpiration and terminal bud development, as well as the number of needle primordia were also measured. Irrigation regime had no significant effect on any of the water-relation variables. Seedlings grown under the IR-15% were smaller and completed bud development more quickly than seedlings grown under IR-30%, IR-45%, and IR-60%. The formation of needle primordia was enhanced under IR-30%. Both the irrigation regime and the amount of time the detached shoots were left to transpire had a significant effect on the rate of cuticular transpiration. A comparison of the water-relation variables at the end of the first (1998) and second (1999) growing seasons showed that the younger seedlings had more negative osmotic potential at tissue saturation and greater maximum modulus of elasticity values. None of the other water-relation variables were significantly affected by seedling age, but the absolute values of all the variables were greater in the younger (1+0) seedlings.
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Durr, C., and J. Boiffin. "Sugarbeet seedling growth from germination to first leaf stage." Journal of Agricultural Science 124, no. 3 (1995): 427–35. http://dx.doi.org/10.1017/s002185960007338x.
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SUMMARYThe growth of sugarbeet (Beta vulgaris L.) seedlings was investigated under laboratory conditions in 1990 and 1991. Three phases were identified during heterotrophic growth in the dark, based on the changes in dry weight, carbon and nitrogen contents. The perispermic reserves were first transferred to the young seedling. All the components of the seedling (cotyledons, hypocotyl, radicle) began to elongate and their dry weights increased. The seedling separated from the seed at the end of this first period, 4 days after imbibition had started at 20 °C. During the second period, there was a major redistribution of material between organs, mainly from cotyledons to the hypocotyl. The different organs elongated rapidly. From the start of the third period, 6 days after sowing at 20 °C, the organs began to lose weight and gradually ceased to elongate. The dry weights of the whole seedlings and of each organ were proportional to the initial seed weights. The elongations and changes in dry weights obtained at different temperatures coincided when time was expressed as thermal time using a base temperature of 3·5 °C. The growth of the seedling after illumination depended on the heterotrophic growth duration. If emergence occurred after 100 °Cd, the relative growth rate of the seedling decreased. In field conditions, plant variability at the end of sugarbeet establishment is due not only to variations in seed weights but also to environmental conditions that control emergence delay.
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Mganilwa, Z., M. Nagata, H. Wang, and Q. Cao. "232 Determination of Cucurbitaceous Seedling Quality and Leaves Orientation for Robotic Grafting by Machine Vision." HortScience 34, no. 3 (1999): 482B—482. http://dx.doi.org/10.21273/hortsci.34.3.482b.
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Based on seedling properties and stage of growth for cucurbitaceous and solanaceous vegetables, separate robots are being marketed for each. Full automatic grafting robots are used for solanaceous vegetables like tomato and egg-plant employing ordinary splice method by making a diagonal cut through the hypocotyl of both the scion and the rootstock. However, cutting one piece of cotyledon diagonally from the rootstock does grafting of cucurbitaceous vegetables like cucumber, melon, and pumpkin. This method had the advantage of easy recovery and high survival rate of seedlings. Only semi-automatic robots are marketed for this kind of plants because a fixed cotyledon orientation is required for grafting operation. Both the scion and the rootstock are loaded manually to their corresponding feeding devices. To replace the manual loading operation, this study proposed a neural network based automatic seedling loading system. The system automatically estimates the quality and determines the cotyledon orientation of seedling for guiding the loading device of the grafting robot. As a first step toward solution, we report the development of a model for seedling quality estimation and orientation detection using image processing and neural network techniques. The model has a learning ability and can judge seedlings according to the training patterns. A seedling leaves feature extraction model of 10 characteristics was proposed and a three-layer neural network was constructed. The experimental results indicate that the seedling leaves orientation was accurately detected with an average error of 3 degrees within 360 degrees of freedom and the machine vision system could properly classify seedlings into three classes (A-good, B-fair, and C-bad) according to the training pattern.
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Krasowski, M. J., and J. N. Owens. "Morphological and physiological attributes of root systems and seedling growth in three different Picea glauca reforestation stock." Canadian Journal of Forest Research 30, no. 11 (2000): 1669–81. http://dx.doi.org/10.1139/x00-093.
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The relationship between certain morphological characteristics of white spruce (Picea glauca (Moench) Voss) planting stock (STK) and post-planting seedling performance was evaluated. Root system size at planting, its expansion, and its capacity to conduct water during the first post-planting weeks were determined. These characteristics were related to the performance of STK planted on two forest sites and measured for three growing seasons and to the performance of seedlings grown in large wooden boxes buried in the soil outdoors for one growing season (grown without competition from other vegetation). The compared STK were (i) polystyroblock grown, (ii) polystyroblock grown with chemical root pruning, and (iii) peat-board grown with mechanical root pruning. After three growing seasons on forest sites, seedlings with mechanically pruned roots grew more above ground than did seedlings from polystyroblock containers. This difference in seedling growth performance was even more significant for seedlings grown in wooden boxes. Of these, the mechanically pruned seedlings grew more not only above the ground but they also produced larger root systems by the end of the first growing season. This was despite the initially significantly smaller root systems of mechanically pruned seedlings, compared with the other two STK. Early (5-7 weeks after planting) post-planting root expansion patterns in the three STK were significantly different, with the roots of mechanically pruned seedlings growing less than the roots in the other two STK. In spite of this, pressure-probe measured hydraulic conductivity and water flux through root systems increased during the first post-planting weeks in mechanically pruned seedlings while declining or changing little in the other two STK. It was concluded that root system size at planting and its early post-planting expansion did not relate well to the root system hydraulic properties or to the post-planting seedling growth performance.
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Detsis, Vassilis, Georgios Efthimiou, Olga Theodoropoulou, and Stavroula Siorokou. "Reforestation with Abies cephalonica Loudon: a five-year study of seedling survival." Management of Environmental Quality: An International Journal 27, no. 2 (2016): 136–45. http://dx.doi.org/10.1108/meq-01-2015-0013.
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Purpose – The purpose of this paper is to establish the effects on the survival of outplanted Abies cephalonica Loudon seedlings of seedling characteristics, site characteristics and management practices. Design/methodology/approach – The study was carried out by repeatedly monitoring survival of seedlings during a five-year period as well as establishing statistical relationships with a set of variables belonging to the aforementioned categories. It took place in plots reforested after a wildfire in the Parnitha Mt. National Park, near Athens, Greece. Findings – The odds of survival were found to be affected by bedrock type, dominant vegetation, initial seedling height and use of shading implements. Artificial shading was most important during the first year, site-related characteristics gained importance with increasing age and seedling height was of relatively constant importance. Shifts in temporal patterns of mortality and damage symptoms occurrence suggest that the mechanisms causing mortality changed with increasing age. Practical implications – The use of large seedlings in reforestation projects involving A. cephalonica should be preferred. Shading improves survival but due to the high costs this technique could be reserved for unfavorable plots, e.g. on limestone. Planting A. cephalonica in marginal sites should be avoided. Originality/value – The knowledge of the performance of A. cephalonica outplanted seedlings is very limited, while the need is increasing due to the spread of wildfires in this previously unaffected habitat.
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Colombo, Ronan Carlos, Vanessa Favetta, Deived Uilian de Carvalho, Maria Aparecida da Cruz, Sergio Ruffo Roberto, and Ricardo Tadeu de Faria. "Production of desert rose seedlings in different potting media." Ornamental Horticulture 23, no. 3 (2017): 250. http://dx.doi.org/10.14295/oh.v23i3.1039.
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Over the past decade the desert rose received fame in the flower market due to its striking and sculptural forms; however, the commercial production of these species is quite recent and little is known about its crop management, including substrates recommendation. The objectives of this study were to investigate the effect of different substrates on desert rose seed germination and production of its seedlings. Experiment I: freshly harvested seeds of desert rose were sown in different substrates e.g. sand, coconut fiber, semi-composted pine bark, sand + coconut fiber, semi-composted pine bark + sand and coconut fiber + semicomposted pine bark. These substrates were evaluated to study the emergence percentage of seeds, initial growth of seedlings and seedling emergence speed index (ESI). Experiment II: desert rose from the experiment I were transferred to plastic pots filled with the same substrates as in experiment I. The pH and electrical conductivity (EC) of the substrates were noted every 30 days while the growth parameters of seedlings were recorded after 240 days. Results from experiment I showed higher germination rate and seedling growth in substrates containing semi-composted pine bark. Similarly, in experiment II, better quality seedlings were observed in substrates containing semi-composted pine bark. Thus, for desert rose seed germination and seedling growth, it is recommended to use substrates containing semi-composted pine bark.
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Zacks, Georgina, Joe Greet, Christopher J. Walsh, and Elisa Raulings. "The flooding tolerance of two critical habitat-forming wetland shrubs, Leptospermum lanigerum and Melaleuca squarrosa, at different life history stages." Australian Journal of Botany 66, no. 7 (2018): 500. http://dx.doi.org/10.1071/bt18039.
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Understanding the effect of water regime on the different life history stages of woody wetland plants is essential to managing their persistence. The common and widespread myrtaceous shrub species, Melaleuca squarrosa Donn. ex Sm. and Leptospermum lanigerum (Aiton) Sm., provide habitat for two critically endangered fauna within the Yellingbo Nature Conservation Reserve (south-eastern Australia), but are in decline putatively because of the altered flooding regimes. We, thus, tested the effects of flooding depth and duration on their seed germination and seedling establishment, and seedling growth and survival in two separate glasshouse experiments. We also compared the condition of mature plants of both species at an intermittently flooded (reference) site, and two near permanently flooded (impact) sites. Seeds of both species were able to germinate underwater, but early flooding reduced seedling establishment. Seedling growth of both species was greater in waterlogged than in well drained or inundated conditions, whereas no seedlings of either species survived &gt;8 weeks of submergence. Leptospermum lanigerum seedlings were generally more flood tolerant than were M. squarrosa seedlings. Correspondingly, crown condition of mature M. squarrosa, but not L. lanigerum, was poorer at impact than reference sites. Prolonged flooding in swamp forests is likely to (1) limit woody plant recruitment, because flooding reduces seedling establishment, growth and survival, and (2) be deleterious to the maintenance of less flood-tolerant species (e.g. M. squarrosa). Moist exposed substrate is likely to be best for promoting the recruitment of both study species, and intermittent flooding for maintaining adult M. squarrosa plants.
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Picchioni, G. A., and C. J. Graham. "Improved Orchard Establishment of Asimina triloba Seedlings on Acid Soils Supplemented with Calcium Sulfate." HortScience 32, no. 3 (1997): 475A—475. http://dx.doi.org/10.21273/hortsci.32.3.475a.
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Asimina triloba (L.) Dunal (pawpaw), a deciduous tree indigenous to the eastern U.S., is being considered as a potential new fruit crop. The difficulty in establishing transplanted pawpaw seedlings has been identified as an important research need for successful cultivation of this species. We have addressed the possible benefits of soil-applied CaSO4 in establishing pawpaw seedlings on acidic, low-Ca orchard soil. Two-year-old seedling rootstocks were planted at a spacing of 1.5 m (within rows) × 5.5 m (between rows), and trickle-irrigated (with N, P, and K) for two growing seasons. Before planting, CaSO4 was applied at rates of 0, 11, and 22 t/ha and incorporated to a depth of 15 cm. Seedling trunk cross-sectional area (TCA) growth increased with increasing CaSO4 application. After the first season, increases in TCA averaged 27% and 44% greater with CaSO4 treatments (11 and 22 t/ha, respectively), as compared to the 0 t/ha treatment. This effect was accentuated by the end of the second season. Average qualitative ratings (based on seedling vigor and appearance) were also improved with CaSO4 treatment. These findings indicate that establishment of pawpaw seedling rootstocks may be improved with Ca fertilization in orchards of low-Ca status. Additional data, including seedling dry matter accumulation, will be presented.
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Collet, Catherine, Henri Frochot, Jean-Marc Guehl, and André Ferhi. "Effect of two forest grasses differing in their growth dynamics on the water relations and the growth of Quercus petraea seedlings." Canadian Journal of Botany 74, no. 10 (1996): 1562–71. http://dx.doi.org/10.1139/b96-189.
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Interference between 1-year-old sessile oak (Quercus petraea (Mattus.) Liebl.) seedlings and two grass species (Agrostis stolonifera L. and Deschampsia cespitosa (L.) Beauv.) was evaluated during 3 years after seedling transplantation. The seedlings were grown in large containers under crossed levels of watering regimes (regular irrigation that maintained the soil at field capacity or seasonal water stress) and grass competition (with Agrostis, Deschampsia, or bare soil). After 3 years, seedling basal diameter was 2.5 times greater in the absence of competing vegetation than with one of the two grasses. Within the grass-competition treatments, diameter was 1.3 times as great for the seedlings grown in the irrigated treatments than for the seedlings grown in the water-stressed treatments and was 1.3 times greater for the seedlings grown with Agrostis than for the seedlings grown with Deschampsia. During the first 2 years, the seedlings grew much faster in the bare soil than in the weedy treatments, whatever the watering level. During the 3rd year, the seedlings in all the irrigated treatments showed similar relative growth rate values, which were much higher than those in the water-stressed treatments. Each year, soil water potential reached −2.5 MPa under the two grasses and −0.7 MPa under bare soil by the end of summer. On the contrary, competition for nutrients seemed to be low. Assessments of plant carbon isotope composition showed that the seedlings in the weedy water-stressed treatments had higher intrinsic water-use efficiency, and also suggested that the competition exerted by the two grasses occurred mainly for water. We conclude that during the first 2 years, the negative effects of the two grass species on seedling growth seemed to be largely independent of any competition for water. Conversely, during the 3rd year, the influence of the grasses on the seedlings seemed to be related only to competition for water. Keywords: root interactions, water stress, osmotic adjustment, carbon isotope discrimination, classical growth analysis.
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Timmer, V. R., and G. Armstrong. "Growth and nutrition of containerized Pinusresinosa at exponentially increasing nutrient additions." Canadian Journal of Forest Research 17, no. 7 (1987): 644–47. http://dx.doi.org/10.1139/x87-105.
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Containerized red pine (Pinusresinosa Ait.) seedlings were reared on different fertility regimes that compared conventional applications of a recommended 39 mg N per seedling as a complete nutrient solution (175 mg N•L−1) with more frequent applications of an equal, one-half, or one-quarter amount of nutrients delivered at exponentially increasing solution concentrations over the same time period. Height growth, dry matter production, and root development at the end of the greenhouse rotation was significantly greater for seedlings receiving nutrients at exponentially rather than constantly increasing rates, although shoot growth among the three exponential treatments did not differ significantly. The increased yield was attributed to improved seedling nutrition as fertilizer addition rates better matched exponential growth development and nutrient consumption of the plants. The results indicate that superior seedlings can be grown successfully at low concentrations of nutrient solution, applying only one-quarter of the fertilizer dose conventionally used for container stock production.
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Lazreg, F., L. Belabid, J. Sanchez, E. Gallego, J. A. Garrido-Cardenas, and A. Elhaitoum. "First Report of Fusarium acuminatum Causing Damping-Off Disease on Aleppo Pine in Algeria." Plant Disease 97, no. 4 (2013): 557. http://dx.doi.org/10.1094/pdis-06-12-0608-pdn.
Full textAbstract:
The Aleppo pine (Pinus halepensis Mill.) is a conifer native to the Mediterranean region. In autumn and spring of 2008 to 2009, a survey of Aleppo pine seedling diseases was carried out in three forest nurseries from the Relizane, Sidi Bel Abbes, and Tlemcen departments in northwestern Algeria. Aleppo pine seedlings were potted from the soil. In all three nurseries, 1- to 2-month old seedlings showed symptoms of damping-off disease in pre- and post-emergence (collar rot) with a disease incidence of 64, 77, and 72%, respectively. Disinfected collar segments, about 5 mm in length, were plated on PDA and petri dishes incubated at 25°C. A Fusarium sp. was consistently isolated from tissues and all isolates were morphologically identified as Fusarium acuminatum Ellis & Everh. (teleomorph: Gibberella acuminata Wollenw.) according to Fusarium keys (2). Colony growth was 43 mm after 3 days on PDA; the aerial mycelium was white, developing a brownish tinge in the center on PDA; macroconidia were formed in orange sporodochia, broadly falcate, strongly septate, 3 to 5 septa, the apical cell with an incurved elongation, distinct foot shape, 3 to 4 × 20 to 50 μm; microconidia were usually absent for isolates other than F12SS1, reniform, septate, 5 to 6 × 6 to 10 μm, in monophialides; chlamydospores were formed in chains, 6 to 13 μm. For the molecular identification, ITS regions of Fusarium isolates were amplified with the primers ITS1 and ITS4, and products were directly sequenced in both strands using the same primers ITS 1 and ITS4. Sequences were compared to known sequences deposited in the NCBI non redundant database to confirm morphological identification. An NCBI BLAST search identified isolates F12SS1, F14SS3, F30SS3, and F25SR as F. acuminatum based on 100% similarity with corresponding sequences. GenBank Accession Nos. were JX114788, JX114785, JX114782, and JX114790, respectively. Pathogenicity tests were performed to fulfill Koch's postulates. Inocula were produced by adding a 5-mm diameter plug from a 7-day-old CMA petri dish culture to a previously sterilized 500-ml flask (237.5 g sand, 12.5 g cornmeal, 80 ml SDW), shaken over 9 days, and mixed with sterile soil at 1:3 (v:v). The inocula were transferred to a 500-ml pot, and 10 Aleppo pine seeds were planted with three replicates. After 1 month, all tested isolates caused typical symptoms on seedlings and the proportion of infected seedlings per each isolate was 50, 53.33, 56.66, 60, and 63.33%, respectively. There are many reports of F. acuminatum associated to conifer seedlings in nurseries (1,3) and most of them are conflicting because in some reports this species is considered non-pathogenic or only a seed contaminant and others consider it as a pathogen. To our knowledge, F. acuminatum is a first report on the Aleppo pine in northwestern Algeria, northern Africa. It is also the first report of this fungal species affecting the Aleppo pine throughout the world, and on conifers in Africa and the Mediterranean region. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases, Systematic Mycology and Microbiology Laboratory. ARS, USDA., Bestville, Maryland, USA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , June 18, 2012. (2) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Ames, Iowa, USA, 2006. (3) D. W. Minter. Cybertruffle's Robigalia, Observations of Fungi and their Associated Organisms. Retrieved from http://www.cybertruffle.org.uk/robigalia/eng/ , June 18, 2012.
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Turner, Monica, Rebecca Reed, William Romme, and Gerald Tuskan. "Distribution, Morphology, Survival, and Genetics of Aspen (Populus tremuloides) Seedlings Following the 1988 Yellowstone Fires." UW National Parks Service Research Station Annual Reports 21 (January 1, 1997): 135–37. http://dx.doi.org/10.13001/uwnpsrc.1997.3343.
Full textAbstract:
An unexpected consequence of the 1988 Yellowstone fires was the widespread establishment of seedlings of quaking aspen (Populus tremuloides) in the burned forests, including areas outside the previous range of aspen (Kay 1993, Romme et al.1997). Although aspen is the most widely distributed tree species in North America (Powells 1965), it is relatively uncommon and localized in distribution within Yellowstone National Park (Despain 1991). Most aspen stands in Yellowstone are found in the lower elevation landscapes in the northern portion of the park, and the species was absent -- prior to 1988 -- across most of the high plateaus that dominate the southern and central park area. Aspen in the Rocky Mountain region reproduces primarily by means of vegetative root sprouting. Although viable seeds are regularly produced, establishment of seedlings in the wild is apparently a rare event due to the limited tolerance of aspen seedlings for desiccation or competition (e.g., Pearson 1914, McDonough 1985). In the immediate aftermath of the 1988 Yellowstone fires there was a brief "window of opportunity" for aspen seedling establishment, as a result of abundant aspen seed production, moist weather conditions in spring and summer, and bare mineral soil and reduced plant competition within extensive burned areas (Jelinski and Cheliak 1992, Romme et al. 1997). We initiated this 3-year study in 1996 to address four questions about the aspen seedlings now growing in burned areas across the Yellowstone Plateau: (1) What are the broad-scale patterns of distribution and abundance of aspen seedlings across the subalpine plateaus of Yellowstone National Park? (2) What is the morphology and population structure -- e.g., proportions of genets (genetic individuals that developed from a single seed) and ramets (vegetative root sprouts produced by a genet) of various ages -- in aspen seedling populations? (3) What are the mechanisms leading to eventual persistence or extirpation of seedling populations along an elevational gradient, particularly with respect to ungulate browsing and plant competition? (4) What is the genetic diversity and relatedness of the seedling populations along gradients of elevation and substrate? We completed our sampling for questions 2 and 4 in 1996 (see our 1996 annual report for details). In 1997 we continued our annual sampling related to questions 1 and 3.
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Turner, Monica, Rebecca Reed, William Romme, and Gerald Tuskan. "Distribution, Morphology, Survival, and Genetics of Aspen (Populus tremuloides) Seedlings Following the 1988 Yellowstone Fires." UW National Parks Service Research Station Annual Reports 22 (January 1, 1998): 53–55. http://dx.doi.org/10.13001/uwnpsrc.1998.3365.
Full textAbstract:
An unexpected consequence of the 1988 Yellowstone fires was the widespread establishment of seedlings of quaking aspen (Populus tremuloides) in the burned forests, including areas outside the previous range of aspen (Kay 1993, Romme et al. 1997). Although aspen is the most widely distributed tree species in North America (Fowells 1965), it is relatively uncommon and localized in distribution within Yellowstone National Park (Despain 1991). Most aspen stands in Yellowstone are found in the lower elevation landscapes in the northern portion of the park, and the species was absent -- prior to 1988 -- across most of the high plateaus that dominate the southern and central park area. Aspen in the Rocky Mountain region reproduces primarily by means of vegetative root sprouting. Although viable seeds are regularly produced, establishment of seedlings in the wild is apparently a rare event due to the limited tolerance of aspen seedlings for desiccation or competition (e.g., Pearson 1914, McDonough 1985). In the immediate aftermath of the 1988 Yellowstone fires, there was a brief "window of opportunity" for aspen seedling establishment, as a result of abundant aspen seed production, moist weather conditions in spring and summer, and bare mineral soil and reduced plant competition within extensive burned areas (Jelinski and Cheliak 1992, Romme et al. 1997). We initiated this 3-year study in 1996 to address four questions about the aspen seedlings now growing in burned areas across the Yellowstone Plateau: (1) What are the broad-scale patterns of distribution and abundance of aspen seedlings across the subalpine plateaus of Yellowstone National Park? (2) What is the morphology and population structure -- e.g., proportions of genets (genetic individuals that developed from a single seed) and ramets (vegetative root sprouts produced by a genet) of various ages -- in aspen seedling populations? (3) What are the mechanisms leading to eventual persistence or extirpation of seedling populations along an elevational gradient, particularly with respect to ungulate browsing and plant competition? (4) What is the genetic diversity and relatedness of the seedling populations along gradients of elevation and substrate? We completed our sampling for questions 2 and 4 in 1996 (see our 1996 annual report for details). In 1997 and again in 1998 we continued our annual sampling related to questions 1 and 3.
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U R, RESHMA, and SIMI S. "A correlation study of pre-sowing treatments, sowing positions and age of stones after extraction from fruit on germination of mango." Journal of AgriSearch 8, no. 2 (2021): 99–107. http://dx.doi.org/10.21921/jas.v8i2.7291.
Full textAbstract:
The present study was undertaken to assess the correlation relationship between various pre-soaking treatments, sowing positions and age of stone on germination and vigour of mango seedlings. Mango stones of different age groups viz., freshly extracted stones, 10 and 20 days after extraction of pulp were soaked in aqueous solutions of GA3 (100 and 200 ppm), KNO3 (1 and 2 ppm), cow dung slurry, water and control (without treatments) for 24 hours and were sown in flat and stalk end up method. The correlation coefficients indicate the presence of inherent association between various characters under study. The study revealed that the seedling vigour index –I had very high positive and very dependable relationship with germination percentage (r=0.988**) and seedling length (r=0.974**) whereas seedling vigour index-II had very high positive, significant correlation and very dependable relationship with seedling length (0.931**) in case of stalk end up method over the flat method of sowing.
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Hossa, Keila Regina, José Walter Pedroza Carneiro, Terezinha Aparecida Guedes, and Alessandro Lucca Braccini. "Stevia rebaudiana (Bert) Bertoni: influence of osmotic stress and seed priming on seed germination under laboratory conditions." Acta Scientiarum. Agronomy 39, no. 3 (2017): 379. http://dx.doi.org/10.4025/actasciagron.v39i3.32951.
Full textAbstract:
The foremost factor necessary for plant growers cultivating large acreages of Stevia rebaudiana (Bert) Bertoni is the production of qualitative bedding plants. The objective of this study was to evaluate the influence of osmotic-priming on the uniformity of seed germination. First, we evaluated the percentage of normal seedlings from two seed samples harvested in 2011 and 2012. The seeds harvested in 2012 produced 71.4% normal seedlings and thus they were used in the next experiments. The seeds were subjected to osmotic stress using five concentrations of polyethylene glycol (PEG-6000) at -0.2, -0.4, -0.6, -0.8, and -1.0 MPa in contrast with distilled water. Based on these first results, only -0.8 and -1.0 MPa were evaluated in the third experiment. The seeds were immersed in both concentrations of polyethylene glycol (PEG-6000) for imbibing at 20ºC for four, five, six, and seven days. Thereafter, we evaluated the time to the first normal seedling (Ti), time to the last normal seedling (Tf), percentage normal seedlings at the initial time (Pi) and percentage of normal seedlings at the end of every treatment (Pf). Osmotic priming increased the percentage of normal seedlings of the Stevia rebaudiana and reduced the time to the first and last germination events.