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1
Saka, Kamel. "REGENERATION OF COTTON (GOSSYPIUM HIRSUTUM L.) CALLUS PROTOPLASTS TO MACROCALLI." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275376.
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Idso, Keith Edward 1969. "The recovery of physiological processes following irrigation of water-stressed extra long-staple cotton." Thesis, The University of Arizona, 1992. http://hdl.handle.net/10150/278091.
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In the southwestern United States, rising costs and limited availability of water have lead to irrigation scheduling based on plant stress indicators in an effort to conserve water. This research was conducted to better define the recovery rates of transpiration, stomatal resistance, and leaf water potential in field grown extra long staple cotton (Gossypium barbadense cv. Pima S-6) following varied durations of water stress. Three water stress treatments were maintained by scheduling irrigations at different Crop Water Stress Index (CWSI) values. Plants irrigated at 0.19 and 0.68 CWSI units needed 72 hours for plant water potential to recover, while plants irrigated at 0.41 CWSI units needed only 24 hours. Water stress had a smaller effect on the recoveries of stomatal resistance and transpiration. Stomatal resistance recovered within 24 hours for all plants regardless of water treatment. Transpiration recovered within 24 hours for plants irrigated at 0.19 CWSI units, and within 48 hours for plants irrigated at 0.41 and 0.68 CWSI units.
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Bernardes, Alexandre Aparecido [UNESP]. "Identificação de doenças em folhas vegetais da cultura de algodão." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/98670.
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bernardes_aa_me_sjrp.pdf: 1061316 bytes, checksum: 626147b162746c848edf2737162a678b (MD5)A manifestação de patógenos nas plantações é a maior causadora de prejuízos nos mais diversos cultivares, podendo ocasionar o aumento dos preços e a perda da qualidade dos produtos cultivados. O quanto antes for identificada a doença, mais cedo é realizado o seu controle através de agrotóxicos, tendendo, dessa forma, a diminuir a sua proliferação e, consequentemente, evitando maiores danos. No entanto, muitas vezes, a inspeção visual dos sintomas apresentados pela ocorrência de patógenos em uma folha de planta, não é considerada o suficiente para avaliar e identificar o tipo de doença que está causando a lesão, sendo necessário, para o diagnóstico da doença, uma análise mais detalhada por um agrônomo ou por meio de um exame laboratorial a partir da amostra da doença. Neste contexto, este trabalho realizou a classificação automática de doenças do algodoeiro, a partir da extração de características dos sintomas foliares apresentados em imagens digitais. Utilizou-se para este processo, a energia da transformada wavelet para extração de características das imagens e para realizar a classificação foi utilizado a Máquina de Vetor de Suporte (MVS). Ao percorrer o sistema final de classificação, uma imagem pode ser classificada entre cinco tipos de diagnósticos diferentes, como sendo “Sadia” (SA), lesionada com as doenças Ramulária (RA), Mancha Angular (MA) e Mancha de Ascochyta (AS), ou identificada pertencente a nenhuma das classes
The expression of pathogens in the plantations is the leading cause of damage in several cultivars, which may cause higher prices and loss of quality of crops. The sooner the disease is identified, the sooner it is done through its control of pesticides, tending thus to reduce their proliferation and thus avoiding further damage. However, often the visual inspection of the symptoms presented by the occurrence of pathogens in a leaf, is not considered enough to assess and identify the type of disease that is causing the lesion, being necessary for the diagnosis of disease, a more detailed analysis by an agronomist or through a laboratory test sample from the disease. In this context, this paper carried the automatic classification of diseases of cotton, from the feature extraction of leaf symptoms presented in digital images. It was used for this process, the energy of wavelet transform to extract features from images and to perform the classification, we used the Support Vector Machine (SVM). By walking through the final system of classification, an image can be classified in five types of different diagnoses, as being Healthy (SA), with the injured Ramularia diseases (RA), Bacterial Blight (MA) and Ascochyta Blight (AS) or belonging to any of the identified classes
4
Soares, Leonardo Cirilo da Silva. "Efeito de reguladores de crescimento (via tratamento de sementes e foliar) no desenvolvimento e na produtividade da cultura de algodão." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-10022011-164159/.
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Com o objetivo geral de verificar o efeito do uso de reguladores de crescimento, via tratamento de sementes e foliar, sobre o desenvolvimento e a produtividade da cultura de algodão foram desenvolvidos cinco experimentos durante os anos de 2009 e 2010 (quatro desenvolvidos em Piracicaba, SP e o quinto em Pedra Preta, MT) com os seguintes objetivos específicos: (Experimento 1): verificar o efeito de dois reguladores de crescimento (cloreto de mepiquat associado ou não a ciclanilida) e doses (0,00+0,00; 1,60+0,40; 4,50+0,00 e 4,50+1,13 g de cloreto de mepiquat + ciclanilida por kg de sementes) sobre o desenvolvimento de diferentes cultivares de algodão (FMT-523, FMT-701, NuOpal, FM-993 e FM-910); (Experimento 2): verificar o efeito de diferentes reguladores de crescimento (cloreto de mepiquat associado ou não a ciclanilida) e doses (0,00+0,00; 0,75+0,19; 1,50+0,00; 1,50+0,38; 2,25+0,56; 3,00+0,00; 3,00+0,75; 3,75+0,94; 4,50+0,00 e 4,50+1,13 g de cloreto de mepiquat + ciclanilida por kg de sementes), aplicado via tratamento de sementes, sobre o desenvolvimento da cultura de algodão; (Experimento 3): verificar o efeito do uso do regulador de crescimento cloreto de mepiquat via tratamento de sementes (doses de 0,0 e 4,5 g de cloreto de mepiquat por kg de sementes), combinado com diferentes doses foliares (doses de 0, 63, 126 e 189 g.ha-1 de cloreto de mepiquat aplicadas em duas épocas, sendo a primeira aplicação: [1] em V4 - aplicação precoce - e [2] em B1 - aplicação padrão), no desenvolvimento e na produtividade da cultura de algodão; (Experimento 4): verificar o efeito do uso do regulador de crescimento cloreto de mepiquat via tratamento de sementes (doses de 0,0 e 4,5 g de cloreto de mepiquat por kg de sementes), combinado com diferentes doses foliares (0, 125, 250, 375 e 500 g.ha-1 de cloreto de mepiquat), na produtividade da cultura de algodão; e (Experimento 5): verificar o efeito de diferentes reguladores de crescimento (cloreto de mepiquat associado ou não a ciclanilida) e doses (0,00+0,00; 0,75+0,19; 1,13+0,00; 1,50+0,38; 2,25+0,00; 2,25+0,56; 3,00+0,75; 3,38+0,00; 3,75+0,94; 4,50+0,00 e 4,50+1,13 g de cloreto de mepiquat + ciclanilida por kg de sementes), aplicados via tratamento de sementes, no desenvolvimento da cultura de algodão. De acordo com os resultados obtidos, conclui-se que o uso do cloreto de mepiquat, via tratamento de sementes e foliar, interfere retardando o desenvolvimento e reduzindo o crescimento e a produtividade da cultura de algodão, e que a ciclanilida, via tratamento de sementes, potencializa o efeito do cloreto de mepiquat.With the general purpose of verifying the growth regulators (applied by seed treatment and foliar) effect on cotton crop development and productivity five experiments were carried out during 2009 and 2010 (four in Piracicaba, State of São Paulo, and one in Pedra Preta, State of Mato Grosso) with the following specific objectives: (Experiment 1): verify the effect of two growth regulators (mepiquat chloride in association with cyclanilide) and doses (0.00+0.00, 1.60+0.40, 4.50+0.00 and 4.50+1.13 g of mepiquat chloride + cyclanilide per kg of seeds) on the development of different cultivars of cotton (FMT-523, FMT-701, NuOpal, FM-993 e FM-910); (Experiment 2): verify the effect of different growth regulators (mepiquat chloride in association with cyclanilide) and doses (0.00+0.00, 0.75+0.19, 1.50+0.00, 1.50+0.38, 2.25+0.56, 3.00+0.00, 3.00+0.75, 3.75+0.94, 4.50+0.00 and 4.50+1.13 g of mepiquat chloride + cyclanilide per kg of seeds), applied by seed treatment, on the crop cotton development; (Experiment 3): verify the effect of mepiquat chloride (growth regulator) by seed treatment (doses of 0.0 and 4.5 g of mepiquat chloride per kg of seeds), associated to different foliar doses (0, 63, 126 and 189 g.ha-1 of mepiquat chloride applied in two periods, being the first application: [1] in V4 - precocious application - and [2] in B1 - standard application), on the development and productivity of cotton crop; (Experiment 4): verify the effect of mepiquat chloride (growth regulator) by seed treatment (doses of 0.0 and 4.5 g of mepiquat chloride per kg of seeds), associated to different foliar doses (0, 125, 250, 375 and 500 g.ha-1 of mepiquat chloride), on the cotton crop productivity; and (Experiment 5): verify the effect of different growth regulators (mepiquat chloride in association with cyclanilide) and doses (0.00+0.00, 0.75+0.19, 1.13+0.00; 1.50+0.38, 2.25+0.00, 2.25+0.56, 3.00+0.75, 3.38+0.00, 3.75+0.94, 4.50+0.00 and 4.50+1.13 g of mepiquat chloride + cyclanilide per kg of seeds), applied by seed treatment, on the cotton crop development. According to the results, we conclude that the use of mepiquat chloride, by seed treatment and foliar, slows the development and reduces the growth and yield of cotton crop, and the cyclanilide, applied by seed treatment, enhances the negative effect of chloride mepiquat.
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Bernardes, Alexandre Aparecido. "Identificação de doenças em folhas vegetais da cultura de algodão /." São José do Rio Preto : [s.n.], 2011. http://hdl.handle.net/11449/98670.
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Orientador: Aledir Silveira PereiraBanca: Adilson Gonzaga
Banca: Rodrigo Capobianco Guido
Resumo: A manifestação de patógenos nas plantações é a maior causadora de prejuízos nos mais diversos cultivares, podendo ocasionar o aumento dos preços e a perda da qualidade dos produtos cultivados. O quanto antes for identificada a doença, mais cedo é realizado o seu controle através de agrotóxicos, tendendo, dessa forma, a diminuir a sua proliferação e, consequentemente, evitando maiores danos. No entanto, muitas vezes, a inspeção visual dos sintomas apresentados pela ocorrência de patógenos em uma folha de planta, não é considerada o suficiente para avaliar e identificar o tipo de doença que está causando a lesão, sendo necessário, para o diagnóstico da doença, uma análise mais detalhada por um agrônomo ou por meio de um exame laboratorial a partir da amostra da doença. Neste contexto, este trabalho realizou a classificação automática de doenças do algodoeiro, a partir da extração de características dos sintomas foliares apresentados em imagens digitais. Utilizou-se para este processo, a energia da transformada wavelet para extração de características das imagens e para realizar a classificação foi utilizado a Máquina de Vetor de Suporte (MVS). Ao percorrer o sistema final de classificação, uma imagem pode ser classificada entre cinco tipos de diagnósticos diferentes, como sendo "Sadia" (SA), lesionada com as doenças Ramulária (RA), Mancha Angular (MA) e Mancha de Ascochyta (AS), ou identificada pertencente a nenhuma das classes
Abstract: The expression of pathogens in the plantations is the leading cause of damage in several cultivars, which may cause higher prices and loss of quality of crops. The sooner the disease is identified, the sooner it is done through its control of pesticides, tending thus to reduce their proliferation and thus avoiding further damage. However, often the visual inspection of the symptoms presented by the occurrence of pathogens in a leaf, is not considered enough to assess and identify the type of disease that is causing the lesion, being necessary for the diagnosis of disease, a more detailed analysis by an agronomist or through a laboratory test sample from the disease. In this context, this paper carried the automatic classification of diseases of cotton, from the feature extraction of leaf symptoms presented in digital images. It was used for this process, the energy of wavelet transform to extract features from images and to perform the classification, we used the Support Vector Machine (SVM). By walking through the final system of classification, an image can be classified in five types of different diagnoses, as being "Healthy" (SA), with the injured Ramularia diseases (RA), Bacterial Blight (MA) and Ascochyta Blight (AS) or belonging to any of the identified classes
Mestre
6
Alejos, Marcos. "Transient Expression of BABY BOOM, WUSCHEL, and SHOOT MERISTEMLESS from Virus-Based Vectors in Cotton Explants: Can We Accelerate Somatic Embryogenesis to Improve Transformation Efficiency?" Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1609070/.
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Upland cotton (Gossypium hirsutum L.) is the world's most prominent fiber crop. Cotton transformation is labor intensive and time consuming, taking 12 to 18 months for rooted T0 plants. One rate limiting step is the necessary production of somatic embryos. In other recalcitrant species, ectopic expression of three genes were shown to promote somatic embryogenesis: WUSCHEL (WUS), SHOOT MERISTEMLESS (STM), and BABY BOOM (BBM). WUS is responsible for maintaining stem-cell fate in shoot and floral meristems. STM is needed to establish and maintain shoot meristems. STM and WUS have similar functions but work in different pathways; overexpression of both together converts somatic cells to meristematic and embryogenic fate. BBM encodes an AP2/ERF transcription factor that is expressed during embryogenesis and ectopic expression of BBM reprograms vegetative tissues to embryonic growth. In prior studies, these genes were constitutively expressed, and cultures did not progress beyond embryogenesis because the embryogenic signal was not turned off. In our study, we set out to use these genes to increase the efficiency of cotton transformation and decrease the time it takes to regenerate a plant. A disarmed cotton leaf crumple virus (dCLCrV) vector delivers WUS, STM, or BBM into cotton tissue cultures through Agrobacterium tumefaciens infection. We propose that virus delivery of embryo-inducing genes is a better approach for transformation because A) inserts more than 800 nucleotides are unstable, and will spontaneously inactivate, B) virus DNA can migrate through plasmodesmata to cells around the infected cell, creating a gradient of embryonic potential, C) the virus DNA does not pass through the germ line and the seed will not contain virus. We propose this method of inducing embryogenesis will facilitate the stable transformation of cotton and will be beneficial to the cotton industry. Ectopic expression of AtBBM, AtSTM, and AtWUS GrWUS:meGFP from a constitutive CaMV 35S promoter produced plants with phenotypes similar to those described in previous studies overexpressing AtBBM, indicating that the AtBBM gene was functional. The cotton cotyledon infiltration of the pART27 constructs showed transformed cells in Coker 312 by GFP localization in the nucleus. Although GFP was detected, no visible embryos appeared from the cotyledon. Cotyledons infiltrated with Agrobacterium harboring overexpression vectors withered and aborted after ~2 weeks. The virus-based vector in tissue culture failed to increase transformation efficiency, resulting in no embryos. The combination of hormone concentration showed no contribution to increasing the transformation efficiency.
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Wilson, F. D., and H. M. Flint. "Host Plant Resistance." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/203923.
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Steger, A. J., J. C. Silvertooth, and P. W. Brown. "Timing Initial Post-plant Irrigation Based upon Plant-Water Status." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/210292.
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A two year study was conducted to determine the optimum timing of the initial post plant irrigation using leaf water potential (LWP) measurements. A short - season Upland cotton (Gossvpium hirsutum L.), variety DPL 20, was planted on 19 April 1993 and 15 April 1994 at the Marana Agricultural Center on a Pima clay loam (Typic Torrifluvent) soil. Treatments, designated Tl , 72, and T3, were such that the initial post plant irrigation would be applied when the midday LWP of the uppermost, fully- developed leaf exposed to full sunlight measured -15, -19, and -23 bars, respectively. All treatments received the same irrigation regime following the initial post plant irrigation. Basic plant measurements, including plant height, mainstem node number, fruit retention, number of nodes above the uppermost white bloom, fresh bloom count within a 166 -ft1 area, and percent canopy cover, were taken weekly from each plot. Soil -water data was collected at 10 inch depth increments, to a depth of 60 in. , from access tubes located in each experimental unit. Yields were 1112, 1095, and 977 lbs lint/acre in 1993 and 1082, 1035, and 964 lbs lint /acre in 1994 for T1, 72, and T3, respectively. Yields were reduced when the midday LWP was allowed to fall below -19 bars, however, reduction was significant (P 5 0.05) only in 1993. At the time of the initial post plant irrigation for each treatment, approximately 83, 62, and 32 % of the total plant available water was present in the upper 60 in. of the soil profile for Ti, 72, and T3, respectively.
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Silvertooth, J. C., E. R. Norton, and S. W. Stedman. "Plant Population Evaluation for Upland Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/209589.
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Norton, E. R., J. C. Silvertooth, and S. W. Stedman. "Plant Population Evaluation for Upland Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/210251.
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Plant population management is an important aspect of cotton production. Recommendations for optimum plant densities range from 25,000 - 45,000 plants per acre (ppa). A study was conducted in Pinal county in 1994 to evaluate the recommendations already given. Plant densities for this study ranged from approximately 18,000 - 65,000. Yields increased with populations of 18,000, 28,000, and 39,000 ppa. For populations of 43,000 and 65,000 ppa a corresponding decrease in yield from 39,000 ppa was observed. This study serves to reconfirm the recommendations for optimum plant densities.
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Wilson, F. D., and H. M. Flint. "Host Plant Resistance." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219754.
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The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers.Cotton breeding stocks were evaluated for resistance to pink bollworm. Resistance is being transferred into improved agronomic stocks.
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Hood, L. R. "Multiple Plant Growth Regulator Use on Short Staple Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1993. http://hdl.handle.net/10150/209534.
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A field trial was initiated during the 1992 growing season to evaluate the activity of Cytokin and Piz applied alone or in combination to short staple cotton. The Cytokin treatment significantly increased lint yield over the other treatments. There were no statistically significant differences between the non-treated check and any other treatment. The Cytokin treatment increased lint yield an average of 81 pounds over the check plots. Fruit retention remained high throughout the season, indicating that Pix would not normally have been needed.
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Hood, L. R. "Multiple Plant Growth Regulator Use on Short Staple Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/210271.
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A field trial was conducted during the 1992 & 1993 growing seasons to evaluate the activity of Cytokin and Pic applied alone or in combination to short staple cotton. The Cytokin treatment significantly increased tint yield over the other treatments in 1992. There were no statistically significant seed cotton differences between the non - treated check and any treatment in 1993. Fruit retention remained high throughout 1992 and very high throughout the 1993 season. Under high fruiting conditions, use of a plant growth regulator would not normally be recommended.
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Silvertooth, J. C., Paul W. Brown, Steven H. Husman, and Ed Martin. "Timing the First Post-plant Irrigation." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001. http://hdl.handle.net/10150/146992.
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Mekala, Diwakar Karthik. "Screening upland cotton for resistance to cotton fleahopper (Heteroptera: Miridae)." Thesis, Texas A&M University, 2004. http://hdl.handle.net/1969.1/1071.
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Cotton (Gossypium hirsutum L.) crop maturity is delayed by cotton fleahopper (Pseudatomoscelis seriatus Reuter) (fleahopper) feeding on early-season fruit forms which increases vulnerability to late-season pests such as Helicoverpa zea (Boddie) and Heliothis virescens (Fabricius). The objectives of this research were to evaluate methods of screening for resistance to fleahopper and to screen selected genotypes. Six fleahoppers were caged on plants in the insectary for 72 h. Numbers of live fleahoppers and percent square damage were determined 48 h following the removal of fleahoppers. Fleahopper numbers and percent square set were determined on randomly selected plants of 16 genotypes when grown under field conditions in 2002 and 2003. Across multiple sampling dates, the number of fleahoppers per plant was higher (p=0.05) in G. arboreum and Pilose (G. hirsutum), but no consistent differences were observed among the remaining 15 genotypes which represented several germplasm pools across the United States. Field and no-choice feeding tests suggested that Pilose, Lankart 142, Suregrow 747, and Stoneville 474 were more resistant hairy-leaf genotypes and not different (p=0.05) in resistance than the smooth-leaf genotypes, Deltapine 50 and TAM 96WD-69s. Pin-head, match-head, and one-third grown squares were removed from plants and placed on agar in petri-plates. Four fleahoppers were released per plate and allowed to feed for 48 h. Fleahopper damage, brown areas along the anthers and/or brown and shrunken pollen sacs was most evident in pin-head sized squares.
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Kittock, David L., Roger A. Selley, and B. Brooks Taylor. "Comparison of Normal and Short Pima Cotton Cultivars at Different Plant Populations." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/203928.
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Clark, L. J., and E. W. Carpenter. "Plant Growth Regulator Studies at the Safford Agricultural Center, 1993." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/209604.
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Clark, L. J., and E. W. Carpenter. "Plant Growth Regulator Studies at the Safford Agricultural Center, 1994." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/210270.
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Methanol, Cytokin and PGR IV plant growth regulators were tested on long and short staple cotton on the Safford Agricultural Center in 1994. It was a follow up study on Methanol and Cytokin and a first time look at PGR IV.
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Husman, Stephen H., William B. McCloskey, and Kyrene White. "Plant Population Effects on Twin Line Cotton Production." College of Agriculture, University of Arizona (Tucson, AZ), 2004. http://hdl.handle.net/10150/198131.
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Three experiments at the University of Arizona Maricopa and Marana Agricultural Centers in 2002 and 2003 measured effect of plant populations on the yield of cotton planted in the twin seed-line per bed configuration. In 2002 at the Maricopa Ag. Center, the plant populations were 52800, 69200, 82800 and 96200 plants per acre (PPA) for Stoneville 4892BR and 54800, 70800, 90500 and 104500 PPA for AG3601, respectively. The two lowest plant populations which were in the range of common commercial plant densities resulted in the greatest lint yields for both varieties (an average of 1708 and 1287 lb lint/A for ST4892BR and AG3601, respectively) but there was a significant linear decrease in yield with increasing plant population. In 2003, the cotton variety Delta Pine 449BR was planted and the population densities were 22000, 29000, 36000, 46000, 51000, 61000, and 64,000 PPA at the Marana Ag. Center and 24000, 34000, 41000, 56000, 63000, 71000, and 86,000 PPA at the Maricopa Ag. Center. Cotton yield did not vary significantly as a function of population density at Maricopa and averaged 1526 lb lint/A. At Marana there was a slight trend of increasing yield with increasing plant densities with the three highest plant populations averaging 1385 lb lint/A. In the experiments with ST4892BR and AG3601 at Maricopa in 2002 and with DP449BR in 2003 there was a linear decrease in fiber micronaire with increasing density but this effect of density on micronaire was not observed possibly because plant populations Marana were lower than in the other experiments.
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Day, A. D., B. B. Taylor, I. K. Pepper, and M. M. Minnich. "Plant Growth and Seed Cotton Yield of Upland Cotton Fertilized with Liquid Sewage Sludge." College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/204452.
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Seedling emergence, plant establishment, plant height, and seed cotton yield for cotton grown with liquid sewage sludge were similar to the seedling emergence, plant establishment, plant height, and seed cotton yield for cotton grown with recommended inorganic fertilizer. High applications of liquid sewage sludge decreased water penetration in Pima clay loam soil.
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Hofmann, Wallace C., Peter T. Else, and Ramadjita Tabo. "The Effects of Three Plant Growth Substances on DPL 90." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/204039.
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Olsen, Mary W. "Cotton (Texas) Root Rot." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2009. http://hdl.handle.net/10150/144800.
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4 pp.Cotton root rot commonly causes a sudden wilt and death of susceptible plants in summer months but may also cause a slow decline, especially at cooler temperatures. So, positive identification of disease by an experienced person is essential. This publication addresses the symptoms, environmental conditions, disease, prevention and control methods, sampling, identifying susceptible plants and the tolerant and immune plants of cotton root rot.
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Fisher, W. D., and E. J. Pegelow. "Heat Units and Stages of Plant Development." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219831.
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Martinez-Diaz, Gerardo 1959. "Allelopathy of purple nutsedge (Cyperus rotundus L.) on cotton (Gossypium)." Diss., The University of Arizona, 1997. http://hdl.handle.net/10150/282406.
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The effects of extracts from purple nutsedge tubers were determined on the germination, growth, root leakage, water status, and photosynthesis of an Upland cotton, DPL 5415, and a Pima cotton, Pima S-7. Tubers extracts inhibited secondary root growth of seedlings more than primary root growth. At 500 ppmw, primary root growth was inhibited 44 percent whereas inhibition of secondary root growth was 64 percent. Non-polar extracts were more inhibitory to growth than polar extracts. Cotton plants grown in soil treated with hexane extracts of tubers containing non-polar allelopathic substances also lost electrolytes from their roots indicating an effect on root function. The effects on root function resulted in perturbations to the capacity of the plants to maintain efficient water status. At 250 ppmw of the hexane extract, the plant water potential, the leaf water content, and the leaf osmotic potential decreased from -0.7 to -1.3 MPa, from 89 to 79 percent, and from -0.8 to -1.0 MPa, respectively. In addition, the photosynthetic capacity of cotton was decreased 50 percent in both cotton cultivars in the second and third day after transplanting to soil treated with 62 ppmw of the hexane extracts. Leaf dehydration to below 70 percent relative water content and a reduction of quantum yield was detected in DPL 5415 at 125 ppmw of the hexane extracts. However, Pima S-7 was capable of tolerating higher levels of dehydration and did not show the reduction of quantum yield. Leaf expansion and epicotyl growth were also inhibited by 30 and 37 percent, respectively, by the hexane extracts at 250 ppmw. Purple nutsedge tubers released volatile substances that inhibited growth when trapped and tested on cotton seedlings, and caused root leakage. GC analyses showed that both the hexane extracts of purple nutsedge tubers and the volatile compounds released from the tubers contained substances with retention times that are characteristic of sesquiterpenes. These results demonstrate that purple nutsedge tubers contain allelopathic substances capable of inhibiting the growth of cotton by interfering with membranes of root cells, disrupting water status, and affecting photosynthesis.
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Husman, S. H., and J. C. Silvertooth. "Plant Population Effects on Pima S-6 Lint Yield." College of Agriculture, University of Arizona (Tucson, AZ), 1992. http://hdl.handle.net/10150/208640.
Full textAbstract:
A replicated field study was conducted at the Maricopa Agricultural Center in 1991 to investigate the effect of plant population density on Pima S-6 lint yield. Treatments ranged from a low of 10,465 plants per acre to a high of 65,000 plants per acre. There were no significant yield differences observed with populations between 17,000 plants per acre and 65,000 plants per acre. Significant yield decreases occurred when populations were reduced below 17,000 plants per acre.
26
Silvertooth, J. C., J. C. Navarro, E. R. Norton, and A. Galadima. "Soil and Plant Recovery of Labeled Fertilizer Nitrogen in Irrigated Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 2001. http://hdl.handle.net/10150/211318.
Full textAbstract:
Proper timing of fertilizer N applications in relation to crop uptake can serve to improve fertilizer efficiency in irrigated cotton. Earlier research has identified an optimum application window extending from the formation of first pinhead squares to peak bloom, which corresponds well with maximum crop uptake and utilization. Field experiments were conducted at the University of Arizona Marana Agricultural Center (Grabe clay loam soil) utilizing sidedress applications of ammonium sulfate with 5-atom % 15-N at pinhead square, early bloom, and peak bloom at a rate of 56 kg N/ha. The objective was to compare relative efficiencies in terms of fertilizer N uptake and recovery among these three times of application. Results indicate that all treatments averaged approximately 80% total fertilizer N recovery. Of the fertilizer N that was recovered, approximately 40 % was taken up by the plants and 60 % recovered in the soil, primarily in the top 60 cm of the soil profile.
27
Clark, L. J., and E. W. Carpenter. "Plant Growth Regulator/Foliar Nutrient Studies at the Safford Agricultural Center, 1995." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/210773.
Full textAbstract:
Methanol, Cytokin, Cytoplex, PGR IV and Foli-Zyme plant growth regulators were tested on long and short staple cotton on the Safford Agricultural Center in 1995. It was a follow up study on Methanol, Cytokin and PGR IV and a first time look at Cytoplex and Foli-Zyme. Trends toward increased lint yield were seen with Cytokin and Cytoplex with the other treatments yielding near or below the untreated check Some increase in maturity was seen on the short staple plots by all of the treatments. Some differences in HVI data were also observed.
28
Rethwisch, Michael D., Greg Hurtado, and Rosario Hurtado. "Comparison of Various Plant Growth Regulators on Pima S-7 Cotton Yields." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/210772.
Full textAbstract:
All plant growth regulators and nutritional products applied to Pima S-7 cotton during bloom economically increased lint yields, with increases ranging from 80 - 261 lbs. /acre. Greatest increase was noted with Boll-Set Plus, a product that contains raised levels of calcium and zinc. Cytokin and Boll -Set Plus significantly increased yields at one location. A lint yield increase of approximately 40 lbs/acre was noted when Tech-Flo Alpha was added to Cytokin. A single application of Foliar Triggrr resulted in equal yields as two applications of the Cytokin plus Tech-Flo Alpha.
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Hofmann, W. C., and P. T. Else. "An Evaluation of the BioHumaNeticsᴿ Plant Growth Substance." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219738.
Full textAbstract:
The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers.Plant growth substances and fertilizers from BioHumaNeticsᴿ were evaluated under field conditions on DPL 61 at the University of Arizona Maricopa Agricultural Center in 1985. Treatments included: 1)standard fertilization recommended for the farm, 2)no added fertilizers and 3)a treatment schedule prescribed by BioHumaNetics. No statistically significant differences were detected.
30
Hofmann, W., J. Stroehlein, C. Michaud, P. Else, and J. Dahlberg. "Drip Irrigated Cotton Responses to Water Level, Varieties and Plant Population." College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/204484.
Full textAbstract:
Three cotton cultivars (DPL 41, 90 and 775) were planted at 3 seeding rates (5, 10 and 20 lbs/A). These variables were evaluated under 5 drip irrigation treatments, which included 23.3, 25.7, 28.0, 30.7 and 31.4 inches of water applied over the growing season. There were 3" of precipitation over the growing season. Only the lowest irrigation level showed significantly reduced yields. DPL 90 had superior yields as compared to DPL 775, with DPL 41 having an intermediate response. The 10 lb/a seeding rate resulted in higher yields as compared to the other 2 rates.
31
Stroehlein, J. L., W. C. Hofmann, C. Michaud, E. P. Scheuring, and T. C. Knowles. "Drip Irrigated Cotton Responses to Fertilizer Levels, Varieties and Plant Population." College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/204485.
Full textAbstract:
Three cotton cultivars (DPL 41, 90 and 775) were planted at 3 seeding rates (5, 10 and 20 lbs/A). These variables were evaluated under 5 fertilizer treatments which included increasing nitrogen levels and one treatment with nitrogen (N), phosphorus (P), potassium (K) and zinc (Zn). Residual soil N was high and variable and no clear response to applied N was found, although generally higher yields were found with the high N rate. The plots receiving P, K and Zn yielded less than plots receiving an equal amount of N. Increased seeding rates significantly increased yields which was probably an effect of early weed competition. Delta Pine 90 produced significantly more than 41 which was greater than 775. Petiole and soil nitrate values reflected the high and variable available soil N.
32
Butler, G. D. Jr, D. L. Coudriet, and T. J. Henneberry. "Effect of Plant-Derived Oils on Sweetpotato Whitefly on Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1991. http://hdl.handle.net/10150/208378.
Full textAbstract:
Cottonseed oil applied to cotton repelled sweetpotato whitefly (SPW) adults up to 8 days in greenhouse tests. Soybean oil (5 %) resulted in reduced numbers of adults and numbers of eggs laid. SPW egg hatch was reduced 84% after treatment with 10% crude cottonseed oil solutions as measured by the number of first instar larval emergence. Also, numbers of whitefly larvae were reduced 99, 91 and 83% on day 6 following treatment with 10% cottonseed oil, S and 1.5% soybean oil, respectively. Negligible plant leaf phytotoxicity occurred from the plant-derived oil treatments.
33
Nelson, J. M., and G. L. Hart. "Effect of Plant Water Status on Defoliation of Pima Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/210257.
Full textAbstract:
A study was conducted at the University of Arizona Maricopa Agricultural Center, Maricopa, AZ in 1994 to determine the influence of plant water status at the time of defoliation on effectiveness of defoliants and yield of Pima cotton. Several irrigation termination dates were used to achieve different levels of plant water stress at the time defoliants were applied. A single application of defoliants did not provide adequate defoliation under the conditions of this test. The earliest irrigation termination date resulted in the highest defoliation percentage. High CWSI values at the time defoliants were applied were related to the highest defoliation percentages, but were not necessarily related to satisfactory defoliation. The CWSI appears to have limited value as a guide to determine when to defoliate Pima cotton.
34
Nurol, Bahadir. "Social Consequences Of Privatization: Sumerbank Eregli Cotton Plant Case." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/3/12609244/index.pdf.
Full textAbstract:
The thesis attempts to provide a critical evaluation of the social consequences of privatization. It is mainly based upon a field study conducted in Eregli, an industrial town in Central Anatolia, and evaluates workers&rsquoattitudes towards the effects of privatization on their lives. For that purpose, firstly, social development paradigm is highlighted since its current premise is the necessity of privatization
secondly, Turkish Experience of the State Economic Enterprises is taken into consideration
and lastly, providing a case study on the privatization of Sü
merbank Eregli Cotton Plant, social consequences of privatization are examined more closely. Thus, it will also be possible to point out concretely that privatization is a social phenomenon in addition to its economic side. The main conclusion of this thesis is that a large scale privatization without taking into consideration social returns damaged the welfare of communities in which it experienced.
35
Abdul-Razak, Mubarak Ali. "INFLUENCE OF GROWTH REGULATORS AND FERTILIZERS ON COTTON YIELD AND PLANT BEHAVIOR." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/184196.
Full textAbstract:
The effect of the plant regulator Mepiquat chloride (PIXᵀᴹ) (1,1-dimethyl-piperidinium chloride), in the early flowering stage, and combinations with soil and foliar application of fertilizers was investigated through seven field experiments conducted in 1982 and 1983 at three University of Arizona experimental locations. Three upland cotton cultivars (Gossypium hirsutum L.), 'Deltapine 55', '61' and '62' were used. Cotton yield, boll properties, fiber properties, leaf chlorophyll content, plant height, plant partitioning and maturity were investigated. Petiole nitrate, leaf area index (LAI) and LAI interrelationship with yield were also included in this study. The use of PIX resulted in an increase in seed cotton yield and boll weight in one of the experiments, while fiber properties did not show any significant response to either PIX or fertilizers. PIX, however, had the tendency to enhance maturity by about 1 week. Use of PIX reduced plant height in all tested cultivars at all locations. The reduction in plant height ranged from 7 to 28% depending on the cultivar, location and the amount of PIX applied. The chlorophyll a and b content of leaves increased significantly as a result of PIX application in two of four tests, while their ratio decreased. Leaf area index between treatments were not significantly different except at one sampling date. In a regression study, however, yield was found to be related positively to LAI when soil and foliar application of fertilizer were added, while it was negative when PIX was applied. Neither PIX nor BALANCEᵀᴹ (1:18:18:1) application affected plant partitioning nor petiole nitrate concentration at most of the sampling dates.
36
Bariola, Louis A. "Using Plant Growth Regulators to Control Pink Bollworms and Boll Weevils." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219781.
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Guinn, Gene, and Donald L. Brummett. "Irrigation and Nitrogen Effects on Plant Hormones, Boll Retention, and Growth of Fruiting Branches." College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/204460.
Full textAbstract:
An experiment was conducted in Phoenix in 1986 to determine effects of water and N deficits on ABA and IAA concentrations in young bolls and their abscission zones in relation to boll retention, and to determine the effects of N on growth of fruiting branches through the season. Water deficit decreased boll retention, decreased the concentration of free IAA in bolls and their abscission zones, and increased ABA in bolls and abscission zones. But, the concentration of ester IAA increased with water deficit (in contrast to free IAA). Because ester IAA resists degradation during stress, it may facilitate recovery when stress is relieved and some of it is converted to free IAA. N-deficiency symptoms were mild and did not appear early in the season. N had no effect on the ABA and IAA contents of bolls and their abscission zones, and had only a small effect on growth of fruiting branches. The N test is to be repeated in 1987 when N deficiency should be more severe.
38
Steger, A. J., J. C. Silvertooth, and P. W. Brown. "Use of Leaf Water Potentials to Determine Timing of Initial Post-Plant Irrigation." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/209615.
Full textAbstract:
Presumably, from a physiological standpoint, early season water stress should be avoided to ensure early fruit initiation, good fruit retention, and optimum yield potential of cotton (Gossypium spp.). This study was conducted to determine the optimum timing of the initial post plant irrigation and the long term effect of postponement on subsequent plant growth patterns, fruit retention, and yield. A short - season Upland variety, (G. hirsutum L.), DPL 20, was planted on 19 April in Marana, AZ, elevation 1970 ft. , on a Pima clay loam (Typic Torrifluvent) soil. Plots (experimental units) consisted of eight 40 in. rows and extended the full length of the irrigation run (600 ft.). Experimental design was a randomized complete block with four replications. Initial post - plant irrigations, designated T1 , 72, and T3, were applied when the midday leaf water potential (ψ) of the uppermost, fully- developed leaf reached -15, -19, and -23 bars, respectively. All treatments received the same irrigation regime following the initial post plant irrigation. Basic plant measurements were taken weekly from each experimental unit. These included plant height, number of mainstem nodes, location of first fruiting branch, fruit retention, number of nodes above the uppermost white bloom, bloom count within a 166 ft² area, and percent canopy cover. Soil -water data at seven 25 cm depth increments was collected from a total of 36 access tubes located within the field study, with three tubes per plot. Lint yields (lb. lint /acre) were 1112, 1095, and 977 for T1 , 72, and T3, respectively. Yields were significantly lower when the initial post plant irrigation was applied after ψ, dropped below -19 bars, confirming the results of a previous study conducted in 1992. Throughout the growing season, height - node ratios (HNR) of T1 and 72 plants were at or above the upper threshold established for DPL 20, while T3 HNR remained close to the expected baseline. Fruit retention was low for all three treatments due to season -long insect pressure from lygus bug. The low fruit retention data reflects the effects of high HNR. Future work will include efforts to separate changes in ψ due to day-to-day climatic variations from those caused by soil -water depletion. A second objective will be to incorporate the data obtained from the neutron moisture meter probe into the study results in an effort to better describe the complete soil-plant-atmosphere continuum as affected by the various treatment regimes employed in this study.
39
Hofmann, W. C., J. L. Stroehlein, B. B. Taylor, C. Michaud, and P. T. Else. "Response of Surface Drip Irrigated Cotton to Water Levels, Varieties and Plant Populations." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219748.
Full textAbstract:
The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers.A drip irrigation trial was conducted at Eloy, Arizona to investigate optimal irrigation levels for cotton. Five irrigation levels (23.6, 26.7, 29.9, 32.8 and 33.8 acre inches) were applied to DPL 41, DPL 90 and DPL 774. The varieties were planted at 5, 10, and 20 pounds/acre. There were no statistical differences in yield in the 3 wetter irrigation treatments. Both of the drier water levels produced significantly lower yields. Significant differences were also detected in the response of the varieties and populations.
40
Rethwisch, Michael D., Nathan Rovey, Nathan Heeringa, and Aron Quist. "Comparison of Early Season and Mid-Season Applied Plant Growth Regulators on DPL 5415 Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/210758.
Full textAbstract:
Several plant growth regulators were applied to DPL 5415 cotton to evaluate effectiveness on cotton lint yield. Growth regulators applied in small amounts over multiple applications early in the growing season reduced yields compared with the check while a single application applied at full-bloom slightly increased lint yields. High night time temperatures from late July into early September were detrimental for cotton production. Increased squaring of early season applications compared with the check may have resulted in reduced yields due to increased stress from temperatures and/or nutrient availability. Increased stress in the early treated (more fruit) plots may have had greater fruit abscission.
41
Nelson, J. M., and Gary Hart. "Effect of Plant Nitrogen Status on Defoliation of Short-Season Upland Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1992. http://hdl.handle.net/10150/208668.
Full textAbstract:
Field studies have been conducted over a four year period at the Maricopa Agricultural Center to determine the influence of nitrogen (N) fertility level on the effectiveness of chemical defoliants for short- season cotton production. Excessive N resulted in dense foliage and cotton that was difficult to defoliate. When plants were deficient in N from mid-season to termination, defoliants were very effective, but lint yields were reduced. The effectiveness of defoliants decreased as the petiole NO₃-N content increased. The optimum fertility program for short-season cotton is one that provides sufficient N during the season to produce maximum lint yields, but allows the crop to become deficient in N at the end of the season, prior to chemical defoliation.
42
Nelson, J. M., P. G. Bartels, and G. Hart. "Effect of Plant Water Status on Defoliation and Yield of Pima Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1993. http://hdl.handle.net/10150/209531.
Full textAbstract:
A field study was conducted at the Maricopa Agricultural Center to determine the influence of plant water status at the time of defoliation on the effectiveness of defoliants and yield of Pima cotton. Irrigation termination dates of 4 and 18 September and 2 October were used to achieve different levels of plant water stress at the time defoliants were applied (16 October). Irrigation termination dates tested had no significant effect on lint yield or the effectiveness of defoliants. All irrigation termination dates resulted in defoliation of 80% or higher using a single application of defoliants. At the time of defoliation, CWSI values ranged front 0.59 to 0.80 and plant water potential from -2.0 to -2.9 MPa for the three irrigation termination treatments.
43
Nelson, J. M., and G. L. Hart. "Effect of Plant Water Status on Defoliation and Yield of Pima Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/209596.
Full textAbstract:
A field study was conducted at the Maricopa Agricultural Center to determine the influence of plant water status at the time of defoliation on the effectiveness of defoliants and the yield of Pima cotton. Irrigation termination dates of 3 and 20 September and 8 October were used to achieve different levels of plant water stress at the time defoliants were applied (26 October). A single application of defoliants was not adequate to defoliate the cotton under the conditions of this test. The 3 September irrigation termination date resulted in the highest percentage of defoliation (63 %). CWSI and plant water content (RWC) measurements indicated that the irrigation termination treatments resulted in large differences in plant water stress at defoliation time. There was a significant increase in the percent defoliation as the CWSI values increased from 0.54 to 0.99.
44
Briggs, R. E., and C. A. Ledbetter. "Effects of the Experimental Plant Regulator XE-1019 on Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219752.
Full textAbstract:
The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers.The experimental plant regulator XE-1019, a product of Chevron Chemical Company, was applied to short staple cotton at the University of Arizona Marana Agricultural Center in 1985. Plant height was modified by the chemical due to greatly shortened internode length. The 1.0 lb. a.i. XE-1019 per acre rate applied before bloom yielded significantly less than the other treatments at final harvest. Data collected from eight harvests through the season from sub-plots resulted in significant yield differences from the second through the sixth harvest dates.
45
Delaney, Dennis Patrick Monks C. Dale. "Management of Ultra Narrow Row Cotton." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Summer/Dissertations/DELANEY_DENNIS_10.pdf.
Full text
46
Olsen, Mary. "Cotton (Texas) Root Rot." College of Agriculture, University of Arizona (Tucson, AZ), 2015. http://hdl.handle.net/10150/346609.
Full textAbstract:
Revised 02/2015; Originally published: 2000.The most important disease of woody dicotyledonous plants in Arizona is Phymatotrichopsis root rot (Cotton or Texas root rot) caused by a unique and widely distributed soil-borne fungus, Phymatotrichopsis omnivora. The fungus is indigenous to the alkaline, low-organic matter soils of the southwestern United States and central and northern Mexico.
47
Briggs, R. E., J. M. Nelson, and G. Hart. "Plant Growth Regulator Research on Upland Cotton at the Maricopa and Marana Agricultural Centers in 1989." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/208295.
Full textAbstract:
Field tests were conducted at the Maricopa and Marana Agricultural Centers to evaluate the effectiveness of growth regulators on Deltapine 90 cotton. With full season management, the check treatment yielded as well as any of the growth regulator treatments at both locations.
48
Hofmann, Wallace C., David L. Kittock, and Joel Malcuit. "Field Treatment of Cotton Seed During Planting with an Undeficed Plant Growth Regulator." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/204032.
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49
Prewitt, Sarah F. "Phylogenetic and Functional Characterization of Cotton (Gossypium hirsutum) CENTRORADIALIS/TERMINAL FLOWER1/SELF-PRUNING Genes." Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc1062895/.
Full textAbstract:
Plant architecture is an important agronomic trait driven by meristematic activities. Indeterminate meristems set repeating phytomers while determinate meristems produce terminal structures. The centroradialis/terminal flower1/self pruning (CETS) gene family modulates architecture by controlling determinate and indeterminate growth. Cotton (G. hirsutum) is naturally a photoperiodic perennial cultivated as a day-neutral annual. Management of this fiber crop is complicated by continued vegetative growth and asynchronous fruit set. Here, cotton CETS genes are phylogenetically and functionally characterized. We identified eight CETS genes in diploid cotton (G. raimondii and G. arboreum) and sixteen in tetraploid G. hirsutum that grouped within the three generally accepted CETS clades: flowering locus T (FT)-like, terminal flower1/self pruning (TFL1/SP)-like, and mother of FT and TFL1 (MFT)-like. Over-expression of single flower truss (GhSFT), the ortholog to Arabidopsis FT, accelerates the onset of flowering in Arabidopsis Col-0. In mutant rescue analysis, this gene driven by its native promoter rescues the ft-10 late flowering phenotype. GhSFT upstream sequence was used to drive expression of the uidA reporter gene. As anticipated, GUS accumulated in the vasculature of Arabidopsis leaves. Cotton has five TFL1-like genes, all of which delay flowering when ectopically expressed in Arabidopsis; the strongest phenotypes fail to produce functional flowers. Three of these genes, GhSP, GhTFL1-L2, and GhBFT-L2, rescue the early flowering tfl1-14 mutant phenotype. GhSPpro:uidA promoted GUS activity specifically in plant meristems; whereas, other GhTFL1-like promoters predominately drove GUS activities in plant vascular tissues. Finally, analysis of Gossypium CETS promoter sequences predicted that GhSFT, GhSP, GhTFL1-L1, GhTFL1-L2 and GhBFT-L2 are regulated by transcription factors involved in shoot and flowering development. Analysis of cotton's two MFT homologs indicated that neither gene functions to control shoot architecture. Our results emphasize the functional conservation of members of this gene family in flowering plants and also suggest this family as targets during artificial selection of domestication.
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Nelson, J. M., and G. Hart. "Effect of Plant Nitrogen Status on Effectiveness of Defoliants for Short Season Cotton Production." College of Agriculture, University of Arizona (Tucson, AZ), 1991. http://hdl.handle.net/10150/208323.
Full textAbstract:
A field study was conducted at the Maricopa Agricultural Center to determine the influence of nitrogen fertility level on the effectiveness of defoliants for short-season cotton production. Increasing the nitrogen fertility level from 30 to 130 lbs N/A decreased lint yields from 3.2 to 26 bales /A. High residual soil N favored the use of a low N fertility rate. Defoliation treatments were most effective at the 30 lbs. N/A fertility level. Increasing the application rate of Dropp from 0.2 to 0.4 lbs. a.i./A increased the percent defoliation. There was a significant linear decrease in the effectiveness of defoliants as the petiole NO₃-N content increased from 300 to 7000 ppm.