Academic literature on the topic 'Pterocarpus angolensi – Seedlings – Growth'

This study explores the effects of different levels of urea and folivert (composite fertilizer) on seedlings growth and chlorophyll concentration of Albizia zygia, Blighia welwitschii, Lophira alata and Pterocarpus soyauxii. The rate of fertilizer application per 5.87kg pot with topsoil was 3, 6, and 9g of both urea and composite fertilizer and a control (top soil only) and it was a complete randomized design. Results indicated that plants treated with 3g of urea produced the highest number of leaves in Albizia zygia seedlings only while 9g of composite fertilizer had the best growth performance in all the other growth variables. Albizia zygia and Blighia welwitschii, seedlings had the best results in soil treated with 6g of composite fertilizer, while Lophira alata and Pterocarpus soyauxii seedlings showed best growth in soils treated with 9g of composite fertilizers for all other parameters. Seedlings of species supplied with 9g of urea gave poorest growth performance. Low root/shoot ratios were obtained for all seedlings except for those of Albizia zygia treated with 6 and 9g of urea that had root/shoot ratios greater than 1.0. The effect of fertilizers on chlorophyll concentration was significantly different only for L. alata (P=0.05). This study therefore brings to light the need to fertilize timber tree seedlings in order to improve on their early growth performances in the field and high doses of nitrogen should be discourage.

Nursery is a process in producing good quality seedlings. Seedling quality is determined by physical-physiological quality including woody stem, health, height, diameter, number of leaves, leaf color and compactness of media. The quality of angsana seedlings in this study was observed using some growth media, lateral root cutting, and cow’s urine addition with various concentration and liquid organic fertilizer for 13 weeks. The study was conducted in a completely randomized design (CRD) in split plot with 3 growth mediums, 10 combinations of root-cutting and fertilizing treatment using 9 seedlings per treatment. Parameters observed during this study were seedling height (cm), seedling diameter (mm), total dry weight (g), shoot - root ratio (RPA) and compactness of roots. The results showed the media contain mixture of soil and manure (M2) with root-cutting treatment, addition of 20% cow urine and 5% EM4 (A2) was the best treatment for angsana seedlings with average value of 46.25 cm plant height, 6.09 mm diameter, 7.77 g total dry weight, shoot root ratio 1.89 and compactness of roots including the compact category.Key word : cow’s urine, lateral roots cutting, Pterocarpus indicus Willd., seedling quality.

Coastal wetland plant communities are strongly structured by water depth and salinity. Rising sea level will cause changes in the hydro-period, surface water salinity and salt-water intrusion in coastal areas, which will reduce the distribution of forests in these areas. We studied the dynamics of a Pterocarpus officinalis stand in Puerto Rico over a 9-y period. We observed differences in plant growth, recruitment and mortality across a salinity gradient within a 1-ha plot. In areas of high salinity, recruitment, juvenile density and growth rates of juveniles and adults were lower. The detrimental effect of salinity was also observed in a growth experiment; seedlings in 5‰ and 10‰ salinity treatments had higher mortality, slower growth and less above- and below-ground biomass than control seedlings (0‰). In addition, an increase from 0 to 1‰ in salinity resulted in approximately 50% less nodulation in seedlings. Low recruitment in high salinity areas and lack of recruitment in adjacent grasslands will further reduce the distribution of this forest type. Although some ecosystems can respond to changing conditions by migration to more favourable areas, this is not the case with P. officinalis, and thus, restoration efforts are needed to re-establish this species where it occurred historically.

Acacia nilotica which is a plants of the genus Acacia which is known as one of the invasive genera. A. nilotica is very invasive due to several advantages it has such as very large seed production, seed dispersal far enough by wildlife, young plants to grow very fast and are resistant to drought and fire. Some invasive acacia species can act as nurse plants for native plants, which increases the photosynthetic efficiency of native plants, and protects native species from extreme temperatures. Therefore, it is important to know the chance of recolonizing native plants in areas that are invaded by foreign species, by looking at the performance of plants seedlings under A. nilotica stands. This study aims to determine the potential of A. nilotica invasive plants as nurse plants for local plants in East Timor. The stages in this research are the preparation of tools and materials, seeding of target species, selection of A. nilotica stands as a nurse plants, selection of healthy target species seedlings to be planted, planting of target species seedlings under A. nilotica stands, observing survival ability and species growth target. An analysis of the survival ability of the seedlings was carried out using the Kaplan-Meier survival curve. The results of this study are the angsana seedlings and kabesak in this study experienced many deaths, external factors such as high-temperature factors due to the long dry season suspected to be the cause. A. nilotica shade does not affect the survival of the angsana and kabesak seedlings, allelopathy produced by A. nilotica plants accompanied by a drought in a long period of time causes the plants is unable to act as nurse plants for kabesak and angsana plants.

Pterocarpus santalinus is a highly valued medium-sized leguminous endemic tree with a restricted range in the southern Eastern Ghats deciduous forests. The enumeration in four 1ha plots has yielded a total of 878 Red Sanders tree individuals (≥30cm girth at breast height - gbh) with a range of 165–246 individuals per ha and 9–51 individuals per 0.01ha. The size class structure revealed that the majority of individuals occurred in lower gbh classes with 364 individuals (39.5%) in 30–50 cm gbh class and 420 individuals (45.6%) in 51–70 cm gbh class, while in the higher gbh class (71–90 cm gbh) only 129 individuals (14%) and seven individuals in >90cm gbh class were recorded. Overall the population structure indicated a low ratio change in lower gbh classes suggesting a stable population. A higher percentage of life stages in recruitment stage like seedlings and saplings than trees was observed and the feature of re-sprouting from roots after fire damage was also recorded. A bottleneck progress from regenerating trees to adult trees was noticed, may be due to slow growth of the species. High stem density and presence of individuals in all the regenerating and reproductive classes suggest that Red Sanders is tolerant to mild disturbance. But the drastic reduction in the density in higher gbh class reflects the concern for recruitment in future as it may affect the seed output due to loss of reproductively fit mature trees.

Pterocarpus angolensis, a leguminous tree native to the dry woodlands of Southern Africa, provides valuable timber, but is threatened by land conversion and overharvesting while showing limited natural regeneration. Nitrogen-fixing root nodule symbionts that could improve establishment of young seedlings have not yet been described. Therefore, we investigated the ability of P. angolensis to form nodules with a diverse range of rhizobia. In drought-prone areas under climate change with higher temperatures, inoculants that are heat-tolerant and adapted to these conditions are likely to be of advantage. Sources of bacterial isolates were roots of P. angolensis from nurseries in the Kavango region, other shrubs from this area growing near Pterocarpus such as Indigofera rautanenii, Desmodium barbatum, Chamaecrista sp., or shrubs from drought-prone areas in Namaqualand (Wiborgia monoptera, Leobordea digitata) or Kalahari (Indigofera alternans). Only slight protrusions were observed on P. angolensis roots, from which a non-nodulating Microbacterium sp. was isolated. Rhizobia that were isolated from nodules of other shrubs were affiliated to Bradyrhizobium ripae WR4T, Bradyrhizobium spp. (WR23/WR74/WR93/WR96), or Ensifer/Mesorhizobium (WR41/WR52). As many plant growth-promoting rhizobacteria (PGPR), nodule isolates produced siderophores and solubilized phosphate. Among them, only the Bradyrhizobium strains nodulated P. angolensis under controlled conditions in the laboratory. Isolates were further characterized by multilocus sequence analysis and were found to be distant from known Bradyrhizobium species. Among additional reference species tested for nodulation on P. angolensis, Bradyrhizobium vignae 7-2T and Bradyrhizobium namibiense 5-10T from the Kavango region of Namibia as well as Bradyrhizobium elkanii LMG6234T and Bradyrhizobium yuanmingense LMG21728T induced nitrogen-fixing nodules, while Bradyrhizobium diazoefficiens USDA110T and Bradyrhizobium tropiciagri SEMIA6148T did not. This suggests a broad microsymbiont range from Bradyrhizobium japonicum and B. elkanii lineages. Phylogenetic analysis of nodC genes indicated that nodulating bradyrhizobia did not belong to a specific symbiovar. Also, for I. rautanenii and Wiborgia, nodule isolates B. ripae WR4T or Mesorhizobium sp. WR52, respectively, were authenticated. Characterization of symbionts inducing effective root nodules in P. angolensis and other shrubs from Subsahara Africa (SSA) give insights in their symbiotic partners for the first time and might help in future to develop bioinoculants for young seedlings in nurseries, and for reforestation efforts in Southern Africa.

African kino tree (Pterocarpus erinaceus) plants are widely used species in afforestation programs but germination of seed and rate of seedling growth are major drawback. This study was therefore carried out to compare the effect of decomposed organic matter on the seedling growth rate of Pterocarpus erinaceus. The experiment was conducted in the screen house of Forestry Research Institute of Nigeria for a period of six months. Seedlings of P. erinaceus were subjected to four treatments. Decomposed kitchen waste (KW), decomposed fruit waste (FrW), decomposed fish waste (FW) and decomposed White leadtree (Leucaena leucocephala (LL)) leaves and control (CN). The experiment was laid out using a Completely Randomized Design. Each treatment was replicated seven times. Results showed that there was significant difference (P≤0.05) among the height of P. erinaceus seedlings subjected to different fertilizer applications. The mean seedlings height ranged from 11.55 to 18.34 cm with the highest mean height from seedlings subjected to LL while seedlings without fertilizer application had the least mean height. There was no significant difference (P≤0.05) among the collar diameter of P. erinaceus seedlings subjected to different fertilizer applications. The mean seedlings collar diameter ranged from 1.27 to 1.94 mm with the highest mean collar diameter from seedlings subjected to FW while seedlings without fertilizer application (CN) had the least mean collar diameter. Results also indicated no significant difference (P≤0.05) among the number of leaves of P. erinaceus seedlings subjected to different fertilizer applications. The mean seedlings number of leaves ranged from 12 to 16 with the highest mean number of leaves from seedlings subjected to LL, KW and FW while seedlings without fertilizer application had the least mean number of leaves. It is recommended that application of decomposed organic matter for proper growth of Pterocarpus erinaceus seedlings should be encouraged and properly disseminated to farmers.

Thesis (PhD)--Stellenbosch University, 2004.
ENGLISH ABSTRACT:Six experiments, five in the glasshouse and one in the field near Nelspruit, were carried out to ascertain the effect of factors related to shoot die-back, and of water treatments on the growth and physiological responses of Pterocarpus angolensis seedlings. The study was undertaken to broaden the knowledge and understanding of the phenomenon of shoot die-back in order to enhance our ability to regenerate the species. The following experiments were carried out (a) Assessment of biomass accumulation; anatomical characteristics of the shoot apical meristem; foliar, stem and root concentration of micro- and macronutrients associated with each phenophase, (b) Effect of seedling age and seed source on the occurrence of shoot die-back under field conditions; (c) Water treatment effects on ChI. afluorescence traits of£'. angolensis seedlings obtained by assessing the fluorescence yield of photosynthetic samples subjected to dark- and light-adaptation; (d) Genetic variation in shoot die-back and other traits of sixteen halfsib families of £.. angolensis from Malawi, Namibia and Zambia grown over two die-back seasons. Experiments conducted revealed the following 1. Patterns of growth observed in phenophases are indicators of seasonal changes in annual biomass allocation to the shoot and root. Phenophases such as leaf loss and stem senescence, whether shoot die-back occurs completely or not, are directly related to the decline in above-ground biomass and declined rate of increase in root biomass respectively. Leaf flush, expansion and maturation result in increased biomass accumulation whilst shoot die-back has a minimal downregulatory effect on root biomass accumulation compared to the shoot. Shoot dieback is not sudden, therefore from the first day of germination, seedlings synchronise growth and development with the occurrence of shoot die-back. 2. Phenophasic concentration of foliar N, Ca and Mg, stem Fe and Cu and root concentrations of P, K, Mg, Fe and B are associated with shoot die-back. Patterns of mineral nutrient concentration obtained in foliage and roots but to a lesser extent in the stem, may be related to nutrient remobilisation during shoot dieback. Higher relative mineral nutrient changes during leaf yellowing and shoot die-back may be an indication of the removal of significant volumes of mobile nutrients from senescing tissues. 3. The volume of the shoot apex of E. angolensis remains constant during different phenophases which points to seasonal uniformity in the size of the apical dome. Changes in phenology associated with declined growth, or shoot die-back, is revealed through declined cell number in the tunica which is a reflection of declined mitotic activity. 4. Shoot die-back occurs in all seedlings from nursery stock planted under field conditions and all seedlings of up to two years experience complete shoot dieback. Shoot die-back takes place irrespective of seed source or the age of nursery stock that is planted. Survival after the first shoot die-back is normally low. Water treatments had no significant effect on the function of PSIJ reaction centres of P. angolensis nursery seedlings. In the case of both dark- and light-adapted leaves, water treatment had no significant effect on the measured Chi. a fluorescence parameters or the calculated parameters (specific activities, phenomenological fluxes, structure-function and performance indexes and drivingforces). 5. Water treatments affect the shape of ChI. a fluorescence transients of lightadapted compared to that of dark-adapted photosynthetic samples of E. angolensis. No significant water treatment effect was obtained for extracted and technical Chi. afluorescence parameters, specific fluxes, quantum efficiencies and phenomenological fluxes. Quantum yield, relative electron transport and quantum yield limitation, de-excitation rate constants, structure-function, performance indexes and driving forces were also not significantly different across water treatments.6. Genetic variation was observed to exist among 16 halfsib families from Malawi, Namibia and Zambia. High heritabilities were obtained for shoot die-back and other traits, indicating that shoot die-back is genetically controlled. The trait is passed from parents to offspring and it is highly probable that it occurs, throughout its natural range, in all seedlings. Since shoot die-back is genetically programmed, it remains crucial to the ability of a seedling to regenerate in the following rainy season
AFRIKAANSE OPSOMMING:Ses eksperimente, vyf in die glashuis en een in die veld naby Nelspruit, is uitgevoer om die effek van faktore wat verwant is aan die terugsterwing van lote op saailinge, sowel as om die effek van waterstres op die groei en fisiologiese responsies van Pterocarpus angolensis saailinge, te ondersoek. Die studie is ondemeem om die kennis en begrip aangaande die regenerasie-dinamika van die spesies te verbeter. Die volgende eksperimente is uitgevoer: (a) Evaluering van die effek van jisiologiese veranderings op biomassa; blaar-, stam- en wortelkonsentrasies van spoor- en makro-voedingselemente, en anatomiese eienskappe van die apikale meristeem van die lote. (b) Effek van saailingouderdom en saadbron op die voorkoms van lootterugsterwing onder veldtoestande. (c) Waterbehandelingseffekte op Chi. ajluorisensie eienskappe van ,e. angolensis saailinge wat verkry is deur die jluorisensie te evalueer van fotosintesemonsters wat aan donker- en lig-adaptasies onderwerp is. (d) Genetiese variasie in loot-terugsterwing en ander groei-eienskappe van 16 halfsib families van ,e. angolensis vanaf Malawi, Namibia en Zambia wat gekweek is oor twee terugsterj-seisoene. Die eksperimente het die volgende aan die lig gebring: 1. Groeipatrone waargeneem gedurende die fenofases is indikatore van seisoenale veranderings in jaarlikse biomassa allokasies aan die loot en die wortels. Fenofases soos blaarverlies en lootafsterwing, ongeag of loot-terugsterwing volledig is of nie, is direk verwant aan die afname in bogrondse biomassa en afnemende tempo van toename in wortelbiomassa respektiewelik. Bottende blare, vergroting en rypwording van blare lei tot toenemende biomassa akkumulasie terwyl loot-terugsterwing 'n minimale afskalende effek op akkumulasie van wortelbiomassa het in vergelyking met die van die loot. Loot-terugsterwing is nie skielik, met ander woorde vanaf die eerste dag van ontkieming sinchroniseer saailinge groei en ontwikkeling met die voorkoms van loot-terugsterwing. 2. Fenofase konsentrasies van en veranderings in blaar N en Ca en loot Fe, asook veranderings in waargenome wortel N, K, Ca, Mn, Cu, Zn en B is sterk geassosieer met loot-terugsterwing. Patrone van minerale voedingselementkonsentrasies wat in blare en wortels, en in minder mate in die loot, verkry is, mag direk verwant wees aan hermobilisering van voedingselemente gedurende loot-terugsterwing. Hoe relatiewe minerale voedingselementveranderings gedurende die vergeling van blare en lootterugsterwing mag 'n indikasie wees van die verwydering van betekenisvoUe hoeveelhede mobiele nutriente vanaf sterwende weefsel. 3. Die volume van die groeipunt van r. angolensis bly konstant gedurende verskillende fenofases wat dui op seisoenale uniformiteit in die grootte van die apikale koepel. Veranderings in fenologie ge-assosieer met afnemende groei, of loot-terugsterwing, word gerejlekteer deur afnemende selgetaUe in die tunika wat dui op afnemende mitotiese aktiwiteit. 4. VoUedige loot-terugsterwing kom voor in aUe saailinge vanaf die kwekery wat in die veld geplant word tot op die ouderdom van twee iaar. Dit kom voor angeag van saadbron of ouderdom van saailinge ten tye van planting. Oorlewing na aanvanklike loot-terugsterwing is normaalweg laag. 5. Water behandelings het geen beduidende effek op die funksie van PSII reaksiesentra van r. angolensis kewekery-saailinge gehad. Vir beide donker- en lig-aangepaste blare is geen beduidende waterbehandelingseffek verkry vir waargenome ChI. a jluoresensie parameters of die berekende parameters (spes ifieke aktiwiteite, jenomenologiese jlukse, struktuur-funksie-indekse, "perjormance-indekse oj" driving forces" ). 6. Genetiese variasie tussen 16 halfsibfamilies vanaf Malawi, Namibie en Zambie is verkry vir loot-terugsterwing en ander groei-eienskappe. Dit dui op genetiese beheer van terugsterwing en dat die eienskap oorerjbaar is, en waarskynlik in die hele natuurlike verspreidingsgebied van die spesies in aUe saailinge voorkom. Aangesien loot-terugsterwing gene ties geprogrammeer is, is dit noodsaaklik vir die vermoe van die plant om in die volgende reenseisoen te regenereer.