Sokoine University of Agriculture

Seed yield and quality of Cenchrus ciliaris cv. Biloela under various agronomic practices in sub-humid eastern zone of Tanzania

Show simple item record Kizima, Jonas B. 2016-06-28T15:13:33Z 2016-06-28T15:13:33Z 2015
dc.description PhD Thesis en_US
dc.description.abstract Livestock production especially ruminants, is one of the major agricultural activities in Tanzania. Both traditional and improved livestock production depend on natural and improved forages which are inadequate due to land use pressures from other users which sometimes result in resource use conflicts. Land ownership to intensify livestock farming is shown to be one of the steps for increased livestock productivity, improved degraded grazing land and for resolving conflicts associated with land use pressures. Pasture establishment is an alternative solution to improve owned land and hence increased livestock productivity, despite inadequate availability of good quality planting material especially grass pasture seeds. Cenchrus Ciliaris cv.Biloela (buffel grass) is among those adapted promising grass species promoted for establishment for its desirable drought tolerant characteristics, Inadequacy and poor viability of the buffel grass seeds seem to be the hindrance. Available information showed that, low fertility of soils and high risks of diseases are among the major factors affecting viability of buffel grass seeds in wet season. There is also limited information on production of seeds and forage biomass of this grass in dry season under irrigation, its response to different fertilizer application rates, rows spacing, cutting heights and the overall biomass productivity under field conditions. Therefore, there was a need to conduct a study to gain a practical experience on how to compromise facts on seed quality and forage biomass production under field conditions in sub humid agro-ecological zone of Tanzania. The main objective of the study was to evaluate the effects of various agronomic practices on seed yield and quality of Cenchrus ciliaris cv. Biloela in the sub-humid eastern zone of Tanzania. In order to achieve the main objective of the study, a field survey of three pasture seed farms was done, followed by field trials at Magadu dairy farm of Sokoine university of Agriculture to evaluate different agronomic practices including fertilizer levels and row spacing under two cutting heights on how they affect seed yield, quality and forage biomass production in wet and dry season. The three seed farms were Mazimbu in Morogoro, Vikuge pasture seed production farm in Kibaha and TALIRI, Tanga. A laboratory experiment was conducted to assess viability status of sampled Cenchrus ciliaris seeds from the visited farms and those produced from the field trial. Soil samples were also taken from visited farms so as to assess current fertility status of these seed farms. The results showed that spikelet germination percentage was 8.33% for Mazimbu, 0.25% for Vikuge and 1.83% for Tanga farms. Total soil Nitrogen was observed to be at very low to low levels i.e. 0.08%, 0.13% and 0.12% for Vikuge, Tanga and Mazimbu farms, respectively. From this study it could be concluded that old age sward produced low quality seeds in terms of viability, and this could be further exacerbated by low soil fertility. In order to improve an understanding of grass seed production, additional studies on fertilizer rates, irrigation during dry season, rows spacing, cutting height on how they affect seed yield and quality were conducted in the similar agro-ecological zone. For specific objective 2 and 3, study two was conducted at Sokoine University of Agriculture farm to assess the effects of different levels of Nitrogen and Phosphorus 0 KgN/ha 0KgP/ha, 40KgN/ha 20KgP/ha, 60KgN/ha 30KgN/ha P abbreviated as (0N 0P, 40N 20P, 60N 30P) , row spacing (25, 75 and 100 cm) under two cutting heights (15 cm and ground cut) under rain fed and irrigation in wet and dry seasons on seed yield and vegetation characteristics of Cenchrus ciliaris cv.Biloela. The study was done in two consecutive years 2012 and 2013 (March – June and June- September) for long rains and dry seasons, respectively. It was observed that, seed yields were higher at higher rates of nitrogen and phosphorus at ground cutting (77.5 kg/ha) than at 15 cm cutting height (56.7 kg/ha) with a trend of decreased seed yields in the second year (77.5 to 38.4 kg/ha) and (56.7 to 35.5 kg/ha) at the same levels of nitrogen and phosphorus. Row spacing of 100cm showed slightly higher seed yield (70 kg/ha) as compared to other two row spacing (25 cm and 75cm) that gave 67.2 and 69.3 kg/ha, respectively. Higher seed yields were observed in dry than wet season for two consecutive years under all cutting heights (66.7 and 37.8 kg/ha 15 cm cutting for dry and wet season, respectively). Higher levels of nitrogen and phosphorus yielded significantly (p<0.05) higher forage biomass (13.2 and 11.1 t DM/ha) from 15cm and ground cutting respectively as compared to 10.0 and 8.6 t DM/ha for low level of nitrogen and phosphorus rates. High plant density at 25 cm row spacing yielded higher biomass (12.2 t DM/ha) than low plant density at 100 cm row spacing (11.4 t DM/ha). It was concluded that, ground cutting could be beneficial management practice for rhizomatous grass so as to obtain higher seed yields since it allows healthier ground tillers from rhizomes than profuse aerial tillers produced at higher cutting heights. Irrigation during dry season was the best option for Cenchrus ciliaris cv. Biloela seed production when row spacings of 75 cm and 100 cm are used at ground cutting height with proper rates of nitrogen and phosphorus. However, strategies for bird scaring during dry period (offseason) were highly emphasized from blooming stage to seed maturity to maximize seed yield. Study two (specific objective three) was done to investigate the effect of fertilizer levels and row spacing under two cutting heights on seed quality of Cenchrus ciliaris cv. Biloela in wet and dry season using irrigation. In this study, four parameters of seed quality namely; caryopsis index, spikelet germination, seed colour and physical grain qualities (good and damaged) were assessed for first and second harvest. The findings showed significantly high (p≤ 0.05) caryopsis index for seeds produced in dry and wet season (37.9 and 24.3%) respectively. The interaction of fertilizer levels within seasons marked a clear variation on caryopsis index and germination potential in dry season seeds for seeds of first harvest than second harvest. The colour of seeds produced during the wet season indicated a vivid sign of fungal infection. The age of vegetation also significantly (p<0.05) affected the germination of seeds in both year one and year two from 20.4 to 30.0% and 12.9 to 22.8%, respectively. It was also observed that, old age vegetation produced low viable seeds than younger vegetation. Viability improved with time of storage, however only six months were tested. These results suggest that dry season and higher rates of nitrogen and phosphorus fertilizer be taken into consideration to improve production of quality grass pasture seeds, however proper fertilizer rates depends on soil fertility status of the site. Harvest time had a significant (p < 0.05) effect on quality of batches of seeds produced. The first harvested seeds were significantly (p < 0.05) higher in viability than second harvest thus were good for commercial purposes. For specific objective 4, the third study was conducted to evaluate profitability of both seed and forage biomass production of buffel grass (Cenchrus ciliaris cv.Biloela) based on irrigation in dry season and wet season under different levels of Nitrogen and phosphorus using Urea and Triple Super Phosphate (TSP) fertilizers. The study was carried out at Magadu Dairy farm of Sokoine University of Agriculture, Morogoro, Tanzania. Two seasons (wet and dry) were involved with three treatments:- without fertilizer (0KgN/ha 0KgP/ha), combined fertilizers (40KgN/ha 20 KgP/ha) and (60KgN/ha 30KgP/ha). All the fixed and variable costs were recorded and computed for cost benefit analysis during the trial and supplemented with secondary information from other input suppliers and farms. The results of this study showed that higher level of fertilizer significantly (p<0.05) led into more seed yield and biomass than when lower levels were applied. Economically, break even level was reached in wet season for revenues from both seeds and forage in year 1 and 2. However, only one level of fertilizer (60KgN/ha 30KgP/ha) was profitable by (TZS 81,011.75) during the year 1 in dry season due to costs incurred for irrigation and planting materials. The profit in dry season was realized in second year. Trend of seed and forage production was profitable in year two for both seasons as no costs were incurred for establishment for perennial species where planting materials costs are only incurred in first year. It was learnt that it was profitable to produce forage biomass in wet season than dry season however, seed production showed vice versa trend and hence relatively profitable to produce seeds in dry season. It is therefore recommended that the use of irrigation and proper fertilizer rates for grass pasture seed production can be a potential option for improved quality and quantity of grass seed production to meet demands of livestock producers. en_US
dc.description.sponsorship Agricultural Sector Development Programme (ASDP) en_US
dc.language.iso en en_US
dc.publisher Sokoine University of Agriculture en_US
dc.subject Seed yield en_US
dc.subject Cenchrus ciliaris cv. Biloela en_US
dc.subject Agronomic practices en_US
dc.subject Sub-humid en_US
dc.subject Eastern zone en_US
dc.subject Tanzania en_US
dc.title Seed yield and quality of Cenchrus ciliaris cv. Biloela under various agronomic practices in sub-humid eastern zone of Tanzania en_US
dc.type Thesis en_US

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