Crop Science and Production Collection

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    Heritability, stability parameters and paths of influence on yield components of sesame (sesantutn indicum L.) breeding lines
    (Sokoine Univesirty of Agriculture, 2014) Daudi, Happy M.
    Field trials were conducted during the rainy season of 2012 to study the heritability, stability and contributions of some yield attributes to the seed yield of 9 sesame genotypes grown in two spacings at Naliendele, Nachingwea and Tunduru. The experiments were arranged in a split-split plot design in three replications at three sites. Observations were recorded on days to 50% flowering, total plant height, height to first branch, height to first capsule, number of primary branches, capsule on the main stem, number of capsules per plant, leaf spot score, date of harvesting, seed yield and 1000 seed weight. The genotypes varied considerably in the two spacings and GEI was highly significant. The traits, number of first branch, number of capsules per plant and seed yield showed high PCV and GCV estimates. There is scope for selection based on these characters, and the diverse genotypes can provide materials for a sound breeding programme. Most of the characters had low heritability along with low genetic advance; such situation may arise due to non-additive gene action indicating greater influence of environment in the expression of these characters. Seed yield per plant showed positive correlation with days to 50% flowering, total plant height, height to first branch, height to first capsules and capsule per plant. 1000 seed weight showed negative association with seed yield per plant. Genotype Nal. 06. Sc 31 was high yielding and found to suit in more favourable environmental conditions while Mtwara 09 showed to have good adaptability under more unfavourable conditions. According to this experiment, it was concluded that specific genotypes for specific environments are needed in order to maximize grain yield in sesame.
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    Genetic diversity study of vanillaplanifolia g. jackson, syn. v. fragrans crop grown in Tanzania using molecular technique
    (Sokoine Univesirty of Agriculture, 2010) Busungu, Constantine
    Vanilla (Vanillaplanifolia G. Jackson, syn. V. fragrans) is native to the tropic-forest of Mexico. In Tanzania it vanilla has been cultivated in small quantities since in the 1940s in Kagera Region but a decline in coffee prices world-wide in the 1990s resulted into its increased cultivation as an alternate crop in Kagera and Kilimanjaro Regions. Vanilla which has a remarkable high price compared to coffee has consequently spread to Kilimanjaro and Morogoro Regions, and Zanzibar Island. This study was undertaken to examine the extent of genetic diversity of Vanilla planifolia cultivars grown in Tanzania using molecular technique. A total of 126 samples were randomly collected from Bulinda, Bakabuye and Kibona villages (Kagera Region), Mudio and Kidia villages (Kilimanjaro Region), Mkunazini and Donge villages (Zanzibar Island). Dellaporta protocol method was used in deoxyribonucleic acid (DNA) extraction. DNA quantification was done by comparing band intensity of standard genomic DNA using agarose gel electrophoresis. For the optimization of Polymerase Chain Reaction (PCR), three different components; dNTPs, Taq polymerase and MgCh were tested in different combinations.Ten primers were selected for the Random Amplified Polymorphic DNA (RAPD) reactions. These results revealed genetic distances of 0.667, 0.705 and 0.805 for Kagera, Kilimanjaro and Zanzibar, respectively for intra-population diversity and 1.28 for inter-population diversity indicating a narrow genetic diversity. Similarly, the samples used in this study generated 53 bands of which only 27 indicated a low level polymorphism. Vanilla cultivars from Kilimanjaro and Kagera did not markedly diverge genetically from those from Zanzibar Island suggesting a narrow genetic diversity among populations. These results further signify that cultivars used may have been derived from common parent sources of over several decades. Exchange of cultivars as planting materials may have played a role in this in phenomenon.
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    Effects of striga asiatica (L.) Kuntzc and Rhaniphicarpa fistulosa (Hochst) Benth. seed densities on physiology and yielding ability of rice (Oryza sativa L.)
    (Sokoine University of Agriculture, 2014) Constantine, John
    Striga asiatica and Rhamphicarpa fistulosa greatly affects rice productivity in infested fields. To address this problem, two screen house experiments were conducted at Sokoine University of Agriculture during September, 2012 to February, 2013 to study the effects of parasitic weed seed densities of S. asiatica and R. fistulosa on physiology and yielding aptitude of rice. In one of the experiments eight S. asiatica densities were planted with single host rice (variety IAC 165) while in the second experiment, seven R. fistulosa densities were planted with single host rice (variety IR64). Both experiments were laid out in a Completely Randomized Block Design (CRBD) with five replicataions. In addition, a supplementary experiment was conducted to study the intra specific competition between R.jistulosa plants under monoculture where six R.fistulosa seed densities (31, 62, 125, 250, 500 and 1000 seeds/pot) were sown without host. In the S. asiatica density experiment, the highest value on stomatal conductance was recorded in the parasite free pots (205.8 mmol/ni2 s) while the lowest was recorded in the plants with the highest S. asiatica infestation densities (21 mmol/(m2s). At 60 DAS there was a significant difference (P<0.05) between the treatment means chlorophyll content from 20.8 in highest S. asiatica density (47 840 seeds/pot) to 34.1 in S. asiatica free pots. The highest average total rice biomass was recorded in non-infested pots (2.5 g/pot) while the lowest was recorded in the highest S. asiatica infestation density (0.5 g/pot). In R. fistulosa density experiment there was significant difference in stomatal conductance (P<0.05) at 60 DAS i.e. (202.8 mmol/(m2,s) from R. fistulosa free plants and (143.6 mniol/(m2 s) from lowest R. fistulosa infestation density. At 60 DAS, the highest average value of chlorophyll fluorescence (0.66) was recorded in R. fistulosa free plants while the lowest (0.413) was recorded from plants in the highest R. fistulosa infestation density (1000 R. fistulosa seeds/pot). The highest rice biomass was obtained from R. fistulosa free plants (5.42 g/pot) while the lowest was recorded in the highest R. fistulosa infection levels (0.68 g/pot). On the basis of these results, it was concluded that S. asiatica and R. fistulosa affect rice physiology and yielding ability.
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    Population structure of xanthonionas oryzae pv. oryzae and rice cultivar resistance in three regions in Tanzania
    (Sokoine University of Agriculture, 2014) Mwenda, Meshack M.
    This study determined the pathogen population structure and the reaction of rice cultivars against Xanthonwnas oryzae pv. oryzae. Field trapping nurseries were established at Dakawa, Bunda and Kyela and inoculations for pot experiment were conducted at Agricultural Research Institute-Uyole from December, 2012 - July, 2013. Twenty two rice cultivars obtained from Agricultural Research Institute-Uyole and twenty one near isogenic lines from AfricaRice Program, Dar-es-Salaam, Tanzania were arranged in a completely randomized design and randomized complete block design in screenhouse and field experiments, respectively. Nineteen isolates of the pathogen were obtained from the study areas and used for physiological and biochemical tests. Data on incidence and severity were subjected to analysis of variance (ANOVA). Duncan's Multiple Range Test was used to separate means. Six pathotypes namely; TK3CD, TK4E, TM2C, TM2B, TB2F and TB5A were identified frorfi the presumed nineteen isolates of the pathogen. Results showed that IR-BB4 and IR-BB52 were resistant to Xanthomonas oryzae pv. oryzae with significantly (P = 0.05) low disease incidence (8.18 % and 6.72 %) and severity (0.5 cm and 0.65 cm), respectively. IR-BB 14 was highly susceptible with 61.55 % disease incidence and 6.12 cm disease severity. The cultivars Domo la Fisi, Rangi Mbili, Tule na Bvvana, Jicho la Samola, Rufiji, SARO 5, Mtalima Wangu, Zambia and Supa showed intermediate resistance compared to the IR24 (control). The IR-BB4 and LR-BB52 are therefore, possible promising rice lines that can be incorporated into rice breeding programs in Tanzania.
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    Potential of sesbania rostrata green manure in rice production
    (Sokoine University of Agriculture, 1993) Lwekoramu, Prudence Edward
    The potential of S. rostrate as a green manure for rice production was evaluated in two pot, glasshouse experimentsat Morogoro using a sandy clay (Vertic ustifInvent) soil.split plot biomass experiment was and production conducted to study the A plant f ixation/accumulation. Nitrogen Plants were raised both under flooded/waterlogged paddy and drained conditions for 60 days with Rhizobium either the seeds, alone were studied.The effects of inoculating seeds + steins, or steins The plant1s manurial effect in terms of nitrogen release under flooded and drained soil conditions were studied in a factorial experiment. A 45-day old S.rostrata green manure (3.26% N) was incubated in soil at Q,10,20 and 30 ton/ha and the nitrogen release patterns studied for a period of 28 days.S. rostrata, generally, grew well in both soil moisture regimes. Biomass and nitrogen accumulation were in favour of drained soils up to 45 days, and, thereafterz flooded soils due to infestation by nematodes in drained soils.Inoculation increased root and/or stem nodulation,plant biomassz plants and N2 fixation compared to non-inoculated No significant differences were observed between inoculation techniques.The equivalent of up to 20 and 34 ton/ha green biomass and 97 and 200 kg N/ha were recorded in 45 and 60 days, respectively. On decompositionf no differences were observed between flooded and drained soils in terms of soil total N. Available N released was substantial but significantly more in flooded soils where NH4-N dominated than in drained soils dominated by NO3-N.Higher levels of green manure released higher amounts of N. The larger amounts of N accumulated by the plantsr and the substantial amounts of mineralized N during the green manure decomposition in the soils, qualify S. roctrata as a potential biofertilizer in rice production.
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    Identification and correction of some micronutrient constraints in a volcanic soil from Mpangala village, Makete district for optimization of maize yields.
    (Sokoine University of Agriculture, 2003) Lisuma, Jacob Bulenga
    A study was conducted in field and glasshouse conditions to identify and correct some micronutrient constraints in Mpangala volcanic soil for optimization of maize yields. The study involved routine soil analysis, pot experiments and a field experiment. Soil analysis revealed the level of Cu to be 0.14 mg kg*1, which was ranked as deficient; Zn was 0.86 mg kg' (marginal) and boron was 0.52 mg kg"1 (medium). In the first pot experiment, P and N were applied at constant rates of 160 mg kg'1 and 240 mg kg'1, respectively. However in one treatment a higher rate of 320 mg P kg-1 was applied in order to test whether a higher rate of P was still required in Mpangala soil. Boron was applied at rates of 0 and 2 mg-kg'1, Cu at rates of 0 and 5 mg kg'1 and Zn at rates of 0 and 10 mg kg-1. The results indicated that a combination of Cu, N and P increased yields dramatically. Moreover the treatment that received the high P rate of 320 mg kg'1 together with N, B, Cu and Zn fertilizers had significantly (p = 0.05) higher DM yield than the Cu treatment. Analyses of plant leaves showed very low concentrations of Cu followed by Zn. However, Zn did not increase DM yield significantly. It was concluded that Zn may be the next limiting nutrient after Cu. A second pot experiment was conducted to estimate the optimum rate of Cu. Nitrogen and P were applied at constant rates of 240 and 320 mg kg", respectively, and Cu at rates of 0, 5, 7.5, 10, 15 or 20 mg Cu kg'1. The experiment indicated the rate of 20 mg Cu kg'1 to be optimum in Mpangala soil. In the field experiment, significantly (p = 0.05) higher grain yield of 5.84 ton ha'1 was obtained when 2.5 kg Cu ha-1 was applied. The results in this study revealed that Cu was the most limiting micronutrient in Mpangala soil, followed by Zn. Zinc may need to be added in addition to Cu, after one harvesting cycle, in order to provide proper nutrition to the maize crop in the long run. Higher rates of N and P may still be beneficial, especially if Cu and Zn are optimized.
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    Response of rice yield to rat damage in irrigated rice (oryza sativum l.) in Mvomero district, Morogoro, Tanzania.
    (Sokoine University of Agriculture, 2016) Lagwen, Philorentin Philp
    Rodents often damage crops throughout the growing season, from germination to harvest, thus making it difficult to understand its cumulative effects for crops such as rice that arc able to partially compensate. This study examines response of rice yield to rat damage in farmer's fields and simulated rat damage in irrigated and rain-fed rice (Oiyza sativum L) in Morogoro, one of Tanzania's granary areas. The study was conducted at Hembeti village in Mvomero district from September, 2012 to July, 2013 where variety TXD 306 was used. Two field experiments; viz: farmers^ managed rice field and rodent simulation damage were conducted. The experimental design for farmer's field study was split plot laid in Completely Randomized Design (CRD) and a split-split plot layout in a Randomized Complete Block Design (RCBD) with three replications for simulation rat damage experiment. Five damage levels (i.e. cuts at 0%, 10%, 20%, 25% and 50%) at different rice growth stages (i.e. transplanting, vegetative and maturity) and seasons (i.e. dry and wet) were carried out for later experiment. Results show that there were no significant differences in rodent abundance between seasons and crop growth stage in farmer's managed rice fields. Mastomys naialensis was the most abundant rodent pest species while Grammomys doUchurus was found in small proportions. Higher yield was recorded during the wet season compared with the dry season. Yield loss was observed during all cropping stages fbr all levels of simulated rat damage for wet and dry season crops, with significant compensation noted at the transplanting stage. Damage above 10% stem cut and at vegetative and maturity stage resulted in significant reductions in rice yield. Grain yield was highly and positive correlated with number of panicles per plant and panicles m'2, filled grains per panicle, percentage grain fill and 1000 grain weight.
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    Evaluation of rice (oryza sativa £.) genotypes for adaptability to heat stress under controlled conditions in Morogoro
    (Sokoine University of Agriculture, 2014) Vitta, Masanche Rajab
    A study was conducted in the 2012/13 growing season, at Horticulture unit screen house and heat chamber at African Seed Health Centre in the Department of Crop Science and Production at Sokoine University of Agriculture. Morogoro. The aim of this study was to evaluate rice genotypes for adaptability to heat stress under controlled conditions in Morogoro, whereas, mutant rice genotypes originating from Kihogo red (Local variety), CG 14 (O.glaberrima), WAB 56-50 and WAB 56-104 {O. saliva) were evaluated. The results from screening of rice mutant lines which were subjected to heat stress at 45°C for different days of exposure showed variation in survival among genotypes tested. The survived rice seedlings were laid out as pot experiments in a completely randomized Design with three replications in the screen house. Data collected included plant survived from heat chamber, Days to 50% flowering, Tiller number per plant, panicle number per plant, plant height, panicle length, number of spikelets per plant, percentage sterility, 1000 grain weight, and grain yield per plant. Data were subjected to the analysis of variance (ANOVA). The results revealed that there were significant differences among the genotypes for all traits studied. In this study the effects of temperature were observed in plant height, Days to 50% flowering, panicle length, number of sp汰elets per panicle, 1000 grain weight, in almost all mutants whereas, grain yield of WAB 45-104 and 56-50 mutants were affected significantly. Also the following traits were favored by high temperature; Percent sterility, number of panicles per plant, number of tillers per plant and grain yield per plant for Kihogo red and CG 14. The phenotypic screen revealed the following mutants lines to be heat tolerant; KR 37, CG-14-7, CG 14-13,CG 14-16, WAB 56-104-36, WAB 56-104-43, WAB 56-104-82, WAB 56-104-40, WAB 56-104-12, WAB 56-104-123, WAB 56-104-181, WAB 56-50-82 and WAB 56-50-132. Therefore these lines could be grown in the area where temperature exceeded the normal range for rice cultivation.
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    Towards domestication of Kihansi wild coffee (coffea Kihansiensisy): population dynamics, propagation and diversity
    (Sokoine University of Agriculture, 2018) Makwinja, Faraja
    Potential of this wild co flee can be utilized as gcneiic resource for coffee breeding program and/or domeslicalion but iintbriunalcly ihe population struciurc. propagation poienlial and genetic variability of the discovered Kihansi wild co flee is poorly known. 1'herefbre. characlerizalion and population study is highly needed hence, this study aims to (i) Assessing the population chnamics of Coflea kihunsiensis (ii) Optimizing vegetative propagation of Coffeu kihansiensis (iii) Characterizing morphological traits of Kihansi wild coffee kiluuisiensis) and (iv) Assessing lhe gcneiic diversity of Kihansi wild co Hee. Populaiion dynamics assessment using quadrat method was done. Variability of population density, lowest in lower upper and upper block while highest population density was observed in lower spray. High proponional of matured plant were observed in both two seasons wiih lowest number of dead plants. In optimizing vegetative propagation, sand as propagation media provided promising results with good rooting ability, high survival rate and highest root number compared to decomposed rice husks (DRH) and un-dccomposcd rice husks (UDRH). About 62.52 % and 72.42 % population variation detected based on vegetative and icpioduciive traits respectively. Plant habit. branching habit, angle of* primary branches, berr、and cherry length, width and diameter are lhe most signiilcant traits expressed the morphological variations. These variations were confirmed in genetic diversity study using SSK markers. About 97 % of the total variation was detected within populations. Four clusters varied at 60 % were obtained. These findings are useful in planning conservation and management strategies while providing insight on utilization of this coffee as genetic resource for coffee improvement. Key words: Coffeu kihansiensis. genetic variability, population density and improvement.
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    A genetical analysis of yield and yield components in an s-parent diallel cross of spring barley
    (Sokoine University of Agriculture, 1979) Mrimi,Geremiah A.
    An 8 x 8 dlallel experiment involving parental and F2 progenies was conducted in the field at the Uyole Agricultural Centre, Mbeya, Tanzania In the 1977-78 growing season.The aim vias to obtain information on the magnitude and type of genetic variability for yield and its components, to estimate the magnitude of the various genetic components and to investigate the nature and magnitude of the correlations between yield and its components.Results indicate that additive and non«^dditive variation xvas present for all characters measured.The non-additive portion was greater than the additive portion for all characters except number of ears per plant. Dominance was found for all characters and it was the main source of non-additive variation. Average degree of dominance for the characters measured varied from partial dominance to overdominance•Epistasis was found to be small, and it was detected in the characters plant height, number of grain per ear, grain yield per plant and 1000 grain weight. Overall heterosis was found in the characters number of days to heading, plant height, ear length, grain yield per plant and 1000 grain weight. However,its magnitude and direction was4 specific to the cross.Heterosis for yield was generally associated with heterosis for the yield components, paarticularly number of ears per plantv number of grains per ear, earliness and plant height.Maternal effects were found for grain yield per plant and 1000 grain weight. Estimates of narrow sense heritability showed that aJ.l characters, except plstnt height, had values greater than 40?.'.Number of ears per plant showed the highest value (93»0fJ) while plant height had the lowest (24.3Q.High yield per plant and high 1000 grain weight were associated with dominance, while lateness and high number of grains per ear were associated with recessiveness.Correlation studies showed that the characters number of ears per plant, plant height, ear length, grain yield per plant and 1000 grain vzeight were positively intercorrelated• Number of grains per ear was negatively correlated with number of ears per plant and 1000 grain weight. Number of days to heading showed significant negative correlation with all characters except ear length and number of grains per ear.The implications of the results to barley improvement are discussed.
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    Genetic diversity of Tanzanian and Kenyan adapted landraces of cowpea, sorghum and pigeonpea
    (Sokoine University of Agriculture, 2016) Msengi, Zabron Mkumbo
    Improvement of cowpea, pigeonpea and sorghum can be enhanced by knowledge of genetic diversity available between and within accessions. This variability is the foundation of all three crop improvement programs. A total of 85 accessions as 22 cowpea, 32 pigeonpea and 31 sorghum from Tanzania and Kenya gene banks were used for this study. Quantitative and qualitative traits such as, grain color, grain coverage, seed shape, days to 50% flowering, plant height, days to 50% maturity and grain yield were among the few traits used to assess the collected accessions. The main objective of the study was to determine existing diversity of three food security crop accessions in Tanzania. Different agro- morphological traits collected were analyzed using GENSTAT 15 and XLSTAT 2014 statistical packages to determine Phylogenetic relationship of the three selected crops based on agro-morphological traits. Accessions were classified based on their agro-morphological relationships using principal component analysis and un­ weighted pair-group average cluster analysis. Results showed a relatively high level of genetic diversity between and within both accessions; levels of similarity differed for qualitative and quantitative data for all three crops. Some quantitative agro-morphological traits such as days to 50% flowering, days to maturity, seed width, pods per plant in cowpea, grain weight per panicle, grain number per panicle, grain yield, number of nodal tillers per plot in sorghum; days to maturity, plant height and raceme number per plant in pigeonpea. For qualitative traits, raceme position for cowpea; grain color and bird attack for sorghum; seed color pattern for pigeonpea were distinguished more efficiently between and within the accessions to get superior materials for future use in breeding programs. A few of the best materials selected were GBK 013187 (cowpea), TZA 2496 (pigeonpea) and TZA 3991 (sorghum). In a number of groups the accessions were different from other accessions in some important traits. Implications of the variability in pigeonpea, cowpea and sorghum improvement are discussed.
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    Effects of nitrogen fertilizer, sugarcane trash mulch, cowpea intercrop and herbicides on itchgrass control, yield and quality of sugarcane
    (Sokoine University of Agriculture, 1994) Njalayao, Anthony Herman
    A field experiment was conducted (under rainfed conditions with supplimentary irrigation) to evaluate the effects of nitrogen fertilizer, post emergence herbicides and other weed control treatments on itchgrass ( Rottboellia cochinchinensis (Lour) Clayton) control, yield and quality of sugarcane ( Saccharum officinarum L.). The experiment was laid out as split-plot randomized complete block design replicated in a four times. Nitrogen fertilizer rates (0, 50 and 100 kg N/ha) were main plots while herbicides and other weed control treatments were subplots. The herbicides included gramuron (3.2 kg a.i/ha), basta (2.0 kg a.i/ha) and asulam (3.7 kg a.i/ha). Other weed control treatments were cane trash mulch, cane trash mulch plus hand weeding, intercrop plus hand weeding, cowpea intercrop, gesapax combi cowpea (4 kg a.i/ha) plus two hand weedings plus mechanical cultivation, weed free and unweeded checks. Nitrogen fertilization was ineffective in controlling itchgrss. Mulching or intercropping supplemented with hand weeding as well as gesapax combi (4 kg a.i/ha) plus two hand weedings plus mechanical cultivation completely eliminated itchgrass. Asulam (3.7 kg a.i/ha) controlled the weed by an average of 88%. Gramuron (3.2 kg a.i/ha) basta(2.0 kg a.i/ha) and mulching had between 70 and 75% control of the weed. Intercropping was ineffective in itchgrass control. Increasing the rate of nitrogen from 0 to 100 kg N/ha significantly (P<0.05) increased cane yield by 14%. Plots which were mulched and then weeded, hand treated with asulam (3.7 kg a.i/ha) or gesapax combi (4 kg a.i/ha) plus two hand weedings better control plus of mechanical itchgrass cultivation provided higher and cane yields averaging between 85 and 88 tons/ha. Sugarcane yields positively correlated with number of sugarcane tillers (r=0.766), stalk population (r=0.734) and stalk length (r=0.433). Among sugarcane growth parameters, tiller length counts, of number negatively harvestable correlated stalks (r=0.749, and 0.850, stalk 0.886 respectively) with itchgrass count. Analysis of coefficient 9 of determination (r ) influenced (r^=0.60) indicated that cane yield was more by tiller counts than by the other parameters. Application of 100 kg N/ha reduced sucrose content which is significantly (P<0.05) the main parameter sugarcane quality compared to unfertilized cane. ofiv Economic analysis showed that mulching plus hand weeding applied with 100 kg N/ha had the highest marginal rate of return of 192%.
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    Evaluation of rice (oryza sativa £.) genotypes for adaptability to heat stress under controlled conditions in Morogoro
    (Sokoine University of Agriculture, 2014) Vitta, Masanche Rajab
    A study was conducted in the 2012/13 growing season, at Horticulture unit screen house and heat chamber at African Seed Health Centre in the Department of Crop Science and Production at Sokoine University of Agriculture. Morogoro. The aim of this study was to evaluate rice genotypes for adaptability to heat stress under controlled conditions in Morogoro, whereas, mutant rice genotypes originating from Kihogo red (Local variety), CG 14 (O.glaberrima), WAB 56-50 and WAB 56-104 {O. saliva) were evaluated. The results from screening of rice mutant lines which were subjected to heat stress at 45°C for different days of exposure showed variation in survival among genotypes tested. The survived rice seedlings were laid out as pot experiments in a completely randomized Design with three replications in the screen house. Data collected included plant survived from heat chamber, Days to 50% flowering, Tiller number per plant, panicle number per plant, plant height, panicle length, number of spikelets per plant, percentage sterility, 1000 grain weight, and grain yield per plant. Data were subjected to the analysis of variance (ANOVA). The results revealed that there were significant differences among the genotypes for all traits studied. In this study the effects of temperature were observed in plant height, Days to 50% flowering, panicle length, number of sp汰elets per panicle, 1000 grain weight, in almost all mutants whereas, grain yield of WAB 45-104 and 56-50 mutants were affected significantly. Also the following traits were favored by high temperature; Percent sterility, number of panicles per plant, number of tillers per plant and grain yield per plant for Kihogo red and CG 14. The phenotypic screen revealed the following mutants lines to be heat tolerant; KR 37, CG-14-7, CG 14-13,CG 14-16, WAB 56-104-36, WAB 56-104-43, WAB 56-104-82, WAB 56-104-40, WAB 56-104-12, WAB 56-104-123, WAB 56-104-181, WAB 56-50-82 and WAB 56-50-132. Therefore these lines could be grown in the area where temperature exceeded the normal range for rice cultivation.
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    Effect of variety mixtures on cowpea vegetable leaf and seed yields in a traditional cowpea/maize intercropping system in the semi-arid tropics of Uganda
    (Sokoine University of Agriculture, 2009) Okonya, Joshua S.
    Cowpea is considered to be one of the top four leafy vegetables in Uganda grown for both its seed and leaves. Vegetable leaves are more popular than seed in the Eastern and Northern parts of the country and are a source of protein and micronutrients for the resource-poor subsistence farmers. Cowpea is usually grown in intercrop with maize, sorghum, cassava or mung bean but sole cropping is also practiced by several farmers. Most farmers in Soroti and Kumi districts continue to grow landraces (‘Ecirikukwai’ and ‘Ebelat’) because no improved varieties have been successfully bred/promoted. Erratic rainfall, low soil fertility and insect pests are among the most important constraints to cowpea production in Uganda leading to low seed yields (200-400 kg/ha) while leaf yield levels had never been assessed. Agronomic strategies to optimise both leaf and seed yields like through the use of variety mixtures are long overdue. Variety mixtures containing up to four cowpea varieties were grown in intercrop with maize during the first cropping season of 2008 at NaSARRI, Serere, Kikota village and Kogili village in Eastern Uganda. The results of these three experiments indicated that: accumulated dry matter leaf yield from 3-4 harvests and seed yield ranged from 34.7 to 70.9 kg/ha and 33.4 to 551.2 kg/ha, respectively. There was no significant difference between accumulated leaf yield of mixtures and the means of their respective component varieties. Though not significant, mixtures had both positive (4.3 to 111.4%) and negative (3 to 72.5%) effects on seed yield. Seed and leaf yield did not always increase with increasing number of component varieties in a mixture. The leaf-harvesting strategy employed by farmers enhanced seed yield in some but not all the treatments. Seed yield components like pod number, seeds/pod and 100- seed weight were not significantly affected by leaf-harvesting. On average, leaf yield was more stable in plots with mixtures than those with single cowpea varieties. Levels of leaf protein and iron ranged from 27.9 to 34.8% and 164.1 to 796.3 pg/g, respectively. Cowpea leaves were ranked first by farmers from the region among the top four leafy vegetables of spider-flower, amaranth and white cabbage.
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    Comparative effectiveness of animal manures on soil chemical properties, yield and root growth of amaranthus (antaranthus cruentus l.)
    (Sokoine University of Agriculture, 1999) Nonga, Dotto Leonard Mhoja
    Pot and field experiments were conducted at Sokoine University of Agriculture (SUA), Morogoro, Tanzania during the 1997/98 cropping season. The study was carried out to comparatively evaluate the effectiveness of dairy cow, goat and poultry manures on soil available levels of N and P, amaranthus (Amaranthus cruentus L.) yield and root growth. In both experiments, the three amendments were applied at 100, 150 and 170 kg N/ha. The experiments were laid out in a split plot design, replicated three times with rates of application as mainplots and animal manure types as subplots. Pot experiment was conducted for a period of about one-month whereas field experiment was carried out over three crop cycles each lasting for about one month. The soil used in this study was classified as an Oxisol (Tropeptic Entrustax). Results of the glasshouse experiment indicated that applications of the three animal manures significantly (P < 0.01) increased soil available levels of N and P, amaranthus shoot dry matter yield, tap root length, root weight and tissue concentrations of N and P. These responses increased with increasing rate of application with the highest rate of application (170 kg N/ha) resulting in highest responses. Comparison of the responses from the three manures revealed that for all the parameters evaluated the trend was; poultry manure > goat manure > dairy cow manure. This trend was mainly due to differences in total N, total P, C/N and CZP ratios of the three manures. Poultry manure had highest levels of total N and total P and narrowest C/N and C/P ratios concurring with the superior mineralization of N and P observed and consequently, the highest responses in amaranthus yield and root growth compared to the other two manures. Results of the field experiment were essentially similar (except for the root growth which was not evaluated in this experiment) to those of the pot experiment. Soil available levels of N and P evaluated after first and third crop harvests were highest for poultiy manure followed by goat and dairy cow manures and the responses were highest after the third crop harvest suggesting that mineralization of organic forms of N and P increased with time. The above responses were significantly (P < 0.01) and positively correlated to amaranthus yield and tissue concentrations of N and P indicating that the observed response in amaranthus yield was largely due to soil availability and uptake of N and P. Based on the fertilizer recommendation of N and P for Southern Highlands of Tanzania (N= 40 kg N/ha and 20 kg P/ha) and the application rate of 170 kg N/ha used in this study, applications of 5.8 tons/ha of poultry manure, 9.8 tons/ha of goat manure and 13.4 tons/ha of dairy cow manure will meet the recommendation of 40 kg N/ha. The above application rates will also provide 30.5kg P/ha, 31.6 kg P/ha and 26.8 kg P/ha for the respective manures, which will suffice the P recommendation. Results of this experiment therefore, suggest that the three types of animal manures evaluated could substantially sustain crop growth in this soil and others with similar properties. The results should however, be confirmed under different field conditions and for much longer experimental duration.
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    Comparative effectiveness of animal manures on soil chemical properties, yield and root growth of amaranthus (antaranthus cruentus l.)
    (Sokoine University of Agriculture, 1999) Nonga, Dotto Leonard Mhoja
    Pot and field experiments were conducted at Sokoine University of Agriculture (SUA), Morogoro, Tanzania during the 1997/98 cropping season. The study was carried out to comparatively evaluate the effectiveness of dairy cow, goat and poultry manures on soil available levels of N and P, amaranthus (Amaranthus cruentus L.) yield and root growth. In both experiments, the three amendments were applied at 100, 150 and 170 kg N/ha. The experiments were laid out in a split plot design, replicated three times with rates of application as mainplots and animal manure types as subplots. Pot experiment was conducted for a period of about one-month whereas field experiment was carried out over three crop cycles each lasting for about one month. The soil used in this study was classified as an Oxisol (Tropeptic Entrustax). Results of the glasshouse experiment indicated that applications of the three animal manures significantly (P < 0.01) increased soil available levels of N and P, amaranthus shoot dry matter yield, tap root length, root weight and tissue concentrations of N and P. These responses increased with increasing rate of application with the highest rate of application (170 kg N/ha) resulting in highest responses. Comparison of the responses from the three manures revealed that for all the parameters evaluated the trend was; poultry manure > goat manure > dairy cow manure. This trend was mainly due to differences in total N, total P, C/N and CZP ratios of the three manures. Poultry manure had highest levels of total N and total P and narrowest C/N and C/P ratios concurring with the superior mineralization of N and P observed and consequently, the highest responses in amaranthus yield and root growth compared to the other two manures. Results of the field experiment were essentially similar (except for the root growth which was not evaluated in this experiment) to those of the pot experiment. Soil available levels of N and P evaluated after first and third crop harvests were highest for poultiy manure followed by goat and dairy cow manures and the responses were highest after the third crop harvest suggesting that mineralization of organic forms of N and P increased with time. The above responses were significantly (P < 0.01) and positively correlated to amaranthus yield and tissue concentrations of N and P indicating that the observed response in amaranthus yield was largely due to soil availability and uptake of N and P. Based on the fertilizer recommendation of N and P for Southern Highlands of Tanzania (N= 40 kg N/ha and 20 kg P/ha) and the application rate of 170 kg N/ha used in this study, applications of 5.8 tons/ha of poultry manure, 9.8 tons/ha of goat manure and 13.4 tons/ha of dairy cow manure will meet the recommendation of 40 kg N/ha. The above application rates will also provide 30.5kg P/ha, 31.6 kg P/ha and 26.8 kg P/ha for the respective manures, which will suffice the P recommendation. Results of this experiment therefore, suggest that the three types of animal manures evaluated could substantially sustain crop growth in this soil and others with similar properties. The results should however, be confirmed under different field conditions and for much longer experimental duration.
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    Evaluation of rice (oryza sativa £.) genotypes for adaptability to heat stress under controlled conditions in Morogoro
    (Sokoine University of Agriculture, 2014) Vitta,Masanche Rajab
    A study was conducted in the 2012/13 growing season, at Horticulture unit screen house and heat chamber at African Seed Health Centre in the Department of Crop Science and Production at Sokoine University of Agriculture. Morogoro. The aim of this study was to evaluate rice genotypes for adaptability to heat stress under controlled conditions in Morogoro, whereas, mutant rice genotypes originating from Kihogo red (Local variety), CG 14 (O.glaberrima), WAB 56-50 and WAB 56-104 {O. saliva) were evaluated. The results from screening of rice mutant lines which were subjected to heat stress at 45°C for different days of exposure showed variation in survival among genotypes tested. The survived rice seedlings were laid out as pot experiments in a completely randomized Design with three replications in the screen house. Data collected included plant survived from heat chamber, Days to 50% flowering, Tiller number per plant, panicle number per plant, plant height, panicle length, number of spikelets per plant, percentage sterility, 1000 grain weight, and grain yield per plant. Data were subjected to the analysis of variance (ANOVA). The results revealed that there were significant differences among the genotypes for all traits studied. In this study the effects of temperature were observed in plant height, Days to 50% flowering, panicle length, number of sp汰elets per panicle, 1000 grain weight, in almost all mutants whereas, grain yield of WAB 45-104 and 56-50 mutants were affected significantly. Also the following traits were favored by high temperature; Percent sterility, number of panicles per plant, number of tillers per plant and grain yield per plant for Kihogo red and CG 14. The phenotypic screen revealed the following mutants lines to be heat tolerant; KR 37, CG-14-7, CG 14-13,CG 14-16, WAB 56-104-36, WAB 56-104-43, WAB 56-104-82, WAB 56-104-40, WAB 56-104-12, WAB 56-104-123, WAB 56-104-181, WAB 56-50-82 and WAB 56-50-132. Therefore these lines could be grown in the area where temperature exceeded the normal range for rice cultivation.
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    Control of cashew sucking bugs helopeltis anacard11 and pseudotheraptus wayi by manipulating the african weaver ants (oecophylla long1noda) populations in cashew nut trees
    (Sokoine University of Agriculture, 2002) Mwinyi, Waziri Ali
    Five field experiments were conducted during the 2000/2001 season at ARI-Naliendele. Mtwara region in southern Tanzania. The general objective of the study was to establish optimum population levels of weaver ants that will give effective control of Helopeltis anacardii and Pseudotheraptus wayi in cashew nut trees. The experiments were also conducted to establish the bionomics ofthe population of the cashew pests H. anacardii and P. wayi, and the predator. Oecophylla longinoda in relation to the antagonistic ant. Pheidole megacephala. Assessment of shoot and nut damage, and associated yield were carried out to establish the effectiveness of the predator against the two pests. The study has shown that high levels of O. longinoda had significant effects in protecting cashew trees from attack by H. anacardii and P. wayi Manipulation of number of nests of O. longinoda confirmed that 30 and 40 nests can provide maximum protection of cashew trees. The protective effect of the biological agent led to reduction of damage levels in shoots and nuts due to reduced number of pests and increased nut yield/tree. When the performance of the biological agent at different nest levels was compared to chemical control using lamda cyhalothrin (5 %). the chemical was found to be less effective as compared to cashew trees subjected to 30 or more O. longinoda nests. The antagonistic ant. P. megacephala. to the biological agent O. longinoda was successfully suppressed by Amdro bait. Reduction in population of the competitor ant resulted to increased numbers of (). longinoda in the field, and increased predation activity against the pests. Significant variations (P 0.05) of damage levels between trees subjected to weaver ants alone and those subjected to weaver ants in combination with Amdro bait were evident. Lowest damage levels were recorded in trees treated with Amdro bait in combination with weaver ants. It is concluded that weaver ants have a great potential for suppressing H anacardii and P. wayi to low uneconomic levels. However, for a successful establishment of weaver ants in the field, controlling of the antagonistic ants P. megacephala is essential.
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    Effect of urea and cowpea residues on growth and yield of rice variety makassane in Zambezia, Mozambique
    (Sokoine University of Agriculture, 2012) Dinheiro, Virgilio Agostinho Gabriel
    A field experiment was conducted to assess the effectiveness of cowpea residues (CR), and combination of urea as source of nitrogen on growth and yield of rice variety Makassane. A randomized complete block design (RCBD) was used with six treatments and three replications. The six treatments were control plot, 0% urea + 100% CR, 25% urea + 75% CR, 50% urea + 50% CR, 75% urea + 25% CR and 100% urea + 0 % CR. Soil and organic material analysis revealed that the soil was deficient in N. Data recorded were number of tillers, plant height, leaf area, days to 50% flowering, 1000 grain weight, days to physiological maturity, total dry matter, panicles per plant, spikelets per panicle and grain yield. The recorded data were analyzed by the analysis of variance and stepwise multi-regression techniques. The result showed that sole cowpea residues, urea and different combinations of organic and inorganic fertilizers significantly produced comparable higher rice grain yields over the control plot. Overall, the study results indicated that combination of organic and inorganic source of nitrogen at the rate of 50% urea + 50% CR could be the best combination strategy in improving rice grain yield. Furthermore, it is concluded that cowpea residues instead of urea could be used as a source of nitrogen for improving rice production.
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    Evaluation of quality protein maize synthetic germplasm for drought tolerance
    (Sokoine University of Agriculture, 2008) Bilaro, Atugonza Luta
    Twenty one Open Pollinated Quality Protein Maize genotypes were evaluated fbr drought tolerance under three conditions of moisture regimes i.e. pre flowering stress, flowering moisture stress and optimal moisture to identify genotypes that maintained high yield under drought and well watered conditions. The experiment was conducted at Ilonga research station during rain free period of August to November, 2006, and Selian Arusha during rain season of 2006/07. Yield differences between moisture regimes were significantly (p < 0.001) different. Optimal moisture regime had the highest mean grain yield (1.49t/ha) followed by flowering stress (1.15t/ha) while pre flowering stress had the least mean grain yield (0.9t/ha). Correlation studies revealed that grain yield was related to number of days to anthesis, number of ears per plant, plant height, ear height, and leaf senescence. Of these, plant height, ear height, and number of ears per plant were consistently positively correlated with grain yield in all moisture regimes. Days to anthesis had varying correlations with grain yield depending on moisture conditions. Based on index values, entries 1 (EEQPMOPV-l-EA-#), 6 (EEQPM-13-EA半),10 (EEQPM- 34-EA-#), 13(EEQPM-45-EA-#), 14(EEQPM-49-EA-#), 19(POOL15QPM-SR-#-#) and 21 (Local check 1) performed better in most traits associated with drought. Grain yield, numbers of ears per plant, days to anthesis and leaf senescence were important selection criteria under drought but only grain yield and leaf senescence were important under both stress and optimal moisture conditions. Nine entries had above average yield and out of these only 3 i.e. 13(EEQPM-45-EA-#), 19 (POOL15QPM- SR-#-#) and 21 (Local Check 1) had stable performance across moisture regimes. Stable and high yielding genotypes should be evaluated under field conditions in the target environments so that farmers can select suitable genotypes to be proposed for release. Molecular characterization should be carried out to ascertain the degree of diversity available among the entries identified as best in different moisture regimes.