Crop Science and Production Collection

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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.
Effects of rate and time of nitrogen application on growth, leaf nutrient contents and yield of sugarcane at Kilombero Sugar Estates
(Sokoine University of Agriculture, 1985) Mkelenda, Abdallah Salum
ABSTRACT A field study on the effects of rate and time of nitrogen fertilization on growth, leaf nutrient contents and yield of sugarcane (Saccharum officinarum) variety N. Co.376 was conducted at Kilombero Sugar Estates in Morogoro region during the 198?/83 cropping season*Four rates of N and three different times of application were tested in factorial combination in a randomized block design using a plantcane crop*The IT rates were 0, 100, 200 and 300 kg 10xa applied as ammonium sulphate * The times of application were (i) all the N applied at planting, (ii) all the N applied at three months, and (ill) N applied in two split doses: one half at planting, and the rest at three monthd* The crop was grown for twelve months.The germination, stalk population counts, and the heights of the plants were determined.The N, 2?, K, Ca and Mg nutrition of the crop were assessed by analysing cane leaves sampled from two—and four-montha old plants* The yield and quality of the crop were determined at harvest time.The germination was good and was not affected by the treatments* Nitrogen fertilization increased stalk population, and cane growth significantly. Nitrogen application increased the concentration of N in the leaves sampled at the two ages, For the two months samples the leaf N concentration ranged from 1.87% to 2.29%, while for the four months samples the concentration ranged from 1,38% to 1.94%. Leaf N concentrations in the four months old plants were highly correlated with sucrose contents in the plants,. cane yield, and sugar yield. suggesting that leaf IT concentration could be used in predicting these parameters. Using a curvelinear relationship between leaf IT concentration and sugar yield a tentative critical N concentration of 1,78% was established.The concentrations of P, K, Ca, and Mg were considered to be within the adequate range for the crop. All rates of IT increased cane yield significantly but sugar yield increased with increase in applied N only up to 100 kg N/ha, Further increase in N did not cause further increase in sugar yield:'mainly because of the negative effect of higher rates of N on sucrose accumulation in cane plants. In addition, nitrogen application reduced the quality of the juice; i.e. the brix, pol and juice purity.Time of application did not have any significant effect on any of these parameters.The results of the study suggest that the optimum rate of IT for sugar production in Ruaha area of Msolwa Estate is around 100 kg 10ia and that all the IT can be applied in the furrows at planting. Also leaf analysis technique can be used for assessing the sufficiency of IT in cane plants.
Matemu, Liberatus John Hamis
(Sokoine University of Agriculture, 1987) Matemu, Liberatus John Hamis
ABSTRACT A field experiment was conducted at the Sokoine University of Agriculture experimental Farm to study plant-water status and grain yield of sorghum (Sorghum bicolor (L.) Moench) in relation to soil-water status.The treatments consisted of two soils, one having high water holding capacity (soil 1), the other with a low water holding capacity (soil 2); and two sorghum cultivars namely, Serena (improved) and Mbangala (local) under two moisture regimes of limited irrigation and rainfed conditions. Leaf water potential (kj'O and weighted soil-matric potential were measured to assess the water status for the plant and soils, respectively. Other observa-tions made were plant height, stem diameter, number of leaves, leaf area index (LAI), root length density, dry matter (DM) and grain yields as well as total water use efficiency (TWUE) and irrigation water use (IWUE).Plants growing in soil 1 showed higher than those in soil 2 throughout the measurement period.Mbangala maintained a higher than Serena with values of -5.42 and -7.51 bars respectively.plants had higher The irrigated than those under rainfed conditions.The weighted matric potential,soil 2 than in soil 1. The averages for the entire was lower in season were -0.29 and -0.38 bars for soils 1 and 2,respectively.The plots planted with Mbangala showed a lower l’pthan those with Serena their values being -0.34 and -0.33 bar^ , respectively.The weighted soil matric potential was lower under irrigated thanu.nc[er rainfed conditions.The differences under rainfed and irrigated conditions were larger in soil 1 than in soil 2.Soils did not show any significant difference in stem diameter at 56 days after planting (dap) despite the consistent trend observed whereby soil 1 produced plants with greater diameter than soil 2.significantly (P Serena. Mbangala showed 0.05) greater stem diameter than While stem diameter of Serena averaged 1.88cm, that of Mbangala was 2.10cm. Moisture regime had no effect on stem diameter. Soil 1 produced significantly (P ^_0.05) taller plants than soil 2.Plant height in soil 1 exceeded that in soil 2 by 24.5cm.Cultivar and moisture regimes as well as their interactions were non-significant..However, the interaction between soil X cultivar was highly significant (P ,0.01) .Both cultivars were taller (although not significantly so) in soil 1 than in soil 2. On the other hand, both cultivars showed consistently greater plant height under irrigated than rainfed conditions although the differences were non significant.Plants growing in soil 1 were observed to have a significantly (P.
Effects of cutting interval and nitrogen fertilizer rate on the yield and nutritive value of Brachiaria brizantha and Chloris gayana.
(Sokoine University of Agriculture, 1990) Mtengeti, Ephraim Joseph
The effects of three cutting intervals (20, 40 and 60 days ) and four levels of N application (0, 100, 200 and 400 kg N/ha) on the dry matter yield, dry matter content, tiller height, CP content, CP yield, N utilization efficiency, in vitro dry matter digestibility and in vitro digestible dry matter yield were studied in Chloris gayana and Brachiaria brizantha over a period of 120 days in 1987 in a field experiment at Sokoine University of Agriculture farm in Tanzania. The dry matter yield of the grasses increased with extension of the cutting interval up to 40 days and then declined thereafter. dry matter yield of the grasses increased with increasing N rate.The dry matter content increased with increasing cutting interval decreased with increasing N rate.The green leaf and stem dry matter yields increased with increasing N rate.Extended period between successive cuts slightly reduced green leaf dry matter yield and slightly increased the the stem dry matter yield. Leaf:stem ratio was not significant!;. ( P > 0.05) affected by extension of the cutting interval. Tiller height increased significantly (P < 0.01) with increasing N rate and cutting interval.The CP concent of the herbage decreased with extension of the cutting interval. The 'CP yield increased with increasing N rate and extension of the cutting interval to 40 days and declined thereafter.The recovery of applied N increased with increasing N rate up to 200 kg N/ha then declined thereafter.yield response in terms of kg DM Dry matter per kg of applied N decreased with increasing N rate.In vitro dry matter digestibility of the grasses increased with increasing N rate and decreased with extension of the cutting interval.Brachiaria brizantha had a significantly (P < 0.01) higher in vitro dry matter digestibility than Chloris gayana at all cutting intervals.The in vitro digestible dry matter yield of the grasses increased with nitrogen rate. It also increased with extension of the cutting interval up to 40 days and then declined thereafter. The results of this experiment support the view that, the productivity of grasses can be improved by N fertilization. In this study it has been shown that B. brizantha and C. gayana should be harvested every 40 days during the period of favourable growth in order to balance the productivity and the quality of the produced herbage.
Decomposition of crotalaria and leucaena green manures and their nutrient release patterns
(Sokoine University of Agriculture, 1992) Nikokwe, Chais Adam
The decomposition of Crotalaria and ochroleuca Leucaena leucocephala green manures. contained in litter bags and placed on the surface (8- 10 cm), was The study was or buried 12 weeks of incubation. studied during conducted under laboratory conditions determine and compare decomposition and patterns of the two of green manure subsequent nutrient in soil microbial determined and the release was manure residual nutrient release Changes investigated numbers with and decomposition on application to green manures. The effect of method related into the soil to decomposition. materials, and were time incubation Analyses of counting microbial were done at three week intervals. The rate of decomposition was expressed dry matter. organic carbon phosphorus in parameters the in terms of total nitrogen and residual material organic. All these were expressed as percentages of the original quantities added through the manure. Generally six weeks decomposition was fast during the first of incubation and slowed down thereafter rate of decomposition was similar in and decomposed by almost 50 and weeks of incubation, respectively. The both green manures, 70% after in six and 12 addition they had incorporated manure soil releasing capacities. However similar nutrient more decomposed faster and released nutrients than surface-applied. In treated microbial numbers incubation after The soil there during rapid were the first which populations soil-incorporated green microbial numbers than increases in weeks of six almost levelled off. manure resulted in the surface-applied one. Larger In the control soil such changes were small. From the that when results of used the this study two green it was manures z incorporated into the soil at least six period when the intended nutrients. crop has This will allow speculated should be weeks before the its maximum need for synchronization of maximum nutrient release with high nutrient demand by the crop.
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.
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%.
Use of fresh sugar cane crush as an additive for grass silage
(Sokoine University of Agriculture, 1998) Kavana, Pius Yoram
A study comprising of two experiments was conducted to investigate the effectiveness of Fresh Sugar Cane Crush (FSCC) as water soluble carbohydrate (WSC) additive for napier (JPennisetum purpureum) and guatemala (Tripsacum laxuni) grasses silage making. Polyvinyl chloride (PVC) pipes of average 1.9 X 1(J2M3 were used as laboratory silos for experiment I and earth pit silos (7.5 x lO^M’)for experiment II. The second experiment was conducted so as to mimic the field condition as well as to produce enough silage for acceptability test by dairy heifers. The effect of grass species and additives were observed in both experiments while the effect of wilting was observed in the first experiment only. In both experiments five treatments comprised of T1 - no additive (control), T2 - 5 % molasses, T3 - 5 % FSCC, T4 - 10 % FSCC, T5 - 15 % FSCC were used to test the effectiveness of FSCC as a WSC additive in grass silage making. Parameters observed were chemical composition, fermentation products, sensoric tests and in- vitro dry matter digestibility (IVDMD). Dry matter losses and acceptability test were observed in the second experiment. The data were analyzed by General linear model system of SAS (1988). In the first experiment, there was no significant (P > 0.05) difference between unwilted and wilted napier silages in terms of DM contents. Wilted guatemala silage had significantly ( P < 0.05) higher DM contents than unwilted guatemala silage. In napier silage, wilting resulted into higher WSC (16.7 vs 15.0 gkg"DM), IVDMD (59.9 vs 58.7 %), pH (4.02 vs 3.89), ammonia nitrogen (3.4 vs 2.5 %) and lower lactic acid (15.3 vs 17.5 gkg"DM). In guatemala grass silage,wilting resulted into higher WSC (20.4 vs 14.2 gkg』DM), ammonia nitrogen (3.8 vs 2.9 %), lactic acid (18.4 vs 13.5 gkg-lDM), butyric acid (1.2 vs 0.6 gkg-1DM) and lower IVDMD (60.7 vs 62.2).The pH between wilted and unwilted guatemala grass silages were not significantly different (P > 0.05). The DM contents were significantly different (P V 0.05) between treatments in unwilted napier and wilted guatemala grass silages. For both napier and guatemala grass silages, pH ranged from 3.78 in T5 for unwilted guatemala to 4.5 in T1 for wilted napier. Lactic acid ranged from 3.6 in T1 wilted guatemala to 27.4 gkglDM in T5 unwilted napier. Ammonia nitrogen was lowest (2.3 %) in T5 wilted guatemala and highest (4.6 %) in T1 wilted guatemala. Regardless of wilting DM, WSC, IVDMD, ammonia nitrogen, and butyric acid were significantly (P V 0.05) higher in guatemala silage than in napier silage. The pH and lactic acid contents of napier and guatemala silages were not significantly (P > 0.05) different. In experiment two, the DM contents were significantly (P V 0.001) different between treatments in guatemala silage and the percentage DM loss ranged from 16.1 in T5 to 39.1 % in Tl. In napier silage the DM loss was highest (32.9 %) in T2 and lowest (13.7 %) in T3. In guatemala silage the intake rate between treatments ranged from 14.6 in T4 to 31.2 gDM/min in T2. In napier silage the intake rate ranged from 29.1 in T2 to 41.6 gDM/min in T4. Both napier and guatemala silages showed significant (P V 0.05) difference between treatments in terms of WSC and IVDMD. In napier silage, the control treatment had highest pH (4.34), ammonia nitrogen (3.9 %) and lower lactic acid (7.9 gkg4DM).Butyric acid was not detected in napier silages. In guatemala silage, the control treatment showed the highest pH (4.54), Ammonia nitrogen (3.1 %), butyric acid (3.0 gkg'DM) and lowest lactic acid (7.3 gkg4DM). There were no significant differences between napier and guatemala silages in terms of DM, IVDMD and ammonia nitrogen. The WSC contents and intake rate were higher in napier than in guatemala silage.The percentage DM loss, pH, lactic acid and acetic acid content were significantly (P V 0.05) higher in guatemala than in napier silage. It was concluded that 5% FSCC and 10% FSCC could be used to conserve well silages of guatemala and napier grasses, respectively. Further findings are required to establish the levels of inclusion of FSCC in other common grasses such as Panicum maximum and Setaria splendida.
Paths of influence among components of yield in sorghum (Sorghum bicolor (L) Moench, cv Tegemeo) grown in the semi arid area of Dodoma Region, Tanzania
(1998) Reuben, S.O.W.; Rwehumblza, F.B.R.; Mahoo, H.F.; Hatibu, N.; Makungu, P.; Ashimogo, G.C.
Sorghum is a food security crop in tropical marginal areas. Improvement strategies for yield under such conditions are important. Genetic improvement for yield is done thr0ll:gh improvement of its components. Due to yield component compensation, this improvement strategy is made less rewarding. It is therefore important to know compe1J.satory mechanisms existing for better improvement strategies. Studies on the nature of component compensations in sorghum are limited and virtually lacking under Tanzanian conditions. A field experiment was conducted to investigate the nature of interrelationships among components of yield in sorghum at the experimental plots of Hombolo Research Station in the semi-arid zone of Dodoma Region, Tanzania. Six treatment combinations, of rain water harvesting techniques and fertilizer were laid out in a randomized comple,te block design (ReED) with four replications during the growing season of 1996/97. Number of grains was an important component which was significantly correlated (r=O. 982***) with grain yield and had a high positive direct effect (0.979) on yield. Average grain weight was not import~nt in influencing yield of sorghum. Plant biomass had a negative direct effect (-1.2997) on average grain weight but was not important in influencing number of grains. Plant height and percent light intercepted directly influenced number of grains and average grain weight negatively. The negative influence (- 0.8712) of plant height on number of grains was compensated to a low relationship (r= -0.337) mainly by its positive indirect influence (0.3780) through light interception. Improvement strategies should aim at shorter plants with more grains, of lesser canopy development and biomass in these semi arid areas.
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.
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.
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.
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.
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.
Response of three common bean (phaseolus vulgaris l.) varieties to moisture stress at different levels of phosphorus.
(Sokoine University of Agriculture, 2008) Ndomondo,Martin Ernest
In this study, two experiments were conducted, one (field experiment) at the Horticultural Unit of the Sokoine University of Agriculture (SUA) located at 6° 5’ S 37° 39’ E with an elevation of 524 m a.s.l. and the other (pot experiment) was conducted at the screen house of the Department of Crop Science and Production.The main objective was to study the response of the three common bean varieties i.e. SUA 90, Kablanketi and Canadian wonder, to the interaction of the two factors; moisture stress and different levels of phosphorus fertilizer. The source of phosphorus used was Triple Super Phosphate (TSP) and the source of water used for irrigation was tap water for the pot experiment and rain for the field experiment.Three levels of phosphorus used were 0 kgP/ha, 30 kgP/ha and 60 kgP/ha. The three moisture regimes applied were less than 21 cb, between 21 and 50 cb and between 51 and 60 cb of moisture tension in the soil. In Canadian wonder total plant biomass significantly increased with increasing P. Root biomass increased with increasing P application in SUA 90. From this study it was concluded that Canadian wonder is the most vigorous and tolerant variety of the three, it has a vigorous growth which enables it to tolerate low P and moisture stress. It was hence recommended that, common bean breeders should use this variety in breeding for tolerance to moisture stress and low P.
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 for 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-#), 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.
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.
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.
Seasonal variations of nematode infection in Small East African goats and their crosses with Boer and Saanen reared under extensive and semi- intensive systems
(2010-04) Muhikambele, Vedasto; Chenyambuga, Sebastian; Mbaga, Said
A study was conducted in Turiani (sub-humid environment) and Mlali (semi-arid environment) to assess the seasonal variation of nematode infection in Small East African (SEA) goats and F 1 crosses of SAE with Saanen and Boer. The SEA goats were kept under extensive system while the crossbreds were kept under semi-intensive system. In Mlali 37 SEA goats and 30 SEA x Boer crosses while in Turiani 30 SEA goats and 33 SEA x Saanen crosses were included in the study. Worm burden was assessed using faecal egg count (FEC) and packed cell volume (PCV) as indicator traits. Faecal and blood samples were collected at the end of dry season, mid and end of rain season. The dominant worm species were identified by faecal culture. The results indicated that fewer animals (30 – 66.7%) were infected at the end of the dry season than at the mid and end of the rain season (69.7 – 100%). The FEC values differed significantly between periods of the year (P< 0.001) and between locations (P<0.05). The geometric mean faecal egg count (GFEC) ranged from 71.3 to 200.9, 185.8 to 516.4 and 273.5 to 924.7 eggs per gram (epg) at the end of dry season, mid and end of rain season, respectively. The GFEC values of SEA goats reared under extensive system were slightly higher (80.5 – 924.7 epg) than those of crossbred goats (71.3 – 690.2 epg) reared under semi-intensive system. The PCV values differed significantly (P<0.001) between locations, periods of the year and breeds. In Mlali, the PCV values ranged from 18 to 45% while in Turiani, the values ranged from 10 to 43%. The dominant parasite in the study areas was Haemonchus spp and accounted for 47.5 and 48.9% of total worms in Turiani and Mlali, respectively. This was followed by Trichostrongylus spp (21.3 and 19.8% in Mlali and Turiani, respectively) and Oesophagostomum spp (18.2 and 20.7% in Turiani and Mlali, respectively). The proportions of Strongyloides spp (6%), Bunostomum spp (4%) and Cooperia spp (3%) were small in all periods and locations. It is concluded that the level of nematode infection is highest at the end of the rain season and low during the dry season. The crossbred goats kept under semi-intensive grazing system had lower level of nematode infection than the local goats kept under the free-range grazing system
Assessment and management of post harvest losses of fresh mango under small-scale business in Morogoro, Tanzania
(JAPS, 2011) Msogoya, T. J.; Kimaro, E. S.
This study was conducted to assess postharvest losses and the effect of shade during wholesale market and hot water treatments on storage of mango cv. ‘Dodo’. To assess postharvest losses, mature fruits were packed on semi-rigid bamboo cartons, loaded on a truck without separators in between cartons and transported from Mkuyuni ward to Morogoro urban, Tanzania. The effect of heat stress during the wholesale market was evaluated by storing mango fruits under the sun, woven polypropylene shade and black net shade at Sokoine University of Agriculture. Mango fruits dipped in hot water at 60° C for 10 minutes were compared with untreated ones as control. Results showed that the fruit total postharvest losses were 43.8 % with the wholesale market, transport and harvest stages accounting for 30.6 %, 10.6 and 2.6 % of the total losses, respectively. The main features of fruit deterioration during the wholesale market stage were softening and microbial decay each accounting for 50.7 and 39.6 % of the total losses within the stage, respectively. Microbial decays of 7.2 % and mechanical injuries of 2.0 % were the major features of mango fruit deterioration during the transport and harvest stages. Storing fruits for three days under the woven polypropylene and black net shades significantly reduced fruit postharvest losses by 52.7 and 38 %, respectively in comparison with fruit storage under the sun. Hot water treatment reduced the incidence of microbial decay by 85 % and improved fruit total soluble solids content by 15 % in comparison to untreated fruits. However, hot water treatment reduced fruit firmness and shelflife by 56.0 and 71.4 %, respectively. In the short term, wholesale traders are advised to store fruits under the polypropylene shade while in the long term, municipal and council authorities are argued to construct cold storage facilities for fresh fruits. Furthermore, farmers are advised to disinfect mangoes with hot water, especially those purported for immediate marketing.

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