Theses and Dissertations Collection

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Influence of cluster number and spacing on set, growth, yield and quality of early fruit of the fwest virginia ‘63’ tomato lycopersicon esculentum (mill.)
(Sokoine Universty of Agriculture, 1974) Mnzava, Nameus Abel
Most commercial tomato lines exhibit a pronounced indeterminate growth habit on the main and lateral vegetative axes and weakly on the raceme. Due to this, their culture has been associated with high material and labor requirements, earliness is usually delayed and unharvested crop is high in regions with short growing seasons. Current emphasis for processing types is to attain a once-over destructive harvest made nearly efficient by determinate cultivars. Despite the large genetic reservoir available to breeders for such ideotypes suitable for mechanical harvestlngf it may be a long time (Massey ejt al. (40)) before optimum combinations of physical cha rac ter is t ic s of fruit and vine combined with high processing quality are found• Current indeterminate cultivars produce fruit of excellent horticultural quality. If we are to operate with these, their pattern of vine growth, therefore, requires physical alteration as a logical alternative.
Coffee in the economy of Tanzania and the implications of membership In the international coffee agreement
(1979) Msuya, M. Michael
We seek in this work to develop recommendations for policies that will enable Tanzania to enhance her gains from trade in coffee, in of the changing environment O’- orally. in the world coffee and economic scene We start in the first chapter with an introduction to the O/j^anian economy and identification of the place of coffee in this - z/r-omy. In the second chapter we review literature relating to the structure of the international coffee market, the commodity problem and justification for international market intervention in the form of the International Coffee Agreement (ICA). The third chapter is an attempt to assess, empirically, the effectiveness of the ICA on Tanzania’s gains, defined in terms of the agreement’s objectives as increased stability and progressively increasing trend in the real value and purchasing power of income derived from trade in coffee. We devote chapter four to a review of Tanzania’s fortunes in the ICA and the trends in world coffee production and consumption. Finally, in chapter five we review ongoing coffee programs and practices in Tanzania and develop the said policy recommendations based on the country’s experience as well as the current and expected market environ ment . Two sets of factors determine the extent to which Tanzania gains from its involvement in the world trade in coffee. First is the group of factors which, for purposes of the present study, we term endogenous factors. Within this group fall such factors as production policies, quality controls and management efficiency, all 1.2. of which factors are largely a function of voluntary actions of agents within the country’s economy. These factors could be government, industry, or grower-determined or - effected. The distinguishing trait is that they are to a large degree within the willful control of agents within the country’s economy. Distinct from this category of tors is the second set of factors, which we refer to as exogenous factors. In this category we include all factors, geographically domestic jr foreign to Tanzania, that are largely beyond the willful control of agents within the country’s economy. Under this category fall such factors as market prices, export quotas, changes in consumer demand and adverse weather conditions (be they domestic or foreign to the country). This second set of factors is further sub-divided into: (a) Exogenous factors that originate from man-made decisions and as such are subject to negotiations within the ICA or other multi lateral or bilateral framework, as would, for example, be the case with coffee export quotas within the ICA, and preferential market arrange ments between the European Economic Community (EEC) and the associated African countries, of which Tanzania is one. (b) Exogenous factors that originate from man-made decisions but whose occurrence is not negotiable. In this category are included such factors as changes in consumer demand, long-term changes in world production patterns, and technological advances affecting either or both production and consumption. (c) Phenomenal occurrences that may have their origins in man-3- made decisions or natural circumstances. Examples of these occurrences include extreme weather conditions such as serious frosts in Brazil, extreme monetary instability such as occurred at the beginning of this decide, and labor strikes affecting a major aspect of the world coffee - omy such as an extended longshoreman strike in major United SlsgU-.es coffee ports of entry. Before we start the intended discussion and analyses of the factors of concern in the present study, it is in order to outline some aspects of the historical and structural background to the Tanzanian economy and the way in which coffee and the commodity’s world trade fit into this economic framework. That is the subject of the first chapter.
Specific problems in agriculture most in need of research solutions as perceived by west virginia vocational agriculture teachers and county extension agents
(West Virginia University, 1982) Chalamira, Lucas Ralph
Objective The primary objective of the study was to identify specific prob- lems in agriculture which are most in need of research solutions as perceived by West Virginia vocational agriculture teachers and county extension agents. Methods and Procedures Data for the study were obtained from the study population con sisting of 106 vocational agriculture teachers and 48 county extension agents.The Delphi technique consisting of two types of questionnaires was used.The first phase questionnaires asked participants to list five specific agricultural problems in their communities which, in their opinion, were most in need of research solutions. Responses were then used by the Q-sort committee to formulate 136 rateable state- ments which formed the second phase questionnaire. were sent to the same study population. The questionnaires The response was 75 percent. Data were analyzed using West Virginia University computer facilities. Means and standard deviation were determined for each statement by category, position and region. Findings Information derived from the study reveals that there are many agricultural problems in West Virginia which seriously need research attention. Problems identified by the respondent groups cut across all the major areas of the agricultural industry: field crop production; livestock production; horticulture; farm management; plant pests/ diseases; pasture management; agricultural marketing and processing; farm machinery and structures; soil/water conservation; agricultural energy; and rural development and extension/education. Of the 136 problems identified by participants, 19 were rated as "very important". Considered particularly serious were: multiflora rose eradication; coping with high production costs and interest rates; and improving state level funding for extension and vocational agri culture programs. The study also showed that vocational agriculture teachers and county extension agents had similar perceptions of many of the problems identi fied. However, problems connected with vocational agriculture programs were rated higher by vocational agriculture teachers than by county extension agents. The degree of importance of the problems varied from region to region. These regional variations may be due to the fact that different parts of the state have different geophysical and climatic conditions. However, problems associated with livestock (and particularly beef/ dairy) and pasture production were similar in all the six regions of the state. It was recommended that research institutions in West Virginia study the problems identified and take them into consideration when evaluating/developing research programs. also be taken into account. Regional variations should
Structural change in the U.S. soybean and soybean products markets: a systematic varying coefficient simultaneous system approach
(University of Illinois, 1985) Rugambisa, Jeremiah Boniface Ishengoma
The soybean industry is an interesting area for investiga- It is extremely complex and has been changing rather t ion. dramatically over the last 10 to 15 years. There exists a high degree of interaction among the markets for soybeans, oil and soybean meal. soybean Recent shocks and changes in the world economic environment have impacted substantially on the industry altering the demand for its products and even changing the participants and their roles in the marketplace.
EFfects ob’ progressive edible le a f h nd tuber removal on yield and development of two d : j ..«. I J J purpose sweet pot a to (Ipomoea batatas (L.) Lam.) cultivars
(Sokoine Univesirty of Agricuture, 1986) Teri, Florence J.
Two dual purpose sweet potato (Ipomoea batatas (L) Lain.) cultivars "Bangi" and "Simama" differing in shoot morphology were subjected to differential leaf and tuber harvest combination under field conditions at Morogoro. The aim was to find out the effect of leaf and tuber harvesting combinations on tuberous and edible leaf yield, plant development and the adaptability of the cultivars to two tuber harvesting methods. Either edible leaves, edible tubers or both leaves and tubers were progressively removed. The control treatment consisted of a single final tuber harvesting without leaf or tuber removal. Leaf and tuber harvesting treatments were imposed monthly commencing at 77 and 99 days from planting respectively. Sample plants for the determination of dry matter distribution with time in leaves, stems and roots were taken three times at monthly intervals starting at 75 days from planting. The erectophile cv '’Simama" gave a significantly higher total yield (4.4 t/ha) and fresh edible leaves (1.09 t/ha) over the procumbent cv '’Bangi”. In cv "Bangi'’ progressive removal of both leaves and tubers gave 2.6 t/ha tubers above control and 0.6 t/ha above(iv) control where only tubers were progressively harvested. Progressive removal of leaves in cv "Bangi” had 2.4 t/ha below control. In cv "Simama” progressive harvesting of both tubers and leaves gave 1.8 t/ha fresh tubers above control and 1.5 t/ha above control where only tubers were progressively removed. Where only leaves were progressively (harvested, tuber yields were 0.6 t/ha above control. Progressive harvesting of both tubers and leaves yielded 3.1 t/ha fresh tubers more in cv "Simama” than cv "Bangi" and 1.04 t/ha fresh edible leaves. P.emoval of leaves resulted in an increase of 6.9 t/ha fresh tubers and 1.4 t/ha edible leaves in cv ’’Simama’’ over cv ’’Bangi”. In plants where only tubers were removed cv "Simama” had 3.6 t/ha over cv ’’Bangi". The progressive method of tuber harvesting had an overall higher tuberous yield compared to single method but the number of pig tubers was high. During the first 10 weeks of growth, per cent dry matter distribution in leaves was about 50 of the total plant dry matter in all the treatments. But 15 weeks later dry matter in roots had increased to an average of 34.1 per cent. Nineteen weeks after planting the proportion of dry matter in roots was significantly(V) higher than that in leaves or stem. Final dry matter distribution in roots was higher in the treatments whose tubers were harvested once in both cultivars. Leaf picking affected the performance of cv "Bangi" but not cv "Simama”. Combination of progressive removal of both leaves and tubers gave highest fresh tuber yield in both cultivars. Sink rather than source seem to be more important in sweet potato yield, but the performance of the two cultivars showed that a good source is also important.
Plant-water status and grain yield of sorghum (sorghum bico1or (l.) moench) in relation to soil water status at Morogoro, Tanzania.
(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.
Reproductive efficiency traits and viability of calves of Mpwapwa cattle and their crosses
(Sokoine University of Agriculture, 1988) Das, Shoshinder Sachindra Manmohan
Fifteen years data on reproductive traits and viability of calves were analysed. Data were collected from cattle records at Livestock Production Research Institute, Mpwapwa, in Central Tanzania. The reproductive traits studied were age at first calving, calving interval (CI), dry period (DP), days open and conception rate (CR)., The genetic groups in the study were Mpwapwa, F^-crossline and Backcross having 8.0%, 54.0% and 31.0% Bos taurus genetic propor- tion, respectively. The objectives of the study were to evaluate the influence of genetic and environmental factors on reproductive traits and viability of calves, to estimate repeatabilities for reproductive efficiency traits (CI, DP and days open) and to .evaluate the relationship between reproductive traits and milk production traits. Overall mean age
Etiology and control of stem rot of sunflower (helianthus animus l.)
(Sokoine University Of Agriculture, 1988) Bujulu, Joel
Surveys were curried out on the distribution in Tanzania of a new sunflower disease first observed in Morogoro Region. Experiments were conducted at the Tropical Pesticides Research Institute (T.P.R.I.) ana Sokoine University of Agriculture (SUA) to identify the causal agents, assess their pathogenicity to sunflower varieties commonly grown in Tanzania and other crops normally grown in association with sunt lower, and to determine biological activity of some selected fungicides to the disease causing organisms. Out of all eight surveyed regions, sunflower stem rot was confirmed only in Morogoro region. Fusarium moni liforme She Id and F. graminearum Schwabe were identified as the causal organisms inciting the new sunflower disease which was later named "sunflower stem rot". Sunflower- varieties namely Record, Jupiter, Gor 104 and Dwarf comet were found less affected by both Fusarium spp. while Giant 549, IS 894, IS 894 amd 6F5 were more susceptible. Groundnuts, simsim. cowpeas and greengram did not show symptoms upon artificial inoculations with the two Fusarium spp. while maize, sorghum, beans and garden peas showed necrotic symptoms in the areas inoculated. The fungicides Sisthane (fenapanil) and Ridomil (metalaxyl) were not effective against both fungi in laboratory culture tests while Benlate (benomyl) was effective. But Benlate proved inffective in controlling the disease in the field during field tests.iv Severity of sunflower stem rot was more apparent in fields planted a t ve ry close spacing whether it was a monoculture or interplanted with other crops resulting in more plant deaths. It is recommended that sunflower varieties which were found resistant be distributed to peasants in Morogoro Region and that only resistant ij Ten r. .1 be used in crops like groundnuts, simsim, cowpeas intercrop u- f lower and all other Wherever stem rot is endt intercrops should be planted at w’^nr tpacin which favour disease development. . *“het particularly on breeding for more ■e •’void overcrowding ”C se.i <_«> is being suggested t« nt van The suitability of fungicide «_or.- : -I cf .> s. in peasant grown sunflower appears remote an<" .‘:urrLe«r ;.r /e i.^vxuns on this aspect sl.nould be on large farms
Effects of intercropping and plant density on growth, development and yield of pigeonpeas (cajanus cajan (l.) millsp.) and maize (zea mays l.). under semi- arid conditions of Kenya
(University of Nairobi, 1988) Rwamugira, Winifrida Kokuhirwa
In semi-arid areas of Kenya 95% and 70% of pigeonpeas and maize, respectively are intercropped This study was designed to determine the annually. effects of intercropping pigeonpeas and maize at variable plant densities and also to determine the appropriate intercropping ratio or combination for optimum economic yield. Two pigeonpea cultivars were intercropped with Katumani maize at three plant densities in Ka- bete, Thika and Kiboko during the 1986/87 cropping season. The experimental design was a split-split plot with three replications at each location. Re sults indicated that intercropping and plant density reduced leaf area and shoot dry weight of both pi- geonpeas and maize. Plant height of pigeonpeas was reduced by intercropping while that of maize was increased. In pigeonpeas number of mature pods and grain yield per plant were reduced by both inter cropping and high plant density. Reduction in 100 seed weight varied with location suggesting an en vironmental influence. For maize, number of cobs and grain yield per plant were also reduced by intercropping and high plant density. Generally, yield per hectare of a species in intercrop was lower than in monocrop, but total yield of intercrops (pigeonpea + maize) gave higher yield ad vantage over monocrops. Land equivalent ratio (LER) values indicated that all intercrop ratios were superior to monocropping. At all the experimental sites best in tercrop combination was attained when a row of pigeonpea alternated with a .row of maize. spacing, of 105 cm.
The incidence, economic importance and control of aphelenchoides Besseyi Christie 1942 on rice
(Sokoine University of Agriculture, 1989) Gata, Ntombana R.
The distribution, control Aphelenchoides besseyi Christie and 1942 economic on rice importance sativa L) (Oryza cultivars grown in mainland Tanzania was studied. Survey results showed that A. besseyi was widely distributed in stored rice seeds. Hot water treatment (HWT) of dry rice seeds at 54 - 62°C for In dry seed 15 min effectively controlled seed-borne A. besseyi treatment, exposure period rather than treatment temperature was the significant factor for the control of seed-borne A. besseyi. Tested seeds of rice cultivars tolerated dry seed treatment upto 60 0 C' for 20 min in respect of viability, vigour and seedling normality. Seed treatment at 54°C controlled A. besseyi for but also 15 min following affected. The sensitivity presoaked rice seeds to HWT was genetically related following presoaking percentage germination delayed onset, vigour viability, seedling normality of some rice cultivars and of Seeds treated maximum peak, presoaking and actual Although HWT of presoaked seeds at 56°C for 15 min completely controlled A. besseyi, it also killed most seeds. However, HWT of presoaked or unsoaked seeds at 48°C for 20 min did not affect seed germination and emergence. Significant control of seed-borne A. besseyi by HWT following presoaking resulted in 10 - 27% yield increases and, larger and/or better quality grains. Booting stage of rice was the critical stage for control of A. besseyi for improvement of yield. The fifth day after the first sign of booting was identified as the most infection with A. besseyi to adversely critical affect yield stage for attributes.iii Control of A. besseyi with carbofuran applied at planting and at 50% booting stage improved rice yield but HWT of A. besseyi-infested rice seed gave better nematode control and better grain yield. Dry seed treatment to control seed-borne found to be the most appropriate method because it environment is effective, cheap and safe for to A besseyi Tanzanian the was farmers; seed and the environment
Plant structure in relation to ease of physical breakdown in the mouth and rumen
(University of Wales, 1993-09) Mtengeti, Ephraim Joseph
Grassland species were grown in the field and glasshouse and research was carried out for two years to investigate plant vascular structure in relation to physical breakdown in the mouth and rumen. Plant part morphology, vascular structural proportion and arrangement, fresh plant diet eating rate by sheep and particle breakdown characteristics were recorded. Anatomical differences, especially vascular tissue arrangement, appeared to be a major cause of the differences in intake rate between legumes and grasses. Four legumes did not differ significantly in terms of intake rate but differed significantly in terms of the proportion of vascular tissues, neutral detergent fibre content and digestibility. Tropical grasses had a higher proportion of vascular tissues, higher neutral detergent fibre content, lower digestibility, lower intake rate and were chewed into smaller particles than temperate grasses. Legumes were eaten faster and had larger particles after chewing than grasses. Legume and grass particles had a similar number of perforations or ruptures per particle. Legume leaf petiole and stem particles were longer than leaflet particles and increased the overall mean particle length of the chewed material. Petioles and stems are, therefore, important in legume particle size reduction in the mouth and rumen. Regardless of grass species, the veins of the leaf sheaths were more widely spaced than those in leaf blades, but the two plant parts were chewed to a similar particle size. Despite having a high proportion of stem and neutral detergent fibre, lucerne and spurrey were eaten quickly, showing the advantage, in respect of intake rate, of having thin pliable and/or fragile stems. The results of the present project indicate that the physical structure of plants, especially the arrangement of the vascular tissue, and plant morphology have great influence on the physical breakdown of the plants in the mouth and rumen.
Etude de la ramification de deux cultivars d’Ananas (Ananas comosus (L.) MERR.); “Cayenne lisse” et “Queen victoria”, en relation avec leur developpement sous diverses conditions climatiques de Pile de la Reunion.
(University Henri Poincar6, 1996) Maerere, Amon Petro
Conservation of napier grass as silage by small holder dairy farmers in Tanzania
(Sokoine University of Agriculture, 1996) Maeda, Florence Elizabeth Henry
A 23 factorial experiment was conducted to investigate the best method of conserving napier grass as silage under small scale dairy fanners situation. Four irealinenis (methods) were imposed on the forage before it was ensiled in either earth pits or concrete silos, namely; T1 - 5cm chopped grass with 3% molasses. T2 - 5cm chopped grass without molasses, T3 - unchopped grass with 3% molasses and T4 - unchopped grass without molasses. The silage was sampled after 3 months, and analyzed for percentage DM losses, chemical composition, fermentation and sensoric qualities, fn vitro DM and OM digestibilities and DM degradability. The rate of silage intake in gDM/ minute was determined using six dairy heifers. Additionally, cost of producing the silage under each method were estimated in Tsh./kgDM of useftil silage. Both chopped and 3% molasses treated napier silage showed lower (P < 0.01 and P < 0.05, respectively) percentage DM losses as compared to unchopped and nnmolasscd silage. However, the DM losses did not differ significantly between the silo designs used. Chopped silage had more (P < 0.001 and P < 0.01) CP and WSC contents than unchopped silage. Also addition of 3% molasses significantly increased (P < 0.01 and P < 0.001) the CP and WSC composition of napier silage. The CP content however. was more resei-ved in napier silage produced in the earth pits than the concrete silos. The preservative quality of napier silage was highly (P< 0.001) improved by chopping and/ or addition of 3% molasses at ensiling. Lower pH (3.99 vs 4.64). NH3 - N (4.03 vs 6-37) and butyric acid concentration (2.6 vs 7.5 gkg'1 DM) and higher content of hiciic acid (37.3 vs 14.2 gkg'1 DM) and acetic acid (38.5 vs 21.8 gkg 1 DM) were observed in chopped than unchopped silage. Lower pH, NH3 - N and butyric acid(4 21 vs 4.43. 4.09 vs 6.31% and 3.8 vs 6.4 gkg'1 DM, respectively) were also observed in molasses treated compared to untreated silage, while lactic and acetic acid concentrations were significantly higher (36.8 vs 14.7 gkg'1 DM and 40.3 vs 20.1 gkg' DM, respectively). Additionally the sensoric scores were significantly (P< 0.001) better for chopped and/ or molasses treated napier silage. The condition which was more observed on silage made in the earth pit silos. Chopped silage had significantly higher (P < 0.001 and P < 0.01) In vitro DM and OM digestibility and In sacco DM degradability than unchopped sihige. Also rnolassed silage showed significantly higher (P < 0.001) In vitro DM and OM digestibility. There was a significant (P< 0.01 and P< 0.001) improvement in rate of silage intake when tlie animals were fed on pre - chopped and/ or molasses treated napier silage. however minor differences were observed for the silage made in either type of the silo. Economically, chopping and addition of molasses at ensiling produced napier silage at a least cost especially from the earth pit silos compared with other ensiling methods. It is concluded that, pre - chopping and addition of at least 3% molasses to napier grass at ensiling produced good quality silage. Also the technique can be more economical and technically feasible in short terms when plastic sheet covered earth pit silos are used rather than the concrete silos which have higher initial construction costs.
Quantifying the effects of temperature and photoperiod on phenological development to flowering in rice.
(Michigan State University, 1996-05-22) Yin, Xinyou
Accurate prediction of crop phenology is important not only for modelling purposes but alsofor crop improvement and management actions The objective of this study was to develop a Methods for predicting phonological development to flowering in rice (Oryza saliva L). from the literature were analysed to evaluate a basic equation for crop development. Beta function, commonly used as a skewed probability density function in statistics, was used if' accurately describe responses of rice development rate to both temperature and Controlled-environmcnt experiments were then conducted for detailed understanding of the physiological basis of photothermal responses of preflowering development in rice Effects of day and night temperature on development to flowering were found to be different The plants did not respond to photoperiod throughout the entire preflowering period, instead, the photoperiod-sensitive phase was sandwiched by two photoperiod-insensitive phases. It appeared that responses to both day and night temperature were stronger during the photoperiod-sensitive phase than during the two photoperiod-insensitive phases The results also indicated that leaf appearance occurring simultaneously during the preflowering development had a different thermal response from that of the development perse. Based on the experimental results, a detailed model for photothermal responses of flowering in rice was developed, using the Beta function The model, referred to as the three-stage Beta (3s-Bcta) model, describes different photothcrmal responses during the photoperiod-sensitive phase and the photoperiod-insensitive phases of preflowering ontogeny. Using parameter values derived from controlled-environmcnt experiments, the 3 s-Bet a model adequately predicted rice flowering dates observed in field conditions. It performed better than several existing models over a wide range of environments. In order to assist new plant type design, the 3s-Beta model was applied to determine optimal preflowering phenological traits of rice for an increased yield potential in three different irrigated environments in Asia. The results of this thesis were discussed in view of the experimental findings, the methodology of phenology modelling and model applications
Seed production, dry matter yield and nutritive value of two stylosanthes species as affected by fertilizer application and time of harvest at Morogoro.
(Sokoine University of Agriculture, 1997) Imamu, Abubeker Hassen
A study comprising two field experiments was conducted to examine the effects of nitrogen fertilizer application time and and phosphorus (N) harvest of (P) seed on production, dry matter (DM) yield and nutritive value of hamata Stylosanthes Stylosanthes and guianensis at Morogoro. Split-plot experimental design was used in the study. In experiment I, two levels of N (0 and 30 kg/ha) and two levels of P (0 and 3 0 kg/ha) were arranged factorially as a main-plot treatment. In experiment II, four levels of P (0, 30, 60, and 90 kg/ha) were applied with 30 kg N/ha as a main-plot treatment. In both experiments sub-plots were harvested at 50 % flowering stage, 4th , 5th , 6th and 7th week post 50 % flowering stage. The results showed that N application increased seed yield, DM yield and crude protein 67.3, 45.68 and (CP) % of S.hamata by 9.63 percent as compared to the control, respectively. N application also increased CP %, in vitro dry matter digestibility (IVDMD) %, in vitro organic matter digestibility content of (IVOMD) % S.guianensis andmetabolizable by4.44, 5.92, energy 3.64 and (ME) 3.59 percent over the control, respectively. However, the DM and seed yield of S.guianensis tended to decline with N application. Phosphorus fertilizer application on the other hand did not affect seed yield and DM yield of S.hamata. However, it increased the leaf:stem ratio, harvesting index and seed yield of S.guianensis. herbage produced declined in The over all quality of both species with P application in terms of digestibility and subsequently the ME content as compared to the control. Maximum return per Tanzanian Shilling (Tsh) invested on N was obtained from S.hamata kept for both seed and fodder production (12.02 Tsh) , followed by the same species kept for seed production alone (9.75 Tsh) . The maximum return per Tsh invested on P was obtained from S. guianensis kept for seed production alone (8.02 Tsh), followed by the same species kept for both seed and fodder production( 5.05 Tsh). In both S.hamata and S.guianensis increasing time of harvest increased harvesting index, seed yield and herbage DM yield. However, peak seed yield was not yet attained within the range of harvesting time considered for S.hamata while it was at the 6 th week for S.guianensis. In both Stylosanthes species ash %, CP %, and DCP content declined with increasing time of harvest. However, the acid detergent fibre (ADF) %, and acid detergent lignin (ADF) % in DM of the two species responded to increasing time of harvest differently. Both ADF and ADL % in DM increased in S.hamata and declined in S.guianensis with increasing age of the plant. This trend was reflected on the in vitro digestibility value of the feed which declined continuously in S. hama ta and increased after the 5ch week in S.guianensis. It was concluded that starter dose of N application enhanced seed production, DM yield and quality of the forage in S .hamata; where as S.guianensis benefited only in terms of quality improvement of the forage. Application of P was not beneficial under Morogoro condition for S.hamata while for S.guianensis, P application at the rate of 60 kg P/ha gave higher seed yield and quality forage than the rest of P levels tested. Large yield differences were observed between early Vs. late harvesting time in both S. hamata and S. guianensis in terms of seed yield, DM yield and quality of herbage produced. This preliminary work, therefore, suggested that harvesting time for optimum seed production should be at the 7th and 6 th week post 50
Root distribution and below ground interactions in alley cropping of calliandra calothyrsus and leucaena leucocephala with maize at embu, Kenya.
(Sokoine University of Agriculture, 1998) Njuki, Margaret. W.
A study was conducted to assess the root distribution of Leucaena leucocephala, Calliandra calothyrsus and Zea mays (maize) when intercropped and that of maize when monocropped. The effect of leucaena and calliandra prunings on maize was also evaluated both under monocropping and intercropping. The prunings were applied at a rate of 6.7 tons/ha in two splits. Measurements were made of soil moisture, fine root biomass, plant height, stem diameter, number of leaves, above ground dry matter yield, leaf area index and maize grain yield. The hedge trees were found to have a considerable amount of fine root biomass in the zone occupied by the maize roots with leucaena being more superficially rooted than calliandra. The maize fine root biomass was higher in alley cropping compared to monocropping. Addition of prunings reduced the maize fine root biomass. Comparing the maize and tree fine root biomass at both depths, the maize plants had more biomass at both depths than the trees. Trenching slightly improved grain yields though this was not significant. Application of prunings improved maize crop yields as compared to the control and fertilizer treatment. Soil moisture competition did not feature in the experiment since there was plenty of rainfall during the growing season. Based on the fine root distribution, calliandra emerged a better alley cropping tree than leucaena in this experiment.
Ecology, epidemiology and pathogenic variability of pseudomonas syringae pv. phaseolicola in the southern highlands of Tanzania.
(Sokoine University of Agriculture, 1998) Gondwe, Betty James
Investigations were carried out to determine races of Pseudomonas syringae pv. phaseolicola existing in the Southern Highlands of Tanzania and the relationship between motility and virulence of the pathogen. The epiphytic survival of a brown diffusible pigment producing strain (9337- uncertain race type) and a non brown diffusible pigment producing strain (9359-racc 6) of P.s.phaseolicola was also studied in bean genotypes Kablanketi and Uyole-90. On the basis of cultural, biochemical and pathogenicity tests, 260 isolates were identified as P.s.phaseolicola. Using the Biolog Microplate identification system, other isolates of fluorescent pseudomonads encountered were confirmed to be Pseudomonas fluorescens A and Pseudomonas syringae pv. syringae A. Race determination, using eight halo blight differential bean cultivars, showed that races 1,2, 3, 4. 5, 6. 7b and 8 exist in the Southern Highlands of Tanzania. In addition, 7.6% of the strains characterized were of uncertain race type, suggesting occurrence of wider pathogenic variability than could be categorized using the current set of halo blight differential cultivars. Races 3 and 6 were the most prevalent. Race 3 occurred at a high frequency in Mbeya and was predominant in Nkasi and Sumbawanga districts. About 32% of the isolates collected produced the brown diffusible pigment in vitro. Some brown pigment producing strains were found to be race 3. Race 3 strains, which cause a very strong hypersensitive reaction associated with systemic necrosis on several bean genotypes including Tendergreen and A53, exist in the region. Strains isolated from N.wighlii and Desmodium sp. and characterized as race 7b were less virulent on bean cultivars A52 and A53 than race 7b strains originating from P. vulgar is.I hirly-six germplasm accessions were tested for resistance to eight strains of P.s.pliasi'olicola. New sources of resistance to races 1. 3, 4, 5, 7b, and strains 9337 (brown diffusible pigment producing strain) and 14494 (closely related to race 9) were identified. Differences in motility between and within races of P.s.phaseolicola were also demonstrated. Results from epiphytic population studies showed that there were differences between bean genotypes Kablanketi and Uyole-90 in supporting the epiphytic populations of die brown diffusible pigment producing strain 9337 and race 6 (strain 9359) of I’.s.p/iiixeolieolii. The resulting halo blight disease severity scores were generally low but comparably higher on Kablanketi inoculated with race 6. In vitro and in vivo studies under greenhouse conditions were conducted to determine the inhibitors effect of garlic bulb extract on growth of races 3, 6 and a brown diffusible pigment producing strain 9337 (uncertain race type) of P.s.phaseolicola. Antibacterial activity was shown as clear zones of inhibition. Halo blight disease incidence and severity on bean genotypes Uyole-90. Canadian Wonder and Kablanketi were significantly reduced. Pseudomonas syringae pv. phaseolicola strains 9337 (a diffusible brown pigment producer of an uncertain race type) and 9359 (race 6) survived in immature flat green pod tissues at 18 to 25°C in the laboratory for nine months.
The effect of soil water deficits on growth and development of selected common bean cultivars (phaseolus vulgaris l.)
(Sokoine University of Agriculture, 1999) Maghembe, Neema Abdallah
Research was conducted to study the performance of three common bean (Phaseohis vulgaris L.) cultivars grown under stressed and non-stressed water conditions. Two experiments were conducted at Sokoine University of Agriculture (SUA) located at 6°.5’ latitude South, 37°.3’ longitude East; and 525m a.s.l The first experiment was conducted under screen-house conditions between March and May, 1998; while the second experiment was conducted under field conditions in May through August, 1998. The experimental design used was a split plot with four replicates. The main treatments were irrigated and non-irrigated. The subtreatments were three common bean cultivars. In the screen-house experiment, ten litre plastic pots filled with sandy clay loam soil were used for planting. Under the field experiment, the size of each subtreatment was 10.8m2 and the crop was spaced at 60 by 20cm. Sulphate of ammonia and triple supper phosphate were applied at 30kg N and 25kg P per hectare, respectively. Data were collected from underground and above ground plant parts at first flowering (Rl), 50% flowering (R4), physiological maturity (R8) and harvest maturity (R9). Highly significant effects of irrigation treatments, cultivars and their interactions were obtained at all sampling times except at R1 when the main treatments had just been applied. Non-irrigated plants completed their life cycle earlier than irrigated plants. Stressed cultivars had severe leaf curling, wilting and drooping between R4 and R8. Non stressed cultivars had significantly higher plants heights, leaf area, root length, total biomass and seed yield than drought-stressed plants. It was also noted that stress levels differ from one cultivar to another. Cultivar SUA 90 gave the highest total biomass and seed yield in both experiments under both maintreatments. This was followed by "Rojo" and finally Canadian Wonder. The BEANGRO crop simulation model indicated that root length, root weight, leaf weight, and specific leaf area were very important parameters to consider when evaluating bean genotypes for drought tolerance.
Integrated management of perennial wild rices in lowland irrigated rice
(Sokoine University of Agriculture, 1999) Mkocha, Magdalene Nelson Enock
Two field experiments were conducted during the season 1997/98 at Kapunga Rice Irrigation Project (KRIP) in Mbeya region to determine the influence of perennial wild rices on rice yields and to evaluate effectiveness of ploughing depths, hand weeding, herbicides and seeding rates in the control of the wild rices and other weeds. Experiment 1 was a split plot in a randomized complete block design with three replications. Ploughing depths (10, 15, 20, and 25 cm) constituted the main plots while the seeding rates (110, 130, 150, 170 kg ha'1) were the subplots. Pregerminated IR 54 paddy seeds were sown on 13 Februaiy 1998. Data collected included wild rice fresh and dry biomass before and after treatments, plant height at booting and at maturity, number of tillers, and panicles per plant and per square metre, number of grains per panicle, percentage ripened grains and grain yield per hectare. Combinations of 15 cm x 170 kg ha'1 (ploughing depth x seeding rates) recorded the highest grain yield of 4852.0 kg ha'1 which was significantly (P
Influence of wood ash as a source of supplemental calcium on groundnut (arachis hypogaea l.) yield and seed quality
(Sokoine University of Agriculture, 1999) Lugaila, Mariam Seif
Groundnut (Arachis hypogaea L.) has a peculiar calcium (Ca) requirement particulary for its development during the initial peg^ng and seed development. For this purpose supplemental Ca is usually recommended when a crop is grown on acid soils with low cation exchange capacity (CEC). To evaluate the influence of supplemental Ca on yield and seed quality of selected groundnut cultivars two field experiments were conducted at Sokoine University of Agriculture in Morogoro region during the months of February ■ May and April - August, 1998. The experiment was laid out as a split - plot in a randomized complete block design with three replications. Three groundnut cultivars Baka, ICGV 86112 and Spancross were the main plots, while calcium levels 0, 60,100,140 kg Ca/ha obtained from wood ash and one treatment of 140 kg Ca/ha from hydrated lime were the sub plots. Each subplot had eight rows, 2 m long with in - row spacing of 10 cm. The results show that there was significant (P < 0.05) cultivar effect on the number of filled pods per plant, seed size, seed yield per plant and seed diameter. Application of Ca had no significant effect on most of the variables analyzed. However, there was significant interaction (P < 0.05) between cultivar and Ca on seed yield per plant. The lack ofresponse to Ca observed in this study suggests that there was no difference in Ca uptake among cultivars used. Significant interaction between cultivar and Ca level on seed yield per plant in experiment 2 suggests that cultivars used respond differently to applied Ca with respect to this character. Soil analysis at the end of each experiment indicated that the applied Ca levels had an increasing effect on soil pH and exchangeable Ca suggesting that wood ash may be used for liming acid soils.

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