Theses and Dissertations Collection

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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.
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
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
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.
Cashew management and its effect on soils and intercrops: the case of sulphur dusting in South Eastern Tanzania
(Katholieke Universiteit Leuven, 2001) Ngatunga, Edward L.
This study examines management of cashew groves in South Eastem Tanzania and the effect of adopting sulphur dusting on soils and on cashew and its intercrops. Production of cashew nuts, an important cash crop in South Eastem Tanzania, is constrained by powdery mildew disease caused by Oidium anacardii Noack To get high yields, farmers have to dust the trees with 90 kg of sulphur per hectare After a decade of sulphur use, there is widespread concern about future productivity of the soils because buffering capacity of the soils to withstand prolonged sulphur use is not known. Production of cashew nuts is also low due to planting in marginally suitable areas The other associated problem is the lack of a strategy to address soil acidity arising from sulphur use The main objective of the study is therefore to find approaches that will ensure sustainable production and management of the cashew-intercrop based farming systems in South Eastem Tanzania. To evaluate soil suitability for the cashew nut tree, henceforth called the cashew tree, soil profile features and physico-chemical properties of soils of 16 representative cashew groves on the Makonde plateau and 14 in the Inland plains were studied. Soil properties indicate that on the Makonde plateau soils arc sandy, highly weathered, deep and devoid of mottles, nodules and hardpans. Ferralsols constituted over 60 % of the soil groupings in cashew groves sampled on the plateau Several soil groupings such as Acrisols, Alisols, Phnthosols, Cambisols and Phaeozems were found in the plains where soils are generally clayey and often shallow and less weathered. Through multivariate analysis, the relationship of 19 soil parameters and 20 cashew tree parameters revealed that tree dimensions were larger and had higher yields on deep, strongly weathered soils most common on the Makonde plateaux On shallow, weakly weathered soils found in the Inland plains, trees had smaller dimensions and low yield. The fact that the plant grew favourably on the plateau, regardless of the low chemical fertility, shows that cashew trees are more sensitive to physical than to chemical limitations of the: terrain. Buffering capacity of cashew growing soils was studied by titrating soil samples from different groves with acid and relating changes in pH to soil properties. Buffering capacity was strongly and positively correlated with percent clay and weakly with percent organic carbon of the soils. Buffering capacity of soils on the Makonde plateau was comparable to that of soils in the Inland plains. Due to the low initial pH and low clay content of soils of the Makonde plateau, acidification of these soils is more likely to reach to critical levels. To verify to which extent past sulphur dusting affected the soil of farmers’ cashew groves, the pH of 70 sulphur dusted groves was compared to 70 non-dusted groves. The survey indicated that use of sulphur has lowered the pH of soils on the Makonde plateau, while soils of the Inland plains have not been affected. To predict the effects of sulphur use on annual intercrops of cashew trees, twelve 3-year field experiments in which sulphur was applied on maize, sorghum and cowpeas were conducted at three locations. Sulphur rates varied from 0 to 240 kg ha’1. Results showed that sulphur decreased germination percentage and grain yield of sorghum and maize, beginning from the second year of application of 120 kg ha'1 and above The decrease was most pronounced in soils on the Makonde plateau. Cowpeas were tolerant to sulphur use. Through an incubation experiment set out to evaluate the ability of Mikindani lime (burned coral lime), Minjingu rock phosphate and ash from cashew leaves to neutralise soil acidity, Mikindani lime was found to be the most suitable material. It raised the soil pH from 3.8 to 6.0 at the rate of 0.3 ton ha’1 costing USS 10 for procurement and application in the field. Both Minjingu rock phosphate and ash required large amounts of materials, resulting in a higher cost. This study has shown that the most important soil properties to check when planting cashew trees are soil depth and weathering status. Deliberate effort should be made to reduce quantity of sulphur used on the Makonde plateau, as the risk for adverse effects of acidification is highest here As risk for soil acidification is less pronounced in the Inland plains, sulphur use can be continued, however, periodic monitoring of soil pH is recommended. To lessen the acidifying effect of sulphur, its use can be reduced by applying crop cultural practises, such as pruning and burning of infected twigs and leaves. Organic fungicides can be an alternative to sulphur but they have the disadvantage of being more expensive and more toxic to humans and animals than sulphur. Although burned lime has proven to be effective to raise the pH of the acidified soils, further research is needed to investigate its effect on the yield of cashew trees and cashew intercrops. An integrated approach to address the mildew problem should also involve a long-term strategy to evaluate/breed for disease resistant tree types.
Regulation of gynophore elongation and fructification in the peanut arachis hypogaea L.
(Uniiversity of California, 2001) Mnzava, Nameus Abel
The regulation of peanut gynophore elongation and the fructification process were studied using Spanish bunch variety grown under constant temperature (26.5°C), photoperiod (12 hr) and relative humidity (ca 90%) in a growth chamber. The experimental material consisted of tagged flowers or gynophores continuously made available by replanting. A technique utilizing the floral morphology was devised to study effects of exogenous growth substances applied independently or in combinations on the induction of IM activity (gynophore initiation) in the absence of fertilization and syngamy. Growth substances are able to evoke IM activity thus substituting for the syngamic stimulus. The effect of GA was dose-dependent suggesting that it may be a critical factor in gynophore initiation, however, a mixture of GA, IAA and BA was more effective than individual or combined effects of BA and IAA. Morphactin showed stimulatory effect on IM activity. When applied to fertilized flowers, CEPA and Ag+ ions inhibited IM activity, the latter by postponing hypantha abscission. In the absence of exogenous auxin, gynophores initiated without fertilization failed to show geotropic curvatures denoting the role of auxin in mediating normal geotropism. Growth substance initiated gynophores were incapable of fructification and their limited elongation was suggestive of the necessity of proembryonic secondary stimuli for these processes. Gibberellic acid promoted while other tested growth substances i.e. IAA, BA, CEPA, TIBA, CCC and morphactin inhibited intact gynophore elongation. Ovule removal stagnated elongation partially overcome by GA confirming the role of the proembryos for sustained IM activity. Auxin or BA inhibited GA- promoted intact gynophore elongation depending on gynophore age auxin being more inhibitory on the younger gynophores being least responsive irrespective of concentration. When applied to flowers at anthesis, morphactin transiently inhibited geotropic curvature development but copiously altered gynophore trajectory.94. The size and activity of the IM zone decreases towards the ovule base with progressive gynophore lengthening. Gibberellic acid affects elongation by increasing length of IM cells whose elongation is basipetally polarized. inverse The relationship between fructification depth and gynophore length is attributed the to decreasing size and activity together with internal differentiation of the IM zone with age. A definition of peanut 'fruit-set' is suggested as being at time of IM induction (i.e. gynophore initiation phase of fruit development) and the gynophore as a physiologically unique young fruit. The observation that ovule removal delayed but did not prevent curvature development ot excised gynophores suggested the perceptive and responsive nature of the IM to geotropic stimulus. Morphactin enhanced elongation of excised gynophores for all concentrations with optima at 0.1 and 10 ppm and effectively altered geotropic curvature even at 0.1 to I ppm. Higher morphactin concentrations relationship rendered between gynophores the ageotropic. anti-geotropic effect There and was an inverse growth stimulation. Morphactin, however, failed to stimulate growth in the presence of auxin which partially reversed its effects on geotropism. Auxin inhibited excised gynophore elongation for all concentrations but progressively reduced the degree of curvature. The effect of morphactin and auxin on elongation are further evidence on gynophore physiological similarity to roots and the regulation of geotropic curvature by auxin. Tri-iodobenzoic acid (TIBA) and BA inhibited elongation and curvature with increasing concentration, TIBA more drastically than BA. While GA stimulated growth without appreciable effects on curvature, it partially reversed concentration dependent ancymidol-induced inhibition of these parameters. The fructification process, characterized as simultaneous cessation of gynophore elongation and ovule enlargement is enhanced by growth inhibitors,95. morphactin, IAA and CEPA while GA postponed it by perpetuating IM activity with resultant greater fructification depths. The inhibitory effects of Ag+ions, an anti-ethylene agent on fructification suggest the involvement of ethylene in regulating this process. Depth perception by gynophores is attributed to endogenous hormones acting on the IM. Pericarp growth which is mainly by water retention by the tissue precedes that of the seed but the latter accumulates most of the dry weight in the course of growth. Benzyladenine (BA) enhances fruit growth by increasing water content and kernel dry matter. Distal seed growth was greatly improved by BA treatment by increasing its sink strength which resulted in the reduction of pops and single seededness.
Serological and molecular characterization of begomoviruses infecting cassava (Manihot esculenta Crantz) in Africa
(Sokoine University of Agriculture, 2001) Karakacha, Hassan Were
The outbreak of an extremely severe form of cassava mosaic virus disease (CMD) that is sweeping across East and Central Africa and causing food shortages and consequently famine related deaths provided the incentive for this study. A diagnostic survey of the disease was conducted in cassava growing areas of Kenya, to identify the viruses associated with the disease and to study the presence of whitefly transmitted begomoviruses namely, African cassava mosaic virus(ACMV), East African cassava mosaic virus (EACMV) and the recombinant Uganda variant virus (UgV). This “new" UgV virus was of particular interest, since it was this virus type which was found persistently associated with the severe form of CMD. In addition, cassava samples were obtained from many other cassava growing regions in sub-Sahara Africa, to gain an overview of the identities and distribution of viruses causing CMD in Africa.A total cf 230 leaf samples and 185 hardwood stem cuttings were collected and analyzed. Disease severity data were collected and viruses were typed and characterized using ELISA and PCR. In Kenya, the disease incidence was highest (80-100%) in the western regions neighbouring Uganda and lowest (25-50%) at the coastal region of the country. In Western and Nyanza provinces, 52.2% of the samples tested were infected with UgV, 21.7% with ACMV and 17.4% with mixed infections of ACMV and UgV. All samples from the coast province were infected with EACMV only and no other begomovirus was found in this cassava growing region. However, in about 15% of the cassava samples, filamentous viruses were found, which were not detected in samples from other regions. When cassava samples obtained from other major cassava cultivating regions of Africa were analyzed, ACMV was the only virus found in West Africa, with very few exceptions of EACMV that was detected in samples from Nigeria and Guinea. Outside Kenya, UgV was detected in samples from Uganda and the Democratic Republic of the Congo, D.R.C. This indicates that UgV is rapidly spreading into western regions of the continent thereby endangering the cassava production in West Africa. Symptoms of begomovirus diseases in cassava were indistinguishable, however,the most distinct and outstanding feature of UgV infections was the almost complete reduction of tuber formation and often very severe fol'ar symptoms which were also induced by double infections with both ACMV and UgV. Symptoms in Nif-C'Hana bentham'ana plants infected with an ACMV isolate Corn Kenya, ACMV-KE, could be distinguished from an ACMV isolate from Nigeria, ACMV-NG, by the bright yellow blotches which are typically induced by ACMV-KE on the inoculated leaves. Symptoms induced by EACMV in N. benthamiana were similar to those induced by UgV and considerably milder than those induced by either ACMV-KE or ACMV-NG. Severely affected N. benthamiana plants were mostly doubly infected with ACMV and UgV. The complete nucleotide (nt) sequences of DNA-A (2781 - 2801 nt) and DNA-B (2724 - 2726 nt) genomic components of selected virus types were obtained. The • sequences of DNA-A genomic components shared a high identity with those of either ACMV, EACMV, or UgV already described, implying that DNA-A was highly conserved among the different cassava begomoviruses. The “new", recombinant UgV was verified by the characteristic and almost invariable recombination sequences present in the coat protein genes of all isolates sequenced. This sequence originates from ACMV, while all other DNA-A regions reflect typical sequences of EACMV. Since the recombination comprised only a short segment of the coat protein, the virus was verified as a strain of EACMV and hence named EACMV-UgV, which is used synonymously with UgV. Analysis of the DNA-B sequence of a Kenyan isolate of EACMV-UgV revealed a DNA-B component identical to those of ACMV isolates described. Furthermore, for all virus isolates with characteristic EACMV-UgV-like DNA-A genomic components, only ACMV-like DNA-B genomic components were amplified. Full-length clones of DNA-A and DNA-B genomic components were constructed and attempts were made to introduce homologous(ACMV/ACMV) and heterologous (EACMV/ACMV; EACMV-UgV/ACMV) combinations of DNA-A and DNA-B genomic components into N. benthamiana plants. Inoculation of linearized constructs containing full-length clones or of partial head-to-tail dimers of DNA-A and DNA-B genomic components resulted in the introduction of DNA-A genomic components into the host plant. However, in heterologous combinations, only DNA- A genomic component was detected in inoculated plants which showed weak
The physiological performance of varietal mixtures of the common bean (phaseolus vulgaris, l.) grown under broadcast or conventional planting methods
(Sokoine University of Agriculture, 2002) Mhile, Oscar Mwashiuya
A study was carried out at Mbozi and Morogoro Districts of Tanzania during the 2000/2001 cropping seasons. The main objective was'to determine the relationship between growth characteristics and economic yield of varietal mixtures of common beans grown by broadcast or row planting methods. The experiment was a split plot in randomized complete block design (RCBD) with four replications. Different varieties were used at each location, which formed the main plots. Five varieties at the highland (kabanima. U-94. U-90. kigoma. and mixed variety), and four at the lowland (rojo. SUA 90. kablankeli. and mixed variety) were used. At each location one variety was a mixture of those varieties. The subplots were the planting methods. The results indicate that broadcast planting increased leaf area index (LAI). intercepted photosynthetically active radiation (PAR), crop growth rate (CGR). total dry matter (TDM), plant height, pods plant’1, and seeds pod’1, while row planting increased radiation use efficiency (RUE). TDM partitioning, branches per plant, and 100-seed weight. Among varieties at the highland location, the mixed variety produced the highest TDM. branches per plant, and grain yield m’?. Kigoma (indeterminate) was the tallest and accumulated the greatest PAR. Kabanima (determinate) was the shortest and performed poorly in dry matter (DM) accumulation, development of LAI. cumulative PAR. CGR. and RUE. At the lowland location, the mixed variety was superior in LAL light interception, and pods per plant. The mixed variety was the tallest and SUA-90 the shortest. At the highland location, row planting had higher grain yield than broadcast planting as compared to the lowland location. The differences were attributed to greater TDM and branches per plant at the highland location, and RUE and pods plant’1 at the lowland location. It is concluded that physiologically there was no difference between broadcast and row planting of common beans. Thus, farmers my use either of the methods. Also mixed varieties could be recommended under- subsistence agriculture but could be economically unsuitable where marketing require quality pure varieties for better prices.
Influence of minjingu phosphate rock application on tephrosia vogellie fallow productivity and subsequent maize response on a ferralsol in morogoro,Tanzania
(Sokoine University of Agriculture, 2004) Mkangwa, Chaboba Zaid
The objectives of this study were to quantify the response of /'. vogelii fallow to Minjingu Phosphate Rock (MPR) application at establishment on quantity and quality of biomass produced. P availability, total inorganic-N. maize yields, and pH and Ca changes on an acidic. I’ deficient Ferralsol. The data w'ere collected from pot. incubation and field experiments. The pot studies were used to assess response of T. vogelii seedlings to MPR. P and Ca applications, and that of maize to 7'. vogehi biomass and MPR applications Incubation experiments were used to evaluate the influence of MPR application on decomposition of 7'. vogelii biomass and N release. and the effects of combined application of MPR and T. vogelii biomass on Pi-P. The field experiments were used to evaluate the effects of MPR application at fallow establishment on /' vogelii performance, maize response to fallow' biomass and MPR applications, and to residual MPR and fallow biomass and fresh biomass applications. In soil of pH 5.9. the quantity, quality and Nz-fixing capacity of T vogelii seedlings were significantly improved relative to pH 5.0. Application of MPR improved these parameters at both values of soil reaction. The quality and quantity of 7'. vogelii biomass depended on P application. Combined application of T. vogelii biomass and MPR significantly increased maize DM yield in the pot and field studies, but depressed Pi-P in the incubation study. Decomposition of T. vogelii biomass was significantly increased only in the first 28 days by MPR application and was not effected thereafter. Minjingu PR application at fallow establishment significantly increased the quantity and quality of T. vogelii biomass, total inorganic- N and Pi-P in the fallow's. Subsequent to fallows, application of T. vogelii fallow'Ill biomass or combined with MPR significantly increased total inorganic-N. The Pi-P. earleaf N and P concentrations, soil pH. exchangeable Ca and maize yields were significantly increased by application of MPR at fallow establishment and by combined MPR with fallow biomass It is concluded that application of MPR on a strongly acid P deficient Ferralsol improves the quantity and quality of T. vogelii fallows and subsequent maize yields
Assessment of germination stimulants from non-host leguminous crops for control of striga asiatica (L) kuntze in semi - arid areas of Tanzania.
(Sokoine University of Agriculture, 2005) Mgonja, Fridaii Nnekia Mbazi
Striga axiatica is one of'the most destructive parasitic need species in the Semi Arid Zone of Tanzania. In an effort to come out with an appropriate and sustainable method of controlling the weed species, two laboratory/screen house and one field experiments were conducted to identify leguminous crop species/cultivars that are suitable for use as trap crops in the control of.S’rr/qr? asiatica. Effectiveness of root exudates of 56 cultivars from six leguminous species on germination of .S’, axiatica seeds were assessed in vitro using Petri Dish (PD) technique. A split plot design replicated four times was used The second laboratory- experiment, aimed at eyaluating the effect of seed coat colour and different plant parts of selected leguminous species/cultiyars on stimulating germination of the parasitic yveed seeds was done used A Completely Randomised Design (CRD) with four replications yvas Both experiments were repeated three times In addition, a 2-years field experiment was conducted to eyaluate the efficacy in situ of the species/ cultivars identified in vitro A Completely Randomised Block Design (CRBD) was used and the experiment w as replicated four times. Results indicated that effectiveness of root exudates depends on Strtga seed population, and cultivars within species differed in their capacity to stimulate germmation of .S’ axiatica seeds. Pigeon pea cultivars ICEAP 00020 and ICEAP 00040; groundnut ex-Bukene; cowpeas white black eyed; bambara groundnut cultivars Nyandani spotted cream and Red ex- Makutupora were found to stimulate significantly (P < 0.001) higher germination percentages of 5. axiatica seeds compared to the other tested cultivars within their respective species. hence were selected for further evaluation in field. Seed exudates from black seededii bambara groundnut stimulated 66.8% germination of .S’, asiatica seeds, which was significantly (P < 0 001) higher compared to percent germination induced by the positive control (41 3%) Germination of Striga seeds exposed to exudates from dill'erent plant pans (roots, shoots and seeds) of bambara groundnuts, cowpeas and groundnut ranged from 15% to 63 4%. which was significantly higher compared to percent germination induced b\ the negative control (2 4%). Rotating legume trap crops with sorghum resulted into 38 - 48% reduction of.S'/r/gfl seeds in the soil as well as reduction of Stnga infestation bv 50% compared to continuous sorghum cropping anti weed free fallow - sorghum rotation. Yields of sorghum grow n after legumes ranged between 0.75 - 2 28 tons/ha. while yields from sorghum after weed- free fallow and sorghum continuous cropping were 0.53 tons/ha and 0.61 tons/ha respective!} Except for cowpeas, all other legume - sorghum rotations resulted into significant!} (P < 0 001) higher yields compared with the weed free fallow and continuous sorghum cropping It is concluded that crop rotation with pigeon pea cultivars ICEAP 00020 and ICEAP 00040; groundnut ex-Bukene. and bambara groundnut cultivars Nyandam spotted cream and red ex- Makutupora can serve as elTective trap crops which would reduce .S' asiatica seed bank and infestations. By inference, rotating sorghum with any of these legumes would boost yields, thereby sparing farmers limited resources, which would have otherwise been spent for other expensive Striffa control measures
Assessment of germination stimulants from non-host leguminous crops for control of striga asiatica (L.) Kuntze in semi - arid areas of Tanzania.
(Sokoine University of Agriculture, 2005) Mgonja, Fridah Nnekia Mbazi
Sin^u asiatica is one of the mosl deslructix e parasitic weed species in the Semi And Zone of Tanzania In an efibrt to come out with an appropriate and sustainable method of conlrolling lhe weed species, two 1 aboralor\7screen house and one field experiments were conducted to identify leguminous crop species/cullivars that are suitable for use as trap crops in lhe control of Stnga asiatica. Eflectiveness of root exudates of 56 cultixars from six leguminous species on germination of S. asiatica seeds were assessed in vitro using Pein Dish (PD) technique. A split plot design replicaied four times was used. The second laboratory experiment, aimed at exaluating lhe effect of seed coat colour and different plant pans oT selected leguminous species/cullivars on stimulating germination of the parasitic weed seeds was done used. A Completely Randomised Design (CRD) with four replications was Both experiments were repealed three limes. In addition, a 2-\ears field experiment was conducled to exaiuate lhe efficacy in situ of the species/ cultivars identified in vitro A Completely Randomised Block Design (CRBD) was used and lhe experiment w as replicated four times. Results indicated that effectiveness of root exudates depends on Striga seed population. and cultivars \\ ithin species differed in lheir capacity to stimulate gennination of S. asiatica seeds. Pigeon pea cultivars ICEAP 00020 and ICEAP 00040; groundnut ex-Bukene: cowpeas white black eyed; barnbara groundnut cultivars Nyandani spotted cream and Red ex- Makutupora were round lo stimulate significantly (P < 0 ()01) higher germination percentages of S. usianca seeds compared lo lhe other tested cultivars within their respect!\e species. hence were selected for further evaluation in field. Seed exudates from black seeded bambara groundnut stimulated 66.8% germination of S. asiatica seeds, which was significant!} (P < ()001) higher compared to percent germination induced by the positixe control (41 3%). Genninaiion of Sfn^a seeds exposed lo exudates from dilTerent plant pans (roots, shoots and seeds) of bambara groundnuts, cowpeas and groundnut ranged from 15% lo 63.4%. which was significantly higher compared to percent germination induced by the negative control (2.4%). Rotating legume trap crops with sorghum resulted into 3X - 48% reduction of Stnga seeds in the soil as well as reduction of Sirica inlesiaiion by 50% compared to continuous sorghum cropping and w eed free fallow 一 sorghum rotation. Yields of sorghum grow n after legumes ranged between ().75 — 2 28 tons/ha. while \ ields from sorghum after weed- free fallow and sorghum continuous cropping were 0.53 tons/ha and 0.61 tons/ha respeclixely Except lor cowpeas, all other legume - sorghum rotations resulted into significant^ (P < () 0()1) higher yields compared with the weed free fallow and continuous sorghum cropping It is concluded that crop rotation with pigeon pea cultivars ICEAP ()0020 and ICEAP 00040: groundnut ex-Bukene; and bambara groundnul cultivars Nyandani spoiled cream and red ex- Makutupora can serve as efTectixe trap crops which would reduce S. asiatica seed bank and iniestations. By inference, rotating sorghum with any of these legumes would boost yields, thereby sparing farmers limited resources, which would have otherw ise been spent for other expensixe Stn^a conirol measures.
Non-composted and spent mushroom substrates for production of Agaricus Bisporus
(The Pennsylvania State University, 2006) Mamiro, D. P.
Commercial production of Agaricus bisporus is dependent upon a substrate prepared by composting. Traditional composting is associated with a number of environmental problems such as the emission of offensive odors and waste water run-off during handling. In addition, after the production of a crop of mushrooms, there is the problem of disposal of spent mushroom substrate (SMS). Thus, preparation of a suitable substrate for mushroom production without the generation of offensive odors and the possible re-use of SMS for the production of a second crop of mushrooms are desirable. The goals of this research were to evaluate two substrates for the production of A. bisporus: a) non-composted substrate (NCS) consisting of red oak sawdust (28%), millet (29%), rye (8%), peat (8%), ground alfalfa (4%), ground soybean meal (4%), wheat bran (9%) and CaCO3 (10%) and b) SMS. Treatments included 1) NCS and SMS alone and in combination, 2) spawn carriers, 3) strains, 4) supplements, 5) time of supplementation, and 6) substrate moisture content. The substrates were sterilized in very high porosity filter plastic bags and then spawned and incubated. Mushrooms were harvested for two flushes and yield, biological efficiency (BE) and mushroom size were determined. The highest yield and BE (27.2 kg/m2, 144.3%) were from 1:1 NCS/SMS spawned with casing inoculum (CI) and supplemented with 10% Target® at casing. The largest mushrooms were obtained from NCS spawned with CI and supplemented at spawning with 3,000 mg/kg Micromax® (57.3 g/mushroom). Mushrooms containing the highest solids content (9.9%) were harvested from NCS spawned with CI (60% moisture content). Supplementation of NCS/SMS with Micromax®, a commercial micronutrient, iv had no significant effect on yield and BE. However, the addition of 0.9% Micromax® (d.w.) to NCS significantly increased yield by 72% (from 8.5 kg/m2 to 14.6 kg/m2). This work shows the potential to produce relatively high yields on NCS or on mixtures of NCS/SMS and that a combination of supplements that contain protein, carbohydrate and micronutrients added at spawning or at casing resulted in improved mushroom yields.

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