Department of Crop Science and Horticulture

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A Review of options for speeding the adoption of climate smart varieties: what works and what does not work: Experiences from Tanzania
(nternational Journal of Environment, Agriculture and Biotechnology, 2022-06-08) Bilaro, Atugonza Luta; Tryphone,George M.
Given the efforts invested on addressing climate change adaptation particularly in agriculture, the adoption of climate smart varieties has not met the expectations. A number of crop varieties developed targeting drought prone areas largely remained un-adopted hence unknown to the majority of farmers or lack traits deemed special for adaptation to climate change in target areas. Variety adoption rate is highly dependent on its adaptation to particular environmental conditions including suitability to tolerate drought, salinity and acidity and ability to meet different livelihood needs such food, fodder and cash. Poor adoption emanates from lack of awareness and the volatility of the farming environment coupled with poor integration of seed business into private public partnership. Rapid adoption of climate smart varieties in Tanzania would require better policy intervention with a well-organized extension system and modifications in variety testing procedures, including the current guidelines for variety release. In this work the authors discuss some approaches that can be used to enhance the adoption of climate smart varieties in Tanzania and cite a few specific cases based on experience from Tanzania.
Adaptation to rainfall variability, socioeconomic factors influencing maize production in crop livestock mixed farming systems in Babati district, Tanzania
(Sokoine University of Agriculture, 2018) Msigwa, Z. P.
Agriculture is an important source of food and economic survival of rural populations in Tanzania however farming activities are highly affected by rainfall variability which cause loss in crops and livestock yield. This study explored adaptation strategies to rainfall variability, socioeconomic factors influencing maize production in mixed farming systems. Specifically, assessed the trends in rainfall and maize production, determined the relationship between trends, identified farmers’ adaptation strategies to rainfall variability and ascertained the influence of socioeconomic factors on maize yields in the mixed farming systems. The study employed questionnaire survey method to collect household data. Focus group discussions, key informant interviews, documentary review were also conducted to complement the information. Descriptive and inferential statistical analyses were employed using MS excel and Statistical Package for Social Sciences (SPSS) programs. Annual rainfall and maize yield data for the past ten years were used to study the trends and trend relationship in rainfall and maize production. Results showed increasing trends in rainfall with high inter annual variability and decreasing trends in maize production. The relationship between rainfall trend and maize production was found to be insignificant (p value = 0.927). On the adaptive capacity of the farming system to produce maize, the mixed farming system found to be efficient in adapting to rainfall variability effects with the average maize yields of 2.57 tonha-1 compared to 1.36 tonha-1 in non-mixed. Household size, farm size, the costs of pesticide, and farmers’ access to credits had a significant influence on maize production in the study area. The study recommends that education on environmental management should be done to reduce vulnerability to inter annual rainfall variability, up scaling of the crop livestock mixed farming system to other areas of Tanzania and formation of farmer managed co-operatives to assist in the provision of soft loans with affordable interest rates for meeting the costs of inputs.
Adapting coffee (Coffea Arabica, L.) production to climate change through types of seedlings and soil fertility management practices in Tanzania
(Sokoine University of Agriculture, 2024-05) Mbwambo, Suzana Gasper
In Tanzania, coffee is the second largest traditional export commodity after tobacco, accounting for 24 % of the country‘s total foreign exchange earnings. Average annual production has stagnated at about 50,000 metric tons over the past 35 years. One of the widely held reasons is climate change, manifested by high rainfall variability and decline as well as increase in temperature. Elsewhere different adaptation strategies like use of shade trees, drought tolerant coffee varieties and organic fertilizer have been proposed to deal with the effect of climate change on coffee production. However, climate change adaptation studies for coffee production in Tanzania are largely missing. An overall objective of this work was to develop agronomic techniques for adapting Coffea arabica, L. production to climate change. Specifically, the study aimed to: 1) asses coffee growers‘ perceptions on climate change; 2) asses the relationship between scientific climate change record and production records; 3) evaluate field performance of compact coffee variety under selected propagation methods and soil fertility amendment practices and 4) determine the role of type of seedling and fertilizer management practices in increasing resilient of coffee species to the changing climate. The study was undertaken in the Northern Highland zone (Kilimanjaro and Arusha regions) and Southern Highland zone (Songwe, Mbeya and Ruvuma regions), purposively selected based on the level of Arabica coffee production. First a survey was conducted to examine smallholder farmers‘ perceptions of climate change. The findings indicate that, 163 (67 %) farmers perceived climate change has been taking place in their areas (increase in temperature and decrease in rainfall); the most influential factors in their perception being level of education, farming experience and access to climatic information. Farmers‘ perceptions were also consistent with meteorological data both pointing to significant decline in rainfall and increase in temperature. Smallholder farmers have been responding to climate change through planting shade trees, use of disease-tolerant varieties, soil fertility management, and irrigation practices. A follow- up study was conducted to assess the impact of current climate change on Tanzania‘s Arabica coffee production. The findings reveal minimum temperature has been increasing at a higher rate than the maximum temperature in both zones. Increase in minimum temperature by 1°C during short rains and annual mean temperature resulted in a significant coffee production decrease in Kilimanjaro and Arusha regions by -6,041 and -4,450 tons respectively. Field experiments were also established to evaluate performance of cutting, grafting and seed propagules when combined with 75 g N. P. K tree-1, 37.5 g N. P. K +10 Kg Farmyard manure (FYM) tree-1 and 37.5 g N. P. K +20 Kg FYM tree-1. Two split plot experiments laid out in a Randomized Complete Block Design with three replications were established at the two locations (Lyamungu-Hai district and Burka - Arusha district) based on the existing climatic gradient; cutting- propagated plants resulted into highest yield ranging between 1800- 3600 Kg green coffee ha-1 while grafted-propagated plants had the lowest green coffee yield (600-1700 Kg ha-1.). The fourth study utilized climatic data from Coordinated Regional Climate Downscaling Experiment under Representative Concentration Pathway 4.5 to evaluate the potential of cutting, seed and grafted seedlings in attenuating the effects of climatic conditions using Dynamic Agroforestry Coffee model. During the Near-term period (2026-2056) rainfall will increase in Kilimanjaro region at the range of 0.2-13 % while in Arusha region the increase will be 6.05-13 %. Minimum temperature is expected to increase at higher rate than maximum temperature at the range of 1.4-1.48 °C in Kilimanjaro region and in Arusha region at the range of 1.36-1.64 oC. The use of cutting, seed and grafted propagated coffee plants when combined with FYM will result into 40% 35 % and 10% yield reduction respectively. Specific Leaf Area (SLA) among the three types of seedlings also varied; 28 (cutting), 19 (Seed) and 9 (grafted). Higher SLA observed in cutting-propagated plants may affect coffee production since it is linked to high loss of water in plants. Future higher yield loss was observed with the use of inorganic fertilizer (38%) than FYM (18%) in all the three types of seedlings. Based on the above results, it can be concluded that during the last 40 years, coffee farmers from the Northern and Southern Highlands zone of Tanzania have experienced increase in temperature and decrease in rainfall. Rise in minimum temperature and decline in long rains has significantly affected coffee production in the Northern Highlands zone. Similar to the historical period, minimum temperature is expected to increase at the higher rate than maximum temperature in the Northern Highlands zone during the Near-term period. Integrated nutrients sources are able to provide sufficient nutrients to the three types of seedlings as the recommended rates of inorganic fertilizer. Yield of cutting propagated plants under the age of four years if established at the same time with seeds and grafted propagated plants is significantly higher than that of its counterpart. However, grafted propagated plants are more resilient to climate change. It is therefore recommended that, integrated soil fertility management (37.5 g N.P.K +10 Kg FYM) tree-1 to be used as one of the adaptation strategies because apart from providing nutrients to the coffee plants the package also helps in improving water retention properties of the soil. In addition, seedling distribution should be location specific, with cuttings-propagated plants being distributed in areas with rainfall above 1200 mm year-1. The findings hold significant policy implications for enhancing coffee production in regions affected by climate change. Policymakers should enhance timely and accurate weather information delivery along with developing institutions responsible for education and extension services provision. Multiplication and adoption of improved coffee varieties has to be enhanced and promoted by the policymaker. By promoting adoption of improved coffee varieties policymakers can enhance farmers' adaptive capacity and reduce the vulnerability of coffee production to climate-related risks. Future studies will focus on monitoring the response of three types of seedlings above the age of four years assuming that at a later age coffee tree will have reached its maximum production and so more nutrients and water will be required.
Agronomic package for maize production in semi-coral environment of Pemba, Zanzibar
(AJOL, 2017) Msuya, D. G.; Ali, O. M.
Maize is an important food crop in the semi-coral area of Pemba Island. Production has however never met demand due to very poor yields, about 1.0 t/ha in the area. An experiment was conducted to establish agronomic recommendations for increasing the maize crop productivity. Three improved varieties (Staha, Situka, TMV-1) were tested against variety JKU, a locally grown type in the area. Treatments included four nitrogen rates (23, 46, 70 and 90 kgN/ha) and three plant densities (44,444; 53,333 and 66,666 plants/ha). The treatment sources of variation (varieties, densities and fertilizer rates) had significant effects on growth and yield of the maize crop. Use of variety Staha significantly (P < 0.05) improved yield compared to the local variety (JKU) and the other tested varieties. Yield difference between best performing and least performing variety was about 69%. Through optimized spacing yield difference as much as 32.9% was achieved while through improved Nitrogen fertility yield was increased by as much as 28.8%. The use of variety Staha, grown at a spacing of 75 cm × 20 cm giving a plant population of 66,666 ha-1; and the use of nitrogen at 70 kgN/ha is recommended for best maize yields in the area. The best practice is to optimize all the three factors in combination.
The alarming spread of banana Xanthomonas wilt in eastern Democratic Republic of Congo and its impact on food security and income
(Global Science Books, Ltd, 2010) Dowiya, N. B.; Blomme, G.; Dheda, D. B.; Rweyemamu, C.; Velly, D.; Vigheri, N; Milambo, A.; Eden-Green, S.; Karamura, E.; Maerere, A.
Xanthomonas wilt of banana (caused by Xanthomonas campestris pv. musacearum) is an unforgiving disease. Rather than merely reducing yield, as do many diseases, it causes the fruit to ripen prematurely and rot. Since 2001, the disease has spread to several countries in east and central Africa. It was first observed in the territory of Masisi, 72 km northwest from Goma in North Kivu Province, DR-Congo in 2001. During a survey conducted in May 2006 in the framework of the USAID-funded Crop Crisis Control Project (C3P), Xanthomonas wilt was also observed in the Mahagi and Irumu territories, Oriental province (north-eastern DR-Congo close to the border with Uganda) and in the region between Beni (north Kivu, DR-Congo) and Bundibugyo (western Uganda). Here the disease had most likely spread from infected areas across the border in Uganda. It had also spread over an area with a 50 km radius in Kitchanga, Masisi, North Kivu. A survey conducted in May 2008 in the framework of the Belgian-funded project CIALCA, reported that Xanthomonas wilt had entered South Kivu (Minova, Kalehe territory). In north Kivu the disease is currently present in the districts of Masisi, Rutshuru, Beni, Nyiragongo and Walikale and in Oriental province the disease is currently present in the Mahagi and Irumu districts. The disease has thus spread over an area more than 600 km long (north-south axis). At least two million people in eastern DR-Congo are impacted by this disease which threatens food security and farm income. The most important means of dissemination are infected planting materials, contaminated farm tools and insect vector transmission. Extension efforts to contain the spread of Xanthomonas wilt are hampered by insecurity and inaccessibility of large parts of eastern DR-Congo.
Altered response to biotic and abiotic stress in tissue culture-induced off-type plants of East African Highland Banana (Musa AAA East Africa)
(Asian Network for Scientific Information, 2008) Msogoya, T. J.; Grout, B. W.
This study was conducted to investigate black sigatoka disease and drought stress responses of off• type plants derived from shoot-tip micropropagation of East African highland banana (Musa AAA East Africa) landrace Uganda. Results showed that the off-type plants were more (p<0.05) tolerant to black sigatoka disease with the infection index of 17 .5% compared to 30.1 and 22.8% of the micropropagation (Ml') derived phenotypically normal plants and Conventional Propagation (CP) derived plants with no tissue culture history in their ancestry, respectively. On the contrary, the off-type plants were more (p<0.05) vulnerable to water stress with leaf senescence of 87.7% at soil water deficit of 630 millibars. The leaf senescence of the 1v1.P and CP derived plants at the same soil moisture deficit was 79.5 and 66.7%, respectively. During this stress period each off-type plant produced one sucker, while the true-to-type plants were unable to do so. Leaf structural analysis revealed that the off-type plants had higher (p<0.05) stomatal density of 16.0 mm-2 of the upper leaf surface. Conversely, the MP and CP derived plants had each 12.3 and 11.0 stomata mm ? of the leaf upper surface. Similarly, the off-type plant leaves were more hydrophobic with higher (p<0.05) epicuticular waxiness of 684.6 μg cm ". The epicuticular wax content of the 1v1.P and CP derived plant leaves was as low as 646.2 and 647.7 μg cm ", respectively. The water stressed off-type plant leaves exhibited higher (p<0.05) membrane damage with ion leakage of 168.2 μS cm" compared to 139.7 and 136.8 μS cm" of the 1v1.P and CP derived plants. Moreover, the water stressed leaves of the off-type plants had enhanced total antioxidant activity of 5.17 M trolox equivalent per milligram proteins, whereas the total antioxidant activity of the MP and CP derived plant leaves was as low as 3. 76 and 3.67 M trolox equivalent per milligram proteins, respectively.
AMMI analysis for stability and genotype by environment interaction on common bean (Phaseolus vulgaris L.) genotypes in Mbeya region, Tanzania
(Current Journal of Applied Science and Technology, 2022-08-13) Muhamba, George Tryphone; Bilaro, Atugonza Luta
A significant Genotype by Environment Interaction (GEI) makes selection of stable genotypes difficult. This study was conducted to establish the effect of GEI on yield of Common bean genotypes and reduce complaints on the under performances. Eighteen (18) Common bean genotypes were assessed for variation in gene expression linked to yield and yield predictors on three different districts in Mbeya region (Mbarali, Mbozi and Mbeya districts). Regression, pooled ANOVA and AMMI biplot models were used to evaluate the data. Variety performance showed significant variations in yield between the districts. A similar scenario was observed in regard to yield predictors. Regression analysis showed that in Mbarali 50% was the significant yield predictor (P = 0.027) while pods/ plant was the trait mostly linked to yield in Mbozi. (GEI) analysis using the AMMI model revealed that best variety performance by location based on yield. Interaction principle component (IPC1) was highly significant (P = 0.0001) and contributed about 69.1% of GEI variation. The genotypes SER 83 and RCB 266 where highly adaptable in Mbarali site. The genotypes SER 45 and KG 521 showed specific interaction with the environment of Mbozi district. A total of five genotypes proved to be superior in Mbeya district. The most adapted stable variety with highest grand mean yield across all three mega environments was RCB233 (IPC1= 0.07, yield = 1073 t/ha). The environment in Mbarali was found to be most predictable for evaluation of Common bean genotypes.
Aspects of biology and ecology of citrus leafminers (lepidoptera: gracilariidae) in major citrus growing regions of Tanzania
(Sokoine University of Agriculture, 2015) Nguvu, Giovanni
Field investigations on the occurrence, incidence and damage severity of the Citrus Leafminer Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) on Citrus crops were conducted in Morogoro Rural, Muheza and Kinondoni districts from December 2011 to September 2012. Fifty citrus fields were randomly selected in each of Morogoro Rural and Muheza districts from which 10 000 trees (>5 years old) were examined for leafminer damage signs. A total of 25 seedling nurseries (plants <5 years) were assessed in Kinondoni district. Occurrence of the pest was noted in almost all fields albeit at low incidence (2%). Kruskal Wallis analysis of the incidence data showed neither spatial nor temporal variations between the locations and time of survey. Damage severity in Kinondoni showed an increasing trend from December 2011 to June 2012. Based on the observable morphological features of the collected specimen and damage signs, the pest was suggested to belong to the genus Phyllocnistis and the species citrella. Total development time was longer at 20 0 C and shorter at 30 0 C with 28 days and 10 days respectively. Oviposition period decreased with increase in temperature, from 9.26 days at 20 0 C to 6.21 days at 30 0 C. Female insects lived longer than males across all tested temperatures.
Aspects of ecology of weaver ants (Oecophylla longinoda Latreille) (hymenoptera: Formicidae) in Tanzania
(Sokoine University of Agriculture, 2016) Nene, W. A.
Studies were undertaken between 2012 and 2015 in Mtwara region, Tanzania to establish an understanding of the factors affecting population dynamics in Oecophylla longinoda. Experiments included assessment on; how viable offsprings are produced, when nuptial flights occur and environmental cues that trigger flights. Oecophylla longinoda queens were collected at four steps: before flight, immediately after leaving the nest, up to 12 h after leaving the nest and after settling naturally following the nuptial flights. Only eggs produced by queens (n=65) collected after settling naturally hatched into larvae. None of the 527 winged queens that were collected before flights and immediately after leaving the nests produced viable eggs. Observations on 56 flights recorded from 25 colonies revealed that, flights took place in the evenings. Days with flights were associated with higher relative humidity (p=0.018), less sun shine (p=0.045) and lower wind speed (p=0.034) when compared to days without flights. This knowledge offers a tool to improve forecasts of O. longinoda flights, facilitating collection of mated queens to stock ant nurseries that would supply ant colonies for IPM-programs. Furthermore, feeds that can be used as food supplements to the ants during food scarcity namely anchovy, earthworm, fish intestines and chicken intestines were tested on 20 colonies. O. longinoda preferred anchovy to the rest of the provided feeds. More ants’ activity was observed on fresh-ground anchovy compared to the dry form. Large sized particles were easily removed than smaller particles. Analytical Hierarchy Process showed that, earthworm and fish intestines were the most available feeds. Thus, during reduced food availability, farmers in the study area can use such materials as feed supplement for O. longinoda colonies. Fresh or dry anchovy of large particle sizes can be used wherever available. On factors affecting temporal abundance of weaver ants, the percentage of shoots with weaver ants was significantly (p=0.0003) associated with cashew growth phases. More weaver ants were recorded during cashew vegetative and reproductive phases than dormancy. Rainfall and temperature negatively affected number of nests, while relative humidity was negatively related to the number of shoots with weaver ants. Thus, weaver ant augmentations strategies should consider the phenology of cashew crop and weather parameters.
Assessing intensification options of common bean cultivation to improve food security on smallholder farms in the northern highlands of Tanzania
(Nelson Mandela African Institution of science and Technology, 2021) Nassary, Eliakira Kisetu
Complementarities of common bean (Phaseolus vulgaris L.) with non-legume food crops and their significances to the agricultural systems are underexploited. Based on the description of this study, eight options were assessed for the sustainable intensification of common bean cultivation (through manipulations of intercropping and rotation) against the monocultures of maize (Zea mays L.), and the improved and local varieties of common bean in the northern highlands of Tanzania. The factors assessed were the cropping seasons/years (S) (2015 to 2017), agro-ecological zones (A) above sea level (lower 843 m, middle 1051 m, upper 1743 m), cropping systems (C) (sole, intercrop, rotation), and bean varieties (V) (improved Lyamungu 90 and local Mkanamna) and their interactions. Results indicated that S, A, C, and SXA, S*C, SXAXC were significant and bean grain yields increased in intercrops ranging from 1.5 to 2.9 t ha'1 with land equivalent ratio (LER) of 1.58. Intercropping over five cropping seasons indicated that with SXV grain yields increased from 0.2 to 3.5 t ha'1 in bean and from 2.3 to 2.6 t ha’1 in maize with LERs of 1.48 and 1.55. In rotations, higher bean grain yields were attributed to S (3.3 t ha'1), C (3.4 t ha'1), and V (2.7 t ha'1) and for maize were in C (2.9 t ha1) and S (2.6 t ha'1). In conclusion, out of eight assessed options, this study found two main useful options for improving food security on smallholder farms in the northern highlands of Tanzania. The options were continuous cultivation of the improved and/or local varieties of common bean in intercrops with the maize throughout two rainy seasons of the year (long and short). Another option was cultivation of the improved and/or local varieties of common bean intercropped with maize in the long rainy season and rotating of these intercrops with the maize cultivated in the short rainy seasons. Importantly, the improved bean variety Lyamungu 90 was heavier in weight, using the same number of seeds, than the local bean variety Mkanamna, which provided additional factors to be considered to improve income where weight is the acceptable standard in the market.
Assessing the efficiency of soybean [glycine max (L.) merrill] genotypes in phosphorus uptake and nitrogen fixation
(Sokoine University of Agriculture, 2015) Mshamu, Abubakari
An experiment was conducted at Ilonga Agricultural Research Institute during the 2013 cropping season in order to assess the efficiency of soybean genotypes in phosphorus uptake and nitrogen fixation. The study was conducted between March 2013 and July 2013. The experiment was designed as 4 x 7 factorial experiments in randomized complete block and laid out in split-plots arrangement with three replications. The main plots were four P fertilizer levels (0, 15, 30 and 45 kg P ha -1 ), while seven soybean genotypes (TGX 1895-33F, TGX 1895-4F, TGX 1954-1F, TGX 1871-12E, TGX 1844-4E, TGX 1440-1E and Bossier) constituted the sub- plots. The N fertilizer at a rate of 10 kg N ha -1 was applied in all experimental plots as a starter dose. Plant height, days to 50% flowering, P and N uptake, number of nodules, number of active nodules and reduced ethylene were measured at full flowering. Number of pods per plant, seeds per pod, 100 seeds weight and grain yield were obtained at harvest. Results showed that TGX 1895-33F and TGX 1954-1F were identified as high P uptake genotypes with 0.4064 and 0.3831 mg P/plant, respectively. Also they were identified as efficient in N 2 fixation with the highest amounts of reduced acetylene from detached nodules with 7.14 and 6.96 μ mol C 2 H 4 h -1 g -1 , respectively. The high yielding genotypes were identified to be TGX 1954-1F, TGX 1844-4E and TGX 1440-1E (P ≤ 0.05) which had grain yield of 1706, 1892 and 1863 kg ha -1 , respectively. Based on the results from this study, it is recommended that genotypes TGX 1895-33F, TGX 1954-1F and TGX 1844-4E be used in the breeding programmes at the Institute.
Assessment and management of post harvest losses of fresh mango under small-scale business in Morogoro, Tanzania
(JAPS, 2011) Msogoya, T. J.; Kimaro, E. S.
This study was conducted to assess postharvest losses and the effect of shade during wholesale market and hot water treatments on storage of mango cv. ‘Dodo’. To assess postharvest losses, mature fruits were packed on semi-rigid bamboo cartons, loaded on a truck without separators in between cartons and transported from Mkuyuni ward to Morogoro urban, Tanzania. The effect of heat stress during the wholesale market was evaluated by storing mango fruits under the sun, woven polypropylene shade and black net shade at Sokoine University of Agriculture. Mango fruits dipped in hot water at 60° C for 10 minutes were compared with untreated ones as control. Results showed that the fruit total postharvest losses were 43.8 % with the wholesale market, transport and harvest stages accounting for 30.6 %, 10.6 and 2.6 % of the total losses, respectively. The main features of fruit deterioration during the wholesale market stage were softening and microbial decay each accounting for 50.7 and 39.6 % of the total losses within the stage, respectively. Microbial decays of 7.2 % and mechanical injuries of 2.0 % were the major features of mango fruit deterioration during the transport and harvest stages. Storing fruits for three days under the woven polypropylene and black net shades significantly reduced fruit postharvest losses by 52.7 and 38 %, respectively in comparison with fruit storage under the sun. Hot water treatment reduced the incidence of microbial decay by 85 % and improved fruit total soluble solids content by 15 % in comparison to untreated fruits. However, hot water treatment reduced fruit firmness and shelflife by 56.0 and 71.4 %, respectively. In the short term, wholesale traders are advised to store fruits under the polypropylene shade while in the long term, municipal and council authorities are argued to construct cold storage facilities for fresh fruits. Furthermore, farmers are advised to disinfect mangoes with hot water, especially those purported for immediate marketing.
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.
Assessment of physical quality and health of farmer saved pigeon pea (Cajanus Cajan) seeds in Babati and Karatu districts
(Sokoine University of Agriculture, 2018) Theophili, T.
An assessment of quality parameters of farmer saved pigeon pea seeds was conducted in Babati and Karatu Districts in northern Tanzania. Pigeon pea seed samples were collected from 80 households (farmers), 40 from each district; for testing of their physical and health quality status with respect to three post-harvest handling practices (storage, pre storage seed treatment and seed sorting) following ISTA procedures. Results were then compared with national standards of pigeon peas seeds in Tanzania. Very few of the samples (15% in Babati and 12.5% in Karatu Districts) met the minimum quality standards for pigeon peas seed purity which is 97%. About 60 % of the samples from Babati and 55% from Karatu Districts met the minimum standards of moisture content (which is 10%). Similarly, 97.5 % of the samples from Babati and 82.5% from Karatu Districts met the minimum standard for germination capacity which is 70%. Fusarium udum which is a pathogen of seed health significance in pigeon peas was detected in 33 samples from Babati (equivalent to 82.5%) and 36 samples from Karatu Districts (equivalent to 90% of the samples). Eleven other seed infesting fungi were also observed, with Rhizopus spp appearing in all samples and having the highest incidence of 23.2% for Karatu and 16.1% for Babati District. Significant correlation existed between seed purity and incidence of Cladosporium spp and between seed moisture content and incidence of Fusarium moniliforme; but the correlation with purity was positive against expectation. Further study is suggested of scenarios of farmers′ seeds and quality.
Assessment of post-harvest losses of mango (mangifera indica l.) in Morogoro region.
(Sokoine University of Agriculture, 2011) KIMARO, E. S
High postharvest loss of up to 60 % due to improper postharvest handling practices during the supply chain has been reported in fresh mango fruits in Tanzania The study was conducted to determine mango fruit damages in different stages of the supply chain and develops suitable practices for reduction of postharvest losses during the wholesale market in Morogoro region. Based on farmers/traders practices, postharvest losses of mango fruits at harvesting, transportation and wholesale storage were evaluated. Moreover, an assessment was conducted to compare fruit postharvest losses when ‘tenga’ were loaded with or without separators in between for truck transportation and when fruit ‘tenga’ were stored under the sun, woven polypropylene and black net shades during the wholesale storage. Survey data were analysed using SPSS program based on cross tap method whereas data analysis to compare effect of separators between cartons on fruit losses based on Student t-test (P < 0.05). Data to compare effect of shades on fruit losses were subjected to analysis of variance and treatments mean separation was carried out based on Tukey test (P< 0.05). The total postharvest losses of mango *fruits encountered in all stages along the supply chain was 43.8 % with the main damage features being caused by fruit fly maggots, microbial decay and fruit softening each accounting for 8.65, 11.85 and 20.05 % of the total losses, respectively. Conversely, fruit storage under the shades significantly (P < 0.05) reduced fruit postharvest losses from 31.09% under the sun to 9.31 and 11.34 % under the woven polypropylene and black screen shades, respectively. It is recommended that traders should use separators between ‘tenga’ during long distance mango fruit transportation and store fresh mango fruits under polypropylene shade during the wholesale storage market in order to reduce postharvest losses. Municipal or district authorities are argued to construct cold storage facilities for storing fresh fruits.Furthermore, farmers should disinfect fruits against fruit fly eggs and decay micro organism as a strategy to reduce postharvest losses.
Assessment of root knot nematodes (meloidogyne spp.) preferences to commonly grown tomato varieties in Mvomero district
(Sokoine University of Agriculture, 2022) Ombaeli, Samweli
Root-knot nematodes (RKN) are among serious biotic constraints to tomato growers in Tanzania but relatively overlooked. This necessitated to conduct a survey to capture pre- existing knowledge of growers on RKN in Mvomero Disrict, Morogoro, Tanzania. Multistage sampling procedure was used to obtain respondents for interiew. Semi- structured questionnaires were used to collect data from 100 randomly selected respondents in Mlali (33), Doma (33) and Dakawa (34). Data were collected on socio- economic status, awareness of respondents on RKN, tomato varieties grown, seed sources and yield. Results indicate that there was a significant variation (p = 0.01) in awareness on RKN across categories of respondents. However, 59% of respondents were not aware of RKN. There was a significant correlation between farming experience and yield of tomato (p < 0.001), Farming experience and awareness of RKN (p < 0.001) and between yield and knowledge on RKN resistant tomato varieties (p < 0.008). Popular tomato varieties grown by farmers were Rio Grande (14%), Cal J (18%), Roma (10%) and Tanya (16%) while hybrids were Imara F1 (19%), Assila F1 (15%), Jarrah F1 (2%), Zara F1 (3%), Kipato F1 (2%) and Anna F1 (2%). Seventy five root and 75 soil samples of tomato plants at flowering/fruiting stage showing stunting, chlorosis and wilting signs were collected from fields located at least 1km apart in Mlali, Doma and Dakawa. Samples were collected about 25 cm deep using a shovel, packed in sterile plastic bags, labelled and transported to TARI Kibaha Nematology laboratory for RKN analysis. Results revealed the significant prevalence (p = 0.002) and incidence (p < 0.001) of RKN. Despite the occurrence and damage caused by RKN in tomato in the study areas, only one percent of respondents recognised RKN as a serious problem. Awareness campaign on RKN will facilitate farmers’ consciousness of their existence and management.
Assessment of selected agrochemicals in wastewater from horticultural farms in Arusha and their removal by constructed wetlands
(The Nelson Mandela African Institution of Science and Technology, 2014) Lerna, Emmy Solomon
Commercial horticulture has been growing rapidly and has a significant contribution to food security and economic growth in Tanzania. The growth of horticulture industry has been associated with an increase in consumption of agrochemicals on farms. 1 lowever. wastewaters containing agrochemicals are usually discharged from horticulture farms into the environment without proper treatment. Apparently, the effects of these agrochemicals on the environment are very complex, and therefore, their undesirable transformations can contaminate water, soil, sediments and biota and consequently cause adverse effects on human health and the environment. This study was aimed at investigating the levels of agrochemicals in wastewater discharged from selected horticultural farms in Arusha and their removal by constructed wetlands. The study reviewed literature on the use of agrochemicals in Tanzania and analysed wastewater discharged from horticulture farms for nutrients and pesticide levels. The literature review on agrochemical use showed that inorganic fertilizers, insecticides, fungicides and herbicides arc mostly used in horticultural fields. The analysis of wastewater from live horticulture farms detected NOj'. PO/\ BOD5 and permethrin in the wastewater discharged into the environment at concentration levels above the Tanzanian allowable limits for discharge. The mean concentration levels ranged from (4.5 - 64) ppm for NO.f, (3 - 48) ppm for POq3’. (57-119) ppm for BOD5 and (0.4 - 0.8) ppm for permethrin insecticide. This study investigated the influence of macrophyte type towards removal of Cu, Fe, Mn. Zn. Endosulfan, L-Cyhalothrin and Permethrin by using bucket experiments and influence of flow rate towards removal of Cu. Zn and Mn in horizontal subsurface flow constructed wetlands (HSSFCWs). The results from the bucket experiments showed a significant positive effect of macrophytes on the removal of Cu, Fe, Mn and Zn. In the HSSFCWs experiments, the removal of heavy metals was as high as 95 % on the average and was found to be independent of flow rate and the difference was statistically insignificant (P>0.05). It w'as observed that regardless of the mechanisms involved in the removal of heavy metals in the HSSFCWs, the overall removal is not limited to transport processes within the wetlands. The conclusion drawn from this research is that agrochemicals are a problem in the environment and constructed wetlands can be used as treatment options for wastewater before it is discharged into the environment.
Assessment of the effect of pruning systems on plant developmental cycle-yield and quality of selected indeterminate tomato lines
(Acta Hort. 1007, ISHS, 2013) Mbonihankuye, C.; Kusolwa, P.; Msogoya, T. J.
Preliminary evaluations have shown that indeterminate new tomato breeding lines produce high yields of large fruits. Pruning systems have been reported to regulate tomato fruit size and overall yield performance. A study to evaluate the effect of pruning levels (non pruning, single stem, two stems and three stems) on plant developmental cycle, yield, and quality of five indeterminate tomato breeding lines and one commercial cultivar was conducted from November 2009 to March 2010 at the Horticulture Unit of Sokoine University of Agriculture, Morogoro, Tanzania. Results showed that two stem pruned plants gave the highest number of marketable fruits per plant. The highest number of non marketable tomato fruits per hectare was observed in unpruned plants. Tomato lines differed in their performance, with the longest period of harvesting, highest number of flowers flowers, highest percentage of fruit-set, the highest yield, high number of marketable fruits observed in lines P20-(03) and 186-2(06), which is probably a result of their genetic characteristic. It was concluded that, the large fruit size of the new tomato breeding lines can be reduced to meet consumer’s needs without reducing yield by two and three stem pruning in lines P20-03 and S186-2(07).
Assessment of the effects of water stress on seed yield of common bean genotypes
(African Journal of Agricultural Research, 2020) Claude Rubyogo, Jean; Mbiu, Julius Peter; Msolla, Susan Nchimbi; William, Magdalena N.
Drought stress is among the most important abiotic factors that contribute to the significant yield reduction of common bean (Phaseolus vulgaris L.). Due to unreliable and poor distribution of rainfall, drought tolerance has become the important train in common bean in bean growing areas. The objective of this study was to evaluate 16 common bean genotypes for drought tolerance under three moisture regimes and identify genotypes with specific traits that improved tolerance to drought that could be recommended for released and become useful parents in the breeding programs. The experiment was conducted in Maruku, Bukoba under screen- house. Based on the drought stress indices which includes drought tolerance index (DTI), Harvest Index (HI) SMC 162, DAB 602, SSIN 1128, DAB 378, DAB 362 and SMR 101 had performed better than other tested genotypes. Also, the results showed that genotypes DAB 582, SRC 59, DAB 602, SSIN 1240, SMC 24, SMR 101 and DAB 362 were drought tolerant with lower and high value of the DSI and YSI respectively. Therefore, the later genotypes can be used in the future breeding programs as the parent for drought tolerance and also can used as a new varieties by farmers.

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