Theses and Dissertations Collection

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Nitrogen release from decomposed residues of herbaceous legumes and their effect on maize growth and yield in low nitrogen soil
(Sokoine University of Agriculture, 2013) Chilagane, Emmanuel Amos
This study was conducted at Sokoine University of Agriculture (SUA) located at 6°51'5"S and 37°39'26"E at 525 masl at the site with sandy clay soil pH 5.16 with the overall objective of improving maize productivity through the use of leguminous residues as source of nitrogen (N). Specifically the study aimed at determining the mineralization pattern and total amount of N released from decomposition of legume residues; to assess the effects of legume residues on maize growth and yield and to evaluate the effects of legumes biomass applied on maize yield. The treatments used were control (no legume residue and fertilizer application); application of N (Urea); residues in form of velvets bean {Mucuna pruriens L.), dolichos {Lablab purpureus L.) and sunhemp {Crotolaria ochroleuca G.). Maize variety “Staha” was used as a test crop. Experiments conducted were laboratory mineralization experiment, screen house and field experiments. These experiments were conducted between November 2011 and June 2012. Results showed that sunhemp had the highest N content of 2.77% followed by velvet bean and dolichos with 2.49 and 2.42%, respectively. Total amount of N released over 16 incubation weeks differed significantly (P < 0.05) with the range of 151.22 pg kg'1. Leguminous biomass production was 15.13, 12.67 and 11.75 t ha'1 for velvet bean, dolichos and sunhemp, respectively. Maize grain yield ranged from 1.02 for control to 3.96 t ha'1 with Urea application. Sunhemp, velvet bean, and dolichos resulted in 3.69, 3.6 and 3.49 t ha'1, respectively. As the incorporation of leguminous residues resulted into improvement of soil physical characteristics such as texture, bulk density and moisture content, it is recommended for use in mineral low N soils. This application will enhance poor resources farmers to improve maize productivity.
Evaluation of different common bean (phaseolus vulgaris l.) landraces for biological nitrogen fixation traits and yield
(Sokoine University of Agriculture, 2014) Komba, Charles Anselmo
Bean production in Tanzania barely meets half of the domestic demand because of low yield attributed to low fertility, Nitrogen being the most common deficient. While use of rhizobia inoculants can substantially increase bean yields, less than 1% of the farming population is aware of inoculants. The objectives of this study were, to isolate and evaluate indigenous rhizobia population from nine bean landraces, to test their efficacy compared to commercial rhizobia inoculants in relation to nodulation and yield of common beans (Phaseolus vulgaris). Four experiments were conducted during 2011/12 in a screen house at SUA. Two experiment consisted Leonard jar and the other two were pot experiments in which the soil used were either sterilized or unsterilized. The landraces collected were Kasuka Nywele, Msafiri and Manjano from Mbeya, Nyayo, Soya and Kachumbaa from Arusha and Kabungu, Nyamungu and Karanga from Morogoro. Two sets of Leonard jars were arranged in completely randomized block design replicated three times and the other two pot experiments were arranged in split split plot design. Inoculants in pot experiments used were Nitro-SUA, Underwood Biostacked as commercial and Native. Landrace were the main plot, soil sterilization as a sub plot and inoculants as sub sub plot replicated three times. Data were subjected to analysis of variance using GENSTAT soft ware. Significance differences in N2 fixation were observed among all landraces in all experiments, landraces which showed more promise included Nyayo, Nyamungu, Msafiri and Kabungu. Results also indicate that native rhizobia had comparable symbiotic effectiveness to commercial inoculants in unsterilized soils and vice versa in sterilized soils conditions though soil sterilization was not significant. This study recommend further studies to be conducted in field for landraces which were promising to nodulation to explore more of their effectiveness.
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
Transfer of bruchid resistance into farmer’s preferred dry common bean (phaseolus vulgaris l.) varieties in Tanzania
(Sokoine University of Agriculture, 2012) Thaudensia, Herman
This study was undertaken to transfer bruchid resistance against Acanthoscelides oblectus (Say) and Zabrotes subfasciatus (Boh) conditioned by APA locus and ARC2 genes respectively into four Fanners Preferred Varieties (FPVs) , Kablanket (BSUA 59), Njano Uyole (BSUA 29), Soworo (BSUA 73), Carnadian wonder (BSUA 37) collected from major bean producing regions with geographical and ecological representation of Tanzania’s bean growing areas and five APA locus parents (BTICA 132-4-5, BTICA 132 - 4-1, 1CA 43.3/4-7-5, ICA43.9/10-6-3, ICA 43.9/10-7-2) obtained from interspecific hybrids introgression lines expressing a 33kDa seed storage protein and Arcelin 2 donor parent (2R-41B-20-I) obtained from previously developed inbred lines on Rojo background. Selection of the resistant lines were done using gene specific DNA markers and total seed storage proteins. Seed storage proteins (APA and ARC2) of the developed F3 families from this work were analyzed using one dimensional Sodium dodecyl sulphate polyacrylamide gel electrophoresis (1-DSDS-PAGE) and PCR amplification of the DNA fragments corresponding to the targeted marker size. The generated 86 F3 families from crosses between the four FPVs and APA parent lines were analyzed for the presence of 33Kda APA seed storage proteins. Results indicated that 15 families were homozygous for the presence for APA. The expected band of 33kDa was not transferred in Carnadian wonder (BSUA 37). A total of 100 F3 families were developed from FPVs and ARC2 parents. Results showed that four families two from Canardian (BSUA37) and two from Njano uyole were homozygous for presence of ARC 2 seed storage protein . The Chi square values obtained from each cross with APA and ARC2 agreed with Mendelian ratios implying that both genes were dominant and monogenic inherited. The homozygous lines expressing APA and ARC2 will be subjected to bruchid screening and best for inhibition of bruchid development will be needed as parents for further back crossing breeding
Adaptability, correlation and path coefficient analysis among selected variables of sunflower (ilelianthus animus l.) genotypes
(Sokoine University of Agriculture, 2013) Sabula, Leonard Mhoja
Three genotypes of sunflower (PI 364860, K.Fedha and Record) were evaluated at three locations (Seatondale, Inyala and Uyole) and three spacing regimes (75 cm x 45 cm, 75 cm x 30 cm and 75 cm x 15 cm) during the season 2011/12 to estimate the performance of seed yield and its components. The objectives of this study were to evaluate genotype x environmental interactions among the selected variables and to determine the interrelationships and paths of influence among components of yield. Treatments were combined in a split plot arrangement in a randomized complete block design with three replications. Data were collected and analysed using GenStat 14th Edition. The genotype x environment interaction (G x E) was highly significant for all studied variables, suggesting that the performance of the genotypes were inconsistent in different environments. AU the genotypes at Seatondale and Uyole sites yielded higher compared to Inyala site due to low rainfall amount, temperatures and altitudes existed at Inyala may had contributed to the lowest performance. Therefore, Seatondale and Uyole are recommended to be the best for sunflower production. The genotype PI 364860 was identified to be adaptable and stable on seed yield. Correlation coefficient analysis revealed that seed yield had positive and significant association with number of seeds per head, head diameter, seed weight per head and 100 seed weight at both genotypic and phenotypic levels. Path coefficient analysis indicated that number of seeds per head, 100 seed weight, head diameter and seed weight per head had maximum positive direct effect on yield and they interrelated positively through each other. However, number of seeds per head and diameter interacted positively with most variables in their relations with yield which themselves were the major contributors of grain yield.
Genotype x environment interaction of soybean [glycine max (l.) merrill] for grain yield and nutritional quality in the Eastern Zone of Tanzania.
(Sokoine University of Agriculture, 2014) Rashid, Mussa
A study on genotype x environment interaction (GEI) of soybean [Glycine max (L.) Merrill] genotypes was conducted for grain yield, yield related traits, protein and oil contents at three locations during 2013 cropping seasons. The study aimed at determining the magnitude of GEI on soybean genotypes and identify widely and /or specifically adapted genotypes in the Eastern Zone of Tanzania. Six genotypes were evaluated at three locations in a rondomized complete block design in split- plot arrangements. Environment had strong significant (P < 0.001) differences for all evaluated variables except for crude protein and oil content. Similarly genotypes had significant (P < 0.05) differences for all evaluated variables. Oil was not affected by the interaction between genotype and environment. Genotypes TGX 1954-1F and TGX 1908-8F displayed higher yields at Ilonga. TGX 1954-IF at Kibaha and TGX 1908-8F at Mlingano. The best genotypes for seed yield across the environments were TGX 1954-IF and TGX 1908-8F. On the other hand, TGX 1987-29F had the highest protein content while Bossier had highest oil content within and across the environments. High heritability was recorded for pod length, 100-seed weight, initial plants at germination per plot, grain yield and plant height. High heritability coupled with high genetic advance was recorded for seed yield. Combined data over locations indicated that grain yield was positive and highly significant correlated with number of seeds per plant (r= 0.6119 ) and plant height (r= 0.5626 ). Path coefficient analysis indicated that the highest genotypic positive direct effect on grain yield were recorded in number of seeds per plant (0.545) and plant height (0.315). The highest positive and significant indirect genotypic effects on grain yield were recorded on plant height through number of seeds per plant (0.282) followed by number of pods per plant through number seeds per plant (0.271).
Assessment of regeneration potential of selected local banana (musa spp.) cultivars on different substrates
(Sokoine University of Agriculture, 2013) Nzcyimana, Nicolas
Rice husks and saw dusts are traditionally used as initiation media for banana in vivo propagation. However, their physical properties have undesirable effect on shoot multiplication and growth. The objective of this study was to evaluate the effect of alternative growth media on the in vivo multiplication and shoot establishment in secondary nursery of three selected local banana cultivars. This study was carried out from April to October 2011 at the Horticulture Unit of Sokoine University of Agriculture, in Morogoro, Tanzania. It comprised of experiments established in a split plot under randomized complete block design (RCBD). The main factor was banana cultivars (Bukoba, Mtwike, and Mzuzu), while the sub-factor was the growth media (rice husks as a control, cocus peat and mixed medium). The data were subjected to analysis of variance (ANOVA) and mean separation was done based on Student-Newman-Keuls at P < 5% using COSTAT6.4 statistical software. Results showed that rice husks and mixed medium resulted in earlier (P < 0,05) sucker production at 18.88 and 20.26 days, respectively while cocus peat produced suckers within 23.02 days. Mixed medium (forest soil, farmyard manure and rice husks at 4:2:1 on volume basis) also resulted in the highest (P < 0,05) sucker productivity of 4.67 suckers per corm, the biggest sucker with height of 23.64 cm and collar diameter of 1.92 cm, leaf length and width of 24.13 and 13.10 cm, respectively. On the other hand, cv. Mzuzu produced the highest (P < 0,05) number of 5.70 suckers per corm compared with cv. Bukoba and Mtwike with 3.83 and 2.73 suckers per corm, respectively. The findings suggest that plantains have the best responce to in vivo multiplication while mixed medium is most suitable for enhancing shoot productivity and growth.
The insecticidal potential of neorautanenia mitis (a.ritch) against prostephanus truncates (horn) in stored maize
(Sokoine University of Agriculture, 2011) Assey, Zeno Peter
This study was carried out to evaluate the insecticidal potential of Neorautanenia milis to the Larger Grain Borers Prostephanus truncatus (Hom) (Coleoptera: Bostrychidae) and its mammalian toxicity. Laboratory studies were conducted to asses the efficacy and the basic mode of action of N. milis on P. truncatus. Further studies were conducted to asses the toxicity of N. milis on mammals using rats (Mastomys natalensis). The efficacy was assessed at six rates (0, 1, 2, 5, 7 and 10% w/w N. milis in 50g of maize grains) with 5 replications. The repellency was evaluated in the choice bioassay at five rates (1,5, 10, 15 and 20% w/w N. milis in 50g of maize grains) in 5 replications. The contact mode of action was evaluated using Student’s t or t-test. Anti-oviposition was evaluated in non choice bioassay system at six rates (0, 1, 2, 5, 7 and 10% w/w N. milis in 50g of maize grains) in 3 replications. Actelic super dust at a rate of 0.05g in 1kg of maize was also used for comparison. Mammalian toxicity was evaluated by exposing rats to six rates (0, 5, 12.5,25, 50 and 75% w/w N. milis in Broiler mash) in 6 replications. The lethal dose (LD5q) was determined by the graphical method of Miller and Tainter. Split-plot arrangement in a Complete Randomized Design (CRD) was used while Two-way ANOVA was used in the analysis of data. The results showed that N. milis powder and liquid extracts were statistically significant (p<0.05) in reducing the number of damaged grains. Repellency and ant-oviposition are presumed to be the key mode of action of N. mitis. The study indicated that the plant tuber is toxic to rats, therefore care should be exercised during the preparation and handling of the food stuff treated with N. mitis.
Pest status of citrus psyllids in relation to citrus greening disease (Huanglongbing) in major citrus growing areas of Tanzania
(Sokoine University of Agriculture, 2024-05) Ruboha, Joseph Oswald
The citrus industry is a significant contributor to the global economy, with East African countries like Tanzania playing a crucial role. However, the emergence of Asian citrus greening disease, facilitated by insect vectors such as Diaphorina citri and Trioza erytreae, poses a substantial threat to this sector. This study aims to document the impact of citrus greening and psyllid infestations on Tanzania‘s citrus industry, which results in diminished fruit yield, compromised quality, and economic losses. Field surveys were conducted in major citrus-growing regions in Tanzania, including Ruvuma, Arusha, Morogoro, and Tanga. Data was collected using molecular detection techniques, and the prevalence and severity of Huanglongbing, distribution and abundance of Diaphorina citri and Trioza erytreae were recorded. These factors were then correlated with altitude, temperature variations, and citrus varieties. DNA samples were extracted and analysed using polymerase chain reaction (PCR) to confirm the presence of Huanglongbing in selected samples. The study found regional variations in the distribution and abundance of Diaphorina citri and Trioza erytreae. Altitude significantly influenced psyllid species abundance, with Diaphorina citri decreasing and Trioza erytreae increasing with altitude. The temperature had a weak positive correlation with Diaphorina citri abundance and a moderately negative correlation with Trioza erytreae abundance. Different citrus varieties significantly affected Diaphorina citri abundance, with the ―Late Valencia (Kitenesi)‖ variety having the highest average Diaphorina citri counts per tree. The study also found a negative correlation between altitude and the Disease Severity Index (DSI), suggesting that as altitude increases, the DSI decreases. However, a weak positive correlation was observed between the number of citrus trees in an orchard or backyard and the DSI. Significant variations in Huanglongbing prevalence were observed at both the regional and ward levels. The study concluded that the Mediterranean variety was particularly susceptible to Huanglongbing, while the Valencia, Local variety, Washington navel, and Bitijuma varieties exhibited more resistance. The study also confirmed the presence of Ca. L. asiaticus in symptomatic leaves and the absence of bacteria in asymptomatic leaves using PCR Analysis for pathogen detection. The findings of this study have significant implications for developing region-specific management strategies to protect Tanzania‘s citrus industry, which is vital for food security and rural livelihoods. It is recommended to combine molecular and visual methods to enhance our understanding of the dynamics of Tanzania‘s two crucial citrus psyllid species, Diaphorina citri and Trioza erytreae, reflecting the complex ecological interactions involved. This will aid in the development of effective strategies to mitigate the impact of citrus greening disease.
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.
Harvest stage and postharvest handling approaches to enhance quality of pepper (Piper nigrum L.) in Morogoro district
(Sokoine University of Agriculture, Morogoro, Tanzania, 2023-11) Christian Anitha Katushabe
Pepper (Piper nigrum L.) is an important spice crop whose quality can be affected by harvesting and post- harvesting practices. About 50% postharvest loss of black pepper has been reported in Morogoro district. In order to solve the black pepper quality and postharvest losses, smallholder farmers' harvesting and post harvesting practices were assessed for their effect on quality losses. Specifically, this study aimed to (i) generate baseline socio-economic information on harvest and postharvest handling practices of pepper among smallholder farmers in Morogoro District and (ii) assess the effect of pepper harvesting stages on postharvest quality of three black pepper cultivars commonly grown in Morogoro District. econd study characterized fruit growth and development behaviours of black pepper cultivars grown in Morogoro district. A 4x7 factorial experiment arranged in a Randomized Complete Block Design (RCBD) was used. The third study was carried out to determine the effect of harvesting stages on post-harvest quality of three pepper cultivars grown in the Morogoro district. A 3 x 2 factorial experiment with three replicates arranged in a complete randomized design (CRD) was deployed. Qualitative and Quantitative data collected from five wards of Mkuyuni and Matombo divisions economic information on harvest and post-harvest Ten villages were involved in the study to generate the socio- practices used by farmers. The data were collected using a semi-structured questionnaire, Key Informants (KI), and Focus Group Discussions (FGD). The s iii during the experiments were subjected to Statistical Package for Social Sciences and ANOVA, respectively followed by mean separation for the later based on Turkey's HSD test. The results showed that the majority (86.6%) of the farmers in the study area harvested pepper when at least one berry on a spike turned red. Also, most pepper drying was done in the sun using local mats (86.2%), and stored in polypropylene bags (98.6%). Mould growth was reported as the leading cause of storage postharvest losses (95.75%). Results on fruit growth and development showed that the pepper cultivars grown in Morogoro take 8 to 9 months to reach maturity defined by the presence of at least one ripe berry per inflorescence. The number of well-developed berries per spike and spike length differed significantly (p<0.001) between cultivars. 'Ismailia' had many berries (36.11/spike), followed by 'Babu kubwa' (27.3/spike), 'Babu ndogo' (26.88/spike), and 'Babu kati' (22.25/spike). 'Babu kubwa' had the longest (9.10 cm) spikes followed by 'Babu kati' (7.63 cm), 'Ismailia (6.47 cm), and 'Babu ndogo' (5.36 cm). Berry size and firmness differed significantly (p< 0.001) across cultivars and growth periods. Ismailia had the largest (0.566 cm) and firmest (6.973 kg/mm2) berries compared to other cultivars at mature stage. Berry colour changed significantly (p< 0.001) with stages of development, where berry colour of all cultivars changed from green when young to yellow on the 9th month. These findings can guide farmers in determining the best time to harvest each cultivar. iv Results also indicated significant interactions between harvest stages and cultivars (p< 0.001) on moisture content. Pepper berries harvested at the mature stage had significantly low initial moisture (71.6%) resulting in fewer drying days (5 days). Harvesting pepper at mature stage enhanced quality of black pepper; particularly berry colour, firmness, dry recovery, and moisture content. Farmers should therefore harvest their pepper berries at maturity peak to maximize physical and organoleptic qualities. Studies are suggested on. on quantities and qualities of volatile oils at different growth stages of pepper is recommended.
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
Diversity and efficacy of tuta absoluta (meyrick) associated entomopathogenic fungi under different tomato agro- ecological zones of Tanzania
(Sokoine University of Agriculture, 2023) Magwe, Mwamu Magwe
Tomato crop is one of the important horticultural vegetables which is used both in consumption and commercially worldwide. Insect pests are the most destructive biotic factors facing tomato production almost in the whole world. Tuta absoluta is a one of the most destructive insect which decrease tomato production and increases production cost in Tanzania and in the whole world and its economic effects globally. The management of T. absoluta by synthetic chemicals is not working properly due to resistance which is developed by of the pest .Many findings by plant researchers from different countries including Africa have been proved that the use of entomopathogenic fungi such as Beauveria bassiana, Metarhizium anisopliae, as biocontrols agent against Tuta absoluta is more efficient compare to the use of synthetic pesticides. In this study a total of twenty four soil samples were collected from tomato farms infested by Tuta absoluta, the soil samples were from different agro ecological zones of Tanzania. Culturing, Morphological, Sequencing data and results obtained showed that ten fungi were entomopathogenic fungi and fourteen were non entomopathogenic fungi among ten entomopathogenic fungi only two spp were related to Tuta absoluta management in tomato production. The entomopathogenic fungi related to Tuta absoluta control were Metarhizium spp and Aspergillus spp. Aspergillus spp is not recommended for Tuta absoluta management in tomato plants because it contains afflatoxin which is toxic to human being but it has high pathogenicity against Tuta absoluta. The pathogenicity of entomopathogenic fungi against Tuta absoluta were tested, against T. absoluta larvae, pupa, and adult stages under conditions of 19.5°C and 50%RH, 30.4°C and 70% RH, respectively, at different conidial concentrations (1.0 × 106, 1.0 × 107 , 1.0 × 108 conidial/ml) in the laboratory for twenty nine days. The factorial experiment design was used where by tomato leaflets from screen house (6 × 7 cm area) were used as experimental units that were dipped into (1.0 × 106 , 1.0 × 107 and 1.0 × 108 conidia/ml) of isolates and control (water containing 0.1% Triton X-100). Treated leaflets were dried at room temperature for elimination of excess water then was placed in Petri dishes (21 cm diameter) lined with wet paper towel and cotton covering the petiole to prevent leaf dehydration. Then, ten (10) T. absoluta larvae were inoculated separately into each of three treated leaflets and control. Each concentration was replicated three times with10 larvae. Treated leaflets were used only once at the beginning of the experiment. After 24 h, when treated leaflets are depleted, treated larvae were fed on fresh untreated leaves. Dead larvae were placed on another Petri dish lined with moist paper towel for re- isolation of fungus. Data of the larvae survival duration, number of dead larvae, number of larvae active (larvae treated but persisted), and number of adults emerged from total treated pupae, number of adult emerged was recorded at interval of 24 h and trials were monitored up to the completion of T. absoluta life cycle and lifespan. Results showed that Metarhizium anisopliae, at all concentration caused high larvae mortality rate (98.2%) followed by Aspergillus spp (71%), larvae mortality rate increased with incubation time and concentration and consequently inhibited pupation and adult emergence within a short time before the completion of the life cycle of Tuta absoluta which is 29 days. Metarhizium anisopliae reduced the life span T. absoluta adult within 5 days of post inoculation at all conidia/ml, other entomopathogenic spp (Penicillium spp, and Cladosporium spp,) were also tested against Tuta absoluta larvae, pupa and adult stages the results recoded lower pathogenicity. Penicillium spp recorded 80% of adult survival at all conidial concentration within the whole incubation time. Geotrichum candidum recorded 100% of adult survived at all conidial concentration after the incubation time. Whereas in control T. absoluta adult survived recorded 100%. This study found that Metarhizium anisopliae has the potential to be used as effective biological control against Tuta absoluta in tomato production especially at larvae stage which is the most destructive stage.
Effects of plant based fermented organic fertilizers, compost and poultry manure on tomato plant performance and root knot nematode management
(Sokoine University of Agriculture, 2023) Mziray Z. S
Tomato (Solanum lycopersicum L.) is one of the most important vegetable crops produced by small holder farmers in Tanzania. Tomato production under agroecological farming methods employs the use of natural fertilizers, biological pest control and other related approaches that ensures crop production while considering environmental and consumer health safety. Farmers practising these methods in Uponda village, Morogoro reported poor plant performance, presence of root galls and low yield in tomato in a participatory research workshop organised by Sustainable Agriculture Tanzania (SAT), held at Sokoine University of Agriculture (SUA) in December 2019. The problems reported, were associated to poor soil fertility status and root knot nematode infestation. Sustainable Agriculture Tanzania (SAT), among many other related activities, is also researching on organic methods of improving soil fertility in order to assist farmers to attain maximum productivity in sustainable manner. Root Knot Nematode (RKN), have been reported to cause significant yield reduction in tomato and is considered as of high economic importance. The use soil organic amendments in improving soil fertility and controlling root knot nematodes have been well documented. However, limited mineral composition, slow- release rate, high application rates, contamination with undesirable substances, and lack of nutritional consistence have been ongoing challenges on the use of organic fertilizers. This study aimed at evaluating the effects of plant based fermented organic fertilizers (PFOFs) developed following SAT procedures with minor improvements, on tomato growth, yield, fruit size as well as controlling root knot nematode. The improved PFOFs were tithozam (a mixture of fermented moringa, wild sunflower, and comfrey leaves) and z-mix (fermented banana peels, banana male buds and tithozam mixed in equal proportions). The exact preparation process is briefly explained in the methodology part of this work. Experiments in screen house and in open field were established at Sokoine University of Agriculture and World Vegetable Centre, Arusha for the evaluation. Same study was also established as an on-farm experiment at uponda village where the problem was reported, but due to either RKN severity or environmental condition and poor management total crop failure was observed. Treatments were poultry manure, compost manure, z-mix, tithozam and control. Test crop was tomato, variety Tanya with a yield potential of 48-64t/ha. Data were tested for normality using Kolmogorov-smirnov and Shapiro-wilk test, and made approximately normal following data cleaning and transformation (square root and arcsine) prior to data analysis. Analysis of variance (ANOVA) done by GenStat statistical package V.16 (VSN International, UK). Least Significant Difference was used as mean separation test both at p = 5%. Treatments resulted into different levels of effectiveness in improving crop performance and controlling root knot nematodes. Application of fermented organic fertilizers significantly increased tomato plant height (p=0.003), number of leaves (p=0.004), number of flowers (p=0.003), number of fruits and overall tomato yield (p=0.004) as compared to control. These fertilizers also significantly (p<0.001) reduced nematode population, reproduction index, and number of galls in tomato roots. Results obtained showed that, PFOFs had similar effects in improving plant growth, fruit size and yield compared to poultry and compost manure. There was a significant difference among tested organic fertilizers on their control in root knot nematodes in tomato. Nematode galling index differed significantly (p<.001), among tested treatments. A fermented mixture of Tithonia diversifolia, Symphytum officinale and Moringa oleifera mixture, was found to be more effective in controlling nematode. However, further research on its mode of action and optimum application rate is recommended. These findings indicate that, the PFOF formulated by SAT can be of alternative use in areas where the compost, poultry and other organic fertilizers are not available.
Optimization of natural management methods against fall armyworm (Spodoptera Frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in maize crops in Morogoro, Tanzania
(Sokoine University of Agriculture, 2023) Simon .E
Fall armyworm (FAW), Spodoptera frugiperda (J.E Smith) is a notorious pestiferous insect with wide host range, high dispersal ability and high fecundity that make it one of the most severe economic pests. It has been restricted to America and in 2016 was reported from various countries in Africa including Tanzania. Objectives of this study were (i) Evaluation of natural management methods against FAW for improved maize productivity. (ii) To evaluate the effectiveness of biopesticides- enhenced push-pull systems against FAW in selected maize cropping systems (iii) To determine the influence of cropping systems and biopesticides on parasitism rate and abundance of Parasitoids of S.frugiperda. A completely randomized design (CRD) with four replications was adopted to determine developmental biology of the FAW using bio pesticides B. thuringiensis (Bt), M. anisopliae and neem seed extract with lower dose of 2 mls, 2mls and (30g) per one litre of water respectively, tested against FAW in the laboratory. Results showed that developmental duration of FAW growth stages differed significantly among treatments. Egg incubation, larval duration, pupa stage duration and the total developmental duration were significantly longer on the biopesticides treated colony compared to untreated groups (p < 0.001). The shortest developmental duration of FAW stages were observed on control colonies at 2.1 ± 0.18, 14.88 ± 0.18, and 27.7 ± 0.34 days for egg, larva and pupa stages respectively. The longest developmental duration was observed in colonies under B. thuringiensis treatment (3.5 ± 0.37 SE, 22.03 ± 0.59 SE, 12.68 ± 0.23 SE and 37.7± 0.54 SE) days for egg, larva and pupa stages respectively. The effectiveness of biopesticides-enhenced push-pull systems against FAW in selected maize cropping systems was evaluated. A factorial experiment with treatment combination of 5 × 2 was used. Factor A included biopesticides with five levels. Factor B cropping system with two levels. Results showed significant (p ˂ 0.001) effects of cropping system and biopesticide application on FAW egg masses, abundance of FAW larvae per plant , percent damaged plant and grain yield of maize crop. However, interaction of biopesticides × sampled weeks and between cropping system × biopesticides × sampled week did not significantly influence egg masses. A total of 777 larval and 2241 egg-larval parasitoid species were collected during the 2020 – 2021 period of this study. To determine the influence of cropping systems and biopesticides on parasitism rate and abundance of Parasitoids of S.frugiperda, factor A included biopesticides with five levels (B. thuringiensis, M.anispoliae, neem seed extract, flubendiamide 480 Sc (positive control) and Maize sole crop (negative control). Factor B cropping system with two levels (Push pull technology and maize sole crop. The results showed significant effect on relative abundance of Cotesia sp (p ˂ 0.001) on plots treated with biopesticides. Results also showed significant effect of parasitism rate and relative abundance of one egg-larval parasitoid specie (C. bifoveolatus) and two larval-parasitoids species (C. luteum and Cotesia sp) (P < 0.05) on cropping system. The results also showed significant effect (P < 0.05) on parasitism rate and percentage relative abundance of one egg-larval parasitoid specie (C. bifoveolatus) and two larval- parasitoids species (C. luteum and Cotesia sp) on interaction between cropping system and biopesticides. The highest mean C. bifoveolatus was observed on maize sole crop cropping system treated with neem seed extract biopesticides and the lowest was observed on maize sole crop cropping system with no any biopesticides application, Also the highest mean of Cotesia sp was observed on Push pull technology (PPT) treated with Bacillus thurigiensis biopesticides and the lowest was observed on PPT treated with Metarhizium anisopliae. Then the highest mean of C. luteum was observed on Push pull technology treated with Bacillus thurigiensis biopesticides and the lowest was observed on PPT treated with flubendamide as negative control. The results also showed significant effects of parasitism rate for Chelonus bifoveolatus and Cotesia sp on interaction between cropping system and biopesticides application, biopesticides and sampling week. The highest mean parasitism rate of C. bifoveolatus was observed on maize sole crop cropping system treated with neem seed extract biopesticides and the lowest was observed on maize sole crop cropping system with no any biopesticides application. The highest mean of Cotesia sp was observed on Push pull technology treated with Bacillus thurigiensis biopesticides and the lowest was observed on PPT treated with Metarhizium anisopliae. No emerged parasitoid species from eggs sampled from plots treated with Flubendiamide. Overall, both biopesticides and push pull technology demonstrated potential natural control methods for the invasive fall armyworm in maize fields in Morogoro Tanzania
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.
Occurrence and farmers’ awareness on sisal bole rot disease in Muheza district, Tanzania
(Sokoine University of Agriculture, 2023) Meena, Mary Zakayo
Sisal (Agave sisalana L.) produce the world's most important natural hard fiber and Tanzania is the world's third largest producer of the fiber, accounting for more than 40% of global production. Muheza district is the second largest producer of sisal, after Korogwe district, which is the center of sisal industry in Tanzania and whose production is mainly based on rural estates and smallholders. The crop has adaptive advantages to stress conditions and pests, but bole rot is one of the main disease that causes significant damage to the crop. The disease is often associated with Aspergillus fungi and it has been a burden to the crop since 1930s. To date, there are four Aspergillus species recognized as the causal agents of the disease; A. niger, A. welwitschia, A. brasiliensis and A. tubingensis, but the predominant agent is A. niger. The infection of fungi to sisal plantlets and matured sisal plants results into death of plants, reducing its quality and quantity. In Tanzania, no research has been conducted to assess farmers’ level of awareness neither on sisal bole rot disease or on the assessment of disease incidence and severity in farmers' field. This study aimed at determining farmers’ level of awareness of bole rot disease and disease incidence and severity in farmers’ sisal farms at three wards found in different agro-ecologies in Muheza district. A questionnaire was used in obtaining information from 71 small scale sisal farmers and three sisal estates found in Muheza district. Assessment of disease incidence and severity was conducted at the same wards, where three smallholders and one sisal estate at each ward were randomly selected by systematic sampling. A one hectare farm per small scale farmer and per estate was measured and studied during dry and rainy seasons in the same sisal farms. Majority of sisal farmers (68.92%) had moderate (39-71%) level of awareness of bole rot disease whilst 6.76% of sisal farmers had low (0-38%) level of awareness. The farmers lack in-depth knowledge regarding sisal bole rot disease probably because most of them (89.19%) rely on their fellow sisal farmers’ to obtain information on sisal production and on bole rot disease. More than half (72.9%) of the farmers, their sisal fields were affected by bole rot disease presumably due to the use of infected planting materials. The disease was found in all studied wards at different intensity possibly because of diverse climatic conditions and low altitude predominant in the surveyed wards. Kigombe ward located at low altitude had high disease incidence (36.43%), severity (32.54%) and disease intensity index of (42.40) while Tanganyika ward found in high altitude had low disease incidence (19.09%), severity (12.82%) and disease intensity index of 90.4. The development of bole rot disease was higher during wet season than during dry season in both surveyed wards and Kigombe ward had the highest disease incidence (46.46%) and severity (40.24%) probably because it is found in low land with flat areas which get flooded during heavy rainfall, a conducive environment for fungal infection, growth and reproduction. It was noted that all sisal growers (100%) still use unhealthy sisal planting materials namely suckers from previous crop to raise their new crop possibly due to lack of bole rot awareness and money. Education is important for improving farmers’ awareness regarding sisal production and management of bole rot disease. A prepared comprehensive training module on sisal production practices with management practices of bole rot disease should be introduced to sisal farmers as a way of increasing their awareness on sisal production and management of bole rot disease. Efforts are needed to improve farmers to access healthy planting materials through effective distribution. Nurseries for the production of healthy sisal seedlings should be set up in each ward to facilitate farmer access and reduce transport costs. However, further studies to assessing farmers’ level of awareness on bole rot disease and on the determination of disease intensity should be done in this and other sisal growing areas in Tanzania.
Optimization of natural management methods against fall armyworm (Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in maize crops in Morogoro, Tanzania
(Sokoine University of Agriculture, 2023) Simon, Erick
Fall armyworm (FAW), Spodoptera frugiperda (J.E Smith) is a notorious pestiferous insect with wide host range, high dispersal ability and high fecundity that make it one of the most severe economic pests. It has been restricted to America and in 2016 was reported from various countries in Africa including Tanzania. Objectives of this study were (i) Evaluation of natural management methods against FAW for improved maize productivity. (ii) To evaluate the effectiveness of biopesticides-enhanced push-pull systems against FAW in selected maize cropping systems (iii) To determine the influence of cropping systems and biopesticides on parasitism rate and abundance of Parasitoids of S.frugiperda. A completely randomized design (CRD) with four replications was adopted to determine developmental biology of the FAW using bio pesticides B. thuringiensis (Bt), M. anisopliae and neem seed extract with lower dose of 2 mls, 2mls and (30g) per one litre of water respectively, tested against FAW in the laboratory. Results showed that developmental duration of FAW growth stages differed significantly among treatments. Egg incubation, larval duration, pupa stage duration and the total developmental duration were significantly longer on the biopesticides treated colony compared to untreated groups (p < 0.001). The shortest developmental duration of FAW stages were observed on control colonies at 2.1 ± 0.18, 14.88 ± 0.18, and 27.7 ± 0.34 days for egg, larva and pupa stages respectively. The longest developmental duration was observed in colonies under B. thuringiensis treatment (3.5 ± 0.37 SE, 22.03 ± 0.59 SE, 12.68 ± 0.23 SE and 37.7± 0.54 SE) days for egg, larva and pupa stages respectively. The effectiveness of biopesticides-enhanced push-pull systems against FAW in selected maize cropping systems was evaluated. A factorial experiment with treatment combination of 5 × 2 was used. Factor A included biopesticides with five levels. Factor B cropping system with two levels. Results showed significant (p ˂ 0.001) effects of cropping system and biopesticide application on FAW egg masses, abundance of FAW larvae per plant , percent damaged plant and grain yield of maize crop. However, interaction of biopesticides × sampled weeks and between cropping system × biopesticides × sampled week did not significantly influence egg masses. A total of 777 larval and 2241 egg-larval parasitoid species were collected during the 2020 – 2021 period of this study. To determine the influence of cropping systems and biopesticides on parasitism rate and abundance of Parasitoids of S.frugiperda, factor A included biopesticides with five levels (B. thuringiensis, M.anisopliae, neem seed extract, flubendiamide 480 Sc (positive control) and Maize sole crop (negative control). Factor B cropping system with two levels (Push pull technology and maize sole crop. The results showed significant effect on relative abundance of Cotesia sp (p ˂ 0.001) on plots treated with biopesticides. Results also showed significant effect of parasitism rate and relative abundance of one egg-larval parasitoid specie (Cbi foveolatus) and two larval-parasitoids species (C. luteum and Cotesia sp) (P < 0.05) on cropping system. The results also showed significant effect (P < 0.05) on parasitism rate and percentage relative abundance of one egg-larval parasitoid specie (Cbi foveolatus) and two larval- parasitoids species (C. luteum and Cotesia sp) on interaction between cropping system and biopesticides. The highest mean Ci foveolatus was observed on maize sole crop cropping system treated with neem seed extract biopesticides and the lowest was observed on maize sole crop cropping system with no any biopesticides application, Also the highest mean of Cotesia sp was observed on Push pull technology (PPT) treated with Bacillus thuringiensis biopesticides and the lowest was observed on PPT treated with Metarhizium anisopliae. Then the highest mean of C. luteum was observed on Push pull technology treated with Bacillus thuringiensis biopesticides and the lowest was observed on PPT treated with flubendiamide as negative control. The results also showed significant effects of parasitism rate for Chelonus bifoveolatus and Cotesia sp on interaction between cropping system and biopesticides application, biopesticides and sampling week. The highest mean parasitism rate of Cbi foveolatus was observed on maize sole crop cropping system treated with neem seed extract biopesticides and the lowest was observed on maize sole crop cropping system with no any biopesticides application. The highest mean of Cotesia sp was observed on Push pull technology treated with Bacillus thuringiensis biopesticides and the lowest was observed on PPT treated with Metarhizium anisopliae. No emerged parasitoid species from eggs sampled from plots treated with Flubendiamide. Overall, both biopesticides and push pull technology demonstrated potential natural control methods for the invasive fall armyworm in maize fields in Morogoro Tanzania.
Bean bruchid resistance and genetic diversity of bruchid ecotypes from bean growing regions of Tanzania
(Sokoine University of Agriculture, 2022) Mayunga Edina
Bean bruchids Zabrotes subfasciatus and Acanthoscelides obtectus are the serious pests which cause serious damage to the stored beans. Damage is directly related to the time of bean storage, the longer storage time the greater the damage. Host plant resistance is a profitable and a safe alternative to control bruchids in common bean and is associated with biochemical, morphological, and molecular traits. These traits affect insect growth and development and in that way, reduce the losses by the pests. The aim of first objective was to evaluate the damage level of bruchids in resistant (AO-1012-29-3-3A) and susceptible (Njano gololi) bean genotypes associated with biotype variation. Bean bruchids were collected from different bean growing regions Songwe (Vwawa), Kilimanjaro (Mungushi), Karatu (Rhotia), Morogoro (SUA) and Arusha (Kimyaki) in Tanzania, then transferred to the laboratory for inoculation. . Experiment was conducted using a Completely Randomized Design (CRD) with a 2 x 5 factorial scheme, two bean cultivars (AO-1012-29-3-3A and Njano gololi), five bruchids ecotypes for each A. obtectus and Z. subfasciatus and 3 replications. The results of this study have reported that each bean bruchids from a specific region showed a significant difference at prob. = 0.001 on beans infestation. AO-1012-29-3-3A and Njano showed different results on the resistance to bean bruchids. It was observed that AO-1012-29-3-3A line was resistant to bruchids collected from many regions by experiencing less damage and Njano gololi was observed to have high population of emerged bean bruchids, high percentage weight loss, high Susceptibility index and severity hence susceptible. The purpose of second objective was to determine phenotypic characteristics of the emerged F 1 bruchid ecotypes resulted from crossing resistant (AO-1012-29-3-3A) and susceptible (Njano gololi) bean genotypes. To examine whether these traits are host induced or genetically determined. Resistant genotype was used to assess whether host-race morphological differences are genetically determined or due to phenotypic plasticity. There was significant difference in size of F 1 bruchids emerging from resistant genotype (AO-1012-29-3-3A) and susceptible genotype (Njano gololi). The results showed that the morphological change of F 1 bruchids from AO-1012-29-3-3A was due to phenotypic plasticity since morphological changes occurred due to feeding on resistant genotypes (environment factor). The purpose of third objective was to identify the genetic diversity of bean bruchid weevils (Acanthoscelides obtectus and Zabrotes subfasciatus) in bean producing regions in Tanzania using molecular taxonomy (12S rRNA and COI marker). The results obtained did not show genetic diversity (100% identity) of Acanthoscelides obtectus present in Tanzania. For Zabrotes subfasciatus some variations was observed (80.2% identity). The genetic diversity was observed between Acanthoscelides obtectus and Zabrotes subfasciatus in which there was difference in some sequence alignment. Better knowledge of bruchids diversity present in Tanzania will help breeders and farmers to propose effective control methods with impact on environmental changes.
Optimization of natural management methods against fall armyworm (Spodoptera frugiperda (j.e. smith) (lepidoptera: noctuidae) in maize crops in Morogoro, Tanzania
(Sokoine University of Agriculture, 2023) Erick Simon
Fall armyworm (FAW), Spodoptera frugiperda (J.E Smith) is a notorious pestiferous insect with wide host range, high dispersal ability and high fecundity that make it one of the most severe economic pests. It has been restricted to America and in 2016 was reported from various countries in Africa including Tanzania. Objectives of this study were (i) Evaluation of natural management methods against FAW for improved maize productivity. (ii) To evaluate the effectiveness of biopesticides- enhenced push-pull systems against FAW in selected maize cropping systems (iii) To determine the influence of cropping systems and biopesticides on parasitism rate and abundance of Parasitoids of S.frugiperda. A completely randomized design (CRD) with four replications was adopted to determine developmental biology of the FAW using bio pesticides B. thuringiensis (Bt), M. anisopliae and neem seed extract with lower dose of 2 mls, 2mls and (30g) per one litre of water respectively, tested against FAW in the laboratory. Results showed that developmental duration of FAW growth stages differed significantly among treatments. Egg incubation, larval duration, pupa stage duration and the total developmental duration were significantly longer on the biopesticides treated colony compared to untreated groups (p < 0.001). The shortest developmental duration of FAW stages were observed on control colonies at 2.1 ± 0.18, 14.88 ± 0.18, and 27.7 ± 0.34 days for egg, larva and pupa stages respectively. The longest developmental duration was observed in colonies under B. thuringiensis treatment (3.5 ± 0.37 SE, 22.03 ± 0.59 SE, 12.68 ± 0.23 SE and 37.7± 0.54 SE) days for egg, larva and pupa stages respectively. The effectiveness of biopesticides-enhenced push-pull systems against FAW in selected maize cropping systems was evaluated. A factorial experiment with treatment combination of 5 × 2 was used. Factor A included biopesticides with five levels. Factor B cropping system with two levels. Results showed significant (p ˂ 0.001) effects of cropping system and biopesticide application on FAW egg masses, abundance of FAW larvae per plant , percent damaged plant and grain yield of maize crop. However, interaction of biopesticides × sampled weeks and between cropping system × biopesticides × sampled week did not significantly influence egg masses. A total of 777 larval and 2241 egg-larval parasitoid species were collected during the 2020 – 2021 period of this study. To determine the influence of cropping systems and biopesticides on parasitism rate and abundance of Parasitoids of S.frugiperda, factor A included biopesticides with five levels (B. thuringiensis, M.anispoliae, neem seed extract, flubendiamide 480 Sc (positive control) and Maize sole crop (negative control). Factor B cropping system with two levels (Push pull technology and maize sole crop. The results showed significant effect on relative abundance of Cotesia sp (p ˂ 0.001) on plots treated with biopesticides. Results also showed significant effect of parasitism rate and relative abundance of one egg-larval parasitoid specie (C. bifoveolatus) and two larval-parasitoids species (C. luteum and Cotesia sp) (P < 0.05) on cropping system. The results also showed significant effect (P < 0.05) on parasitism rate and percentage relative abundance of one egg-larval parasitoid specie (C. bifoveolatus) and two larval- parasitoids species (C. luteum and Cotesia sp) on interaction between cropping system and biopesticides. The highest mean C. bifoveolatus was observed on maize sole crop cropping system treated with neem seed extract biopesticides and the lowest was observed on maize sole crop cropping system with no any biopesticides application, Also the highest mean of Cotesia sp was observed on Push pull technology (PPT) treated with Bacillus thurigiensis biopesticides and the lowest was observed on PPT treated with Metarhizium anisopliae. Then the highest mean of C. luteum was observed on Push pull technology treated with Bacillus thurigiensis biopesticides and the lowest was observed on PPT treated with flubendamide as negative control. The results also showed significant effects of parasitism rate for Chelonus bifoveolatus and Cotesia sp on interaction between cropping system and biopesticides application, biopesticides and sampling week. The highest mean parasitism rate of C. bifoveolatus was observed on maize sole crop cropping system treated with neem seed extract biopesticides and the lowest was observed on maize sole crop cropping system with no any biopesticides application. The highest mean of Cotesia sp was observed on Push pull technology treated with Bacillus thurigiensis biopesticides and the lowest was observed on PPT treated with Metarhizium anisopliae. No emerged parasitoid species from eggs sampled from plots treated with Flubendiamide. Overall, both biopesticides and push pull technology demonstrated potential natural control methods for the invasive fall armyworm in maize fields in Morogoro Tanzania.

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