Evaluation of soybean varieties for adaptation and response to inoculation in southern highlands of

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1 //4 Evalua of soybean varieties for adapta and response to inocula in southern highlands of Tanzania Aida Magelanga Background Soil fertility and low yielding varieties are the most important constraint to soybean produc In SHT, 77% of agricultural soils have very low to low N content Biological nitrogen fixa by soybean is an important op for increasing soil N. Cont ARI-Uyole has released 4 soybean varieties but their response to rhizobia inocula remain unknown. Breeding program in East and Southern Africa have developed and release soybean varieties with good attributes (high yielding, resistant to pest and disease, tolerant to drought, and with quality attributes) which are relevant to Southern Tanzania. The project is aimed at evaluating the released and introduced varieties for wider adaptability and response to rhizobia inocula. The aim is diversify soybean germplasm in Tanzania to suit different needs. Objectives To assess the performance of released and introduced soybean varieties under different agro ecological condis of southern highlands of Tanzania To determine the response of soybean varieties to rhizobium inocula in different soils of southern highlands. To evaluate the biophysical condis determining the performance of soybean and response to inocula. To produce dissemina tools Activities Sites selec, field prepara, planting, trial management, data collec, processing and report writing Produce promoal materials. Study areas On farm : Mawengi and Mkiu in Ludewa district On sta : ARI-Uyole and Mbimba in Mbeya and Mbozi districts; respectively Suluti in Namtumbo district. Materials Varieties: Soybean Varieties Source Uyole Soya, Uyole Soya, ARI-Uyole,,,, Seed Co Namsoy 4M Makerere University TGx94-6F and TGx74-F IITA-Kenya Maize variety UH 65 ARI Uyole Fertilizer: TSP at kg P/ha UREA at kg N/ha Rhizobia inoculant: Legume fix at 5g per 5 kg of seeds

2 //4 Methodology Design: Split split-plot, replicated three times. Main plots: locas Subplot: Rhizobia (inoculated and noninoculated) Sub-sub plot: soybean varieties and control (Uyole+ P + N) Plot size:.7 x m Spacing for soybean:.45 x.5 m. Spacing for maize:.75 x. m Agronomic practices Planting January 4 by drilling in furrows. TSP at 6 kg P/ha., UREA at kg N/ha. Legume fix + soybean at 5g per 5 kg of seeds inoculated treatments. Maize : reference crop. ARI Uyole, pests by selecron. Weeding : three times Biomass sampling, nodula assessment and N determina: At seed initia 5 plants sampled for biomass, BNF and nodula. Dried shoots ground and total N using NDM by Peoples et al. (989). %N from N-fixa = x [(Ntfp Ntnp)/Ntfp]) Data collected: Before planting: Site characteriza, Soil physical and chemical properties, After planting: Crop establishment, nodule score, biomass, days to 5% flowering, podding and maturity, pest, diseases, N content and yield. Analysis done using Genstat statistical package version 4 released in RESULTS AND DISCUSSION TABLE : SOIL CHARACTERISTICS ARI Table : Site characteriza Parameter Physical properties t ion S/n Site AEZ Descrip of Landform Posi Eleva Crops grown Fertilizer (m.a.s.l) in last three applied seasons S: Nil Nil Mkiu 5 Steeply dissected to E:.554 mountainous S: Nil Nil Mawengi 5 Steeply dissected to E:4.55 mountainous S:.5485; 868 Sunflower, TSP, UREA and Suluti 6 Hilly to steeply dissected land E: 6,7795 maize SA with rock outcrop % Clay Sandy Sandy clay clay %Sand Loam Clay Sandy Loam % Silt Sandy clay loam clay Chemical properties Slightly Soil ph (:5) H O %TotalN.8 Very low. Low. Low. Low.8 Very low Extractable P mgkg Mbimba Undulating rolling with rift S: 9.887; benches E: maize TSP and CAN % Organic Carbon.54.8 Low.9.74 High. CEC(cmol c (+) kg High 7. High 6 5 ARI- Undulating rolling lava plain S: E: Soybean, sunflower and beans DAP, CAN and UREA Calcium(me/g).75 Low.54 Low.48 Very low.68 Low.6 Low Iron (mg/kg).9 Low.95 Low.8 Low Low.9 Low Manganese (mg/kg).78 Low.58 Low.6 Low.7 Low.8 Low Days to 5% flowering Days 4 TGx 74 -F TGx 94-6F Uyole Sulut Mbimba Mawengi Mkiu

3 //4 Nodule assessment Nodula response of soybean varieties 4 5 Nodule score Uyole Mbimba Mawengi Suluti Mkiu TGx 74 -F TGx 94-6F Dry matter 6 8 Nitrogen content (t/ha) % N 5 4 TGx 74 -F TGx 94-6F TGx 74 -F TGx 94-6F

4 //4 Pest damaged plants at ARI Uyole Diseased plants at Mbimba 4 Bacterial blight Rust.5 score.5.5 Score TGx 74 -F TGx 94-6F.5 TGx 74 -F TGx 94-6F Tria sites.5 Yield response of soybean varieties to inocula in southern Highlands Yield response of soybean varieties to inocula yield t/ha.5 yield t/ha.4. Varieties with TGx 74 -F TGx 94-6F.8.6 Varieties without.5.4 with without with Without with Without with Without with Without ARI. White flower Namsoy- TGx TGx 4m 74 -F 94-6F Soybean varieties 4

5 //4.5 General performance of soybean varieties across all sites Produc of dissemina tools Yield t/ha.5.5 ARI Uyole Suluti Mbimba Mawengi Mkiu Two leaflets each copies on Tumia vichochezi kuongeza rutuba ya udongo and Kanuni za kilimo bora cha soya..5 White flower Namsoy- TGx 74 TGx 94 4m -F -6F Soybean varieties One flier copies titled Vichochezi vya rutuba ya udongo. Conclusion and recommendas The materials performed differently across all sites. Study showed positive response to rhizobia at all sites though at different levels. Further evalua of the varieties need to be done to identify materials suitable for specific zone. Further sensitiza on importance, utiliza of inoculant need to be done for wider dissemina and adop of the technology. Further studies need to be done on marketing and marketing channels of soybean for wider adoptability. Social economic studies need to be done on the soybean and inoculant technologies. In order to have sustainable supply, of inoculant, the project recommends the government to officiate use of qualitable inoculants. In depth evalua of identifying pest species need to be done at ARI Uyole for pest characteriza. 5