Dissertation
Grain legumes and cereals are widely grown in many semi-arid areas of the tropics by smallholder farmers who derive from the crops multiple benefits such as nutritious food, soil fertility, and household income. Communities in these areas are highly vulnerable to weather and other natural disaster-related challenges thus facing a problem of low crop productivity. Field experiments were conducted during the 2019-2020 cropping season in different sub agro-ecologies of central Tanzania aiming to: - (i) identify legume and cereal genotypes of higher productivity in varying potential agro-ecologies (ii) determine the stability and GxE interaction of the legume and cereal genotypes in the different agro-ecologies (iii) identify relatively more efficient and productive cropping system in varying potential agro-ecologies of central Tanzania.
Methods
Experiments were laid down in two villages of each potential agro-ecology following an incomplete randomized block design with farmers as replications. Grain yield, yield components and growth data on fourteen genotypes in total of the four crops (groundnut, pigeon pea, sorghum and pearl millet) were collected and Land equivalent ratios (LERs) calculated for intercrops amongst the crops.
Findings
Results from the experiments generally revealed that G x M x E interactions were insignificant (p ≤ 0.05) in terms of grain yield for all the crop genotypes studied. For groundnut and pigeon pea genotypes, significant differences (p ≤ 0.05) were observed across the sub-ecologies while significant genotypic effects were observed in both sorghum and pearl millet genotypes. Genotype ICGV-SM 05650 of groundnut had the highest grain yield of 2105.08 kg ha-1, while ICGV-SM 02724 recorded the lowest grain yield of 1538.87 kg ha-1 in the high potential sub-ecology. Pearl millet genotype IP 8774 had the highest yield of 1049.4 kg ha-1 and the local check had the lowest yield of 388.9 kg ha-1. Though non-significant differences (P ≤ 0.05) among genotypes tested for grain yield were observed in pigeon pea and sorghum genotypes however, pigeon pea genotype ICEAP 00040 had a slightly higher grain yield of 779.17 kg ha-1 compared to ICEAP 00557 with 770.83 kg ha-1 grain yield and sorghum genotype GAMBELLA 1107 outperformed the other genotypes with grain yield of 1420.8 kg ha-1 followed by IESV 23010 DL of 1038.0 kg ha-1. Early planting outperformed late planting for the crop genotypes tested however, non-significant differences (p ≤ 0.05) in planting dates were observed. Furthermore, crop genotypes in the high potential generally out performed those under the moderate and low potential sub-ecologies. In terms of LERs, pigeon pea - sorghum, pigeon pea - groundnut and pigeon pea - pearl millet intercrops had higher LER values of 1.59 (high), 1.65 (moderate) and 2.36 (low potential agro-ecologies), respectively compared to LERs of 1.00 in their respective sole crops.
Conclusion
Findings of the study revealed that generally elite materials outperformed the local landraces. Furthermore, intercropping systems proved to be more efficient and productive compared to sole cropping systems. From the above findings, ICGV-SM 05650 (groundnut), ICEAP 00040 (pigeon pea), GAMBELLA 1107 (sorghum) and IP8774 (pearl millet) were recommended for deployment in these varying potential agro-ecologies due to their stable and superior performance in terms of grain yield. Intercrops Pigeon pea - Sorghum, Pigeon pea - Groundnut and Pigeon pea - Pearl millet were the more efficient and productive cropping systems therefore recommended for deployment in the high, moderate and low potential agro-ecologies respectively.
International Crops Research Institute for the Semi-Arid Tropics (ICRISAT)-MALAWI