Influence of water stress on growth and yield components of selected pigeonpea genotypes

Drought and high temperature mostly influence growth and development of pigeonpea, resulting in forced maturity. Though these stresses have a drastic impact on reducing productivity of pigeonpea, limited efforts have been made towards development of pigeonpea genotypes having tolerance to these abiotic stresses. Therefore, this study was carried out to identify pigeonpea genotypes that can tolerate water stress. A greenhouse experiment was conducted at Upper Kabete field station of the University of Nairobi, Kenya, using fifteen selected pigeonpea genotypes based on ICRISAT descriptors. The fifteen plants were grown under drought stress levels of 40% and 80% field capacity (FC) in comparison to non-drought stress (100% FC) condition in a randomized complete block design with a factorial arrangement with three replications. Data was collected on plant growth, physiological and yield attributes. Drought stress reduced 100 seed weight by 14.9 %, number of pods (31.9%) and pod diameter (25%). At the lowest moisture level (40 % FC), drought stress reduced pod weight by 84 %, pod length (2 %), Chlorophyll content (11.9 %) and shell weight (2.4 %). However, reduction of moisture level to 80% FC recorded an increase in pod weight (5.5 %) and pod length (3.4 %) and no significant effect on chlorophyll content and number of seeds per pod. Genotypes ICEAPs 182022, 182014, 182013, 19023 and 86012 performed better in relation to growth and yield despite the increased levels of drought stress. The few identified genotypes can be utilized as potential parents in breeding for drought tolerance.