EFFECT OF DROUGHT AT DIFFERENT REPRODUCTIVE STAGES ON YIELD AND YIELD COMPONENTS OF SOME COWPEA (VIGNA UNGUICULATA L. WALP) VARIETIES IN LAPAI, NIGER STATE, NIGERIA
Drought is one of the most unfavorable abiotic factors that can affect the growth and yield of cowpea. Drought at different reproductive stages can interfere with the morphological processes of plants. Therefore this research aim to determine the effect of drought at different reproductive stages on yield and yield components of some cowpea varieties. A screen house experiment was conducted at the Botanical Garden of Biological Science Department, Ibrahim Badamasi Babangida, University during the 2022 cropping season The three cowpea varieties used were; FUAMPEA 1, FUAMPEA 2 and ITK89KD-288 which were planted and subjected to water stress at three different reproductive stages which included; early flowering stage, early pod set stage, early seed filling stage and a well-watered treatment to serve as control. The treatments were arranged in a Complete Randomized Design (CRD) in three replications. Cowpea yield attributes evaluated were; number of pods per plant, pod length, pod weight per pot, number of seeds per pod, 100 seed weight, total grain yield per pot and estimated grain yield per hectare. Results revealed that variety was highly significant (p≤0.01) for pod length, total grain yield per pot and estimated grain yield per hectare. On the other hand, drought was significant (p≤0.05) for pod weight per pot. Variety however was not significant for number of pods per plant, number of seeds per pod and 100 seed weight. Drought showed a highly significant effect (p≤0.01) on number of pods per plant, pod length, pod weight per pot, number of seeds per pod, 100 seed weight, total grain yield per pot and estimated grain yield per hectare. Water stress at early seed filling stage significantly reduced total grain yield per plot and total grain yield per hectare. Drought at different reproductive stages affects the morphological and physiological processes of cowpea as a crop. This is an indication that water is very crucial during the growth and yield of cowpea.