[01] Dennis Iorkor, Department of Plant Breeding and Seed Science, Federal University of Agriculture, Makurdi, Nigeria. [02] Peter Egwuonwu Odo, Department of Plant Breeding and Seed Science, Federal University of Agriculture, Makurdi, Nigeria. [03] Titus Saanmoiyol Msaakpa, Department of Plant Breeding and Seed Science, Federal University of Agriculture, Makurdi, Nigeria.

A screen house experiment was conducted at the Teaching and Research Farm of the Federal University of Agriculture, Makurdi, Benue state during the 2019 cropping season to investigate the effects of soil water deficit on the growth and yield of soybean genotypes in Makurdi. The experiment was made up of three soybean genotypes (TGX-1448-2E, TGX-1835-10E and TGX-1951-3F) which were subjected to water deficit at three different growth stages which included early vegetative, 50% flowering and early pod filling with a well-watered treatment to serve as control. The experiment was conducted in a Completely Randomized Design (CRD) with three replications. Vegetative attributes evaluated were number of leaves per plant, number of branches per plant, plant height, and dry matter production at 3, 5 and 7 weeks after sowing (WAS). Yield parameters evaluated were number of pods per plant, number of aborted pods per plant, number of seeds per pod, number of seeds per plant and 100-seed weight. Analysis of variance (ANOVA) revealed significant (p≤0.05) effect of water deficit on all vegetative and yield attributes. Water deficit at early vegetative ontogeny significantly (p≤0.05) reduced number of leaves per plant, number of branches per plant, plant height and plant dry matter at 3, 5 and 6 WAS. TGX-1835-10E produced significantly highest number of leaves per plant, number of branches per plant and plant dry matter compared to the other two genotypes. TGX-1448-2E however produced significantly tallest plants among the three genotypes. Water deficit at early pod filling stage significantly reduced the number of pods per plant, number of aborted pods per plant, number of seeds per pod, number of seeds per plant and 100-seed weight. TGX-1835-10E tolerated water deficit more than TGX-1448-2E and TGX-1951-3F in all yield attributes except in 100-seed weight in which TGX-1448-2E was superior.

Deficit, Genotype, Ontogeny, Stress, Yield

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