Enhancement of Yield in Groundnut Following the Imposition of Transient Soil-Moisture-Deficit Stress During the Vegetative Phase

Abstract

Transient soil-moisture-deficit stress was imposed on groundnut (Arachis hypogaea) at three phenophases for different durations: long stress in the early vegetative phase (20 days after sowing); moderate stress in the early vegetative phase (20 days after sowing); stress at flowering (40 days after sowing); and stress at pod development (60 days after sowing). Stress was imposed for 30 or 25 days at the vegetative stage. Transient soil-moisture-deficit stress, at all phenophases, reduced the production of flowers. Soil-moisture-deficit stress for 25 days at the vegetative phase followed by two relief irrigations at an interval of 5 days, resulted in closely synchronized flowering. This factor contributed to a greater efficiency of conversion of flowers to pods and to higher pod yields. Total biomass accumulation was also higher in plants which experienced stress in the vegetative phase. Groundnut pod yields were increased by imposing a transient soil-moisture-deficit stress in the vegetative phase for 25 days, followed by two irrigations at an interval of 5 days. Thus stress in the vegetative phase was beneficial for groundnut growth and pod yields, but was highly detrimental when imposed at flowering and pod development.