Enhancement of yield in groundnut following the imposition of transient soil-moisture-deficit stress during the vegetative phase

Transient soil-moisture-deficit stress was imposed on groundnut (Arachis hy pogaea) at three phenophases for different durations: long stress in the ea rly vegetative phase (20 days after sowing); moderate stress in the early v egetative phase (20 days after sowing); stress at flowering (40 days after sowing); and stress at pod development (60 days after sowing). Stress was i mposed for 30 or 25 days at the vegetative stage. Transient soil-moisture-d eficit 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 synchroni zed flowering. This factor contributed to a greater efficiency of conversio n of flowers to pods and to higher pod yields. Total biomass accumulation w as also higher in plants which experienced stress in the vegetative phase. Groundnut pod yields were increased by imposing a transient soil-moisture-d eficit stress in the vegetative phase for 25 days, followed by two irrigati ons at an interval of 5 days. Thus stress in the vegetative phase was benef icial for groundnut growth and pod yields, but was highly detrimental when imposed at flowering and pod development.