Scheduling irrigations for summer groundnut (Arachis hypogaea)

An experiment was conducted at Bilaspur during summer seasons of 1994 and 1 995 to study the effect of irrigation levels on kernel yield, nutrient upta ke and oil yield of groundnut (Arachis hypogaea L.). Irrigating summer grou ndnut at an 0.8 IW : CPE ratio (irrigation at 75 mm CPE) gave significantly higher pods/plant, kernel yield and oil yield and resulted in higher uptak e of N, P and K by the plants over 0.6 IW: CPE ratio (irrigation at 100 mm CPE). Irrigations scheduled under 1.0 and 1.2 IW : CPE ratio had no further advantage over an 0.8 IW : CPE ratio. Stress-day index concept proved usef ul to schedule irrigation in summer groundnut. Water-use efficiency (WUE), net and additional returns and input:output ratio were highest with an 0.8 IW : CPE ratio irrigation schedule.