Irrigation and Tillage Effects on Peanut Yield in Virginia1

Abstract

Abstract During crop years 1980–1983, a field study was conducted in southeastern Virginia on a Norfolk loamy fine sand soil to evaluate the effect of irrigation, underrow ripping, and seedbed preparation methods on peanut yields. The seedbeds were prepared conventionally (flat), with a rotary tiller and bed shaper, with a disk bedder, and with a rolling cultivator. Irrigation increased peanut yield only for crop year 1980 peanuts when there was a severe drought. Irrigation decreased yields for the other 3 years when rainfall was near normal. Some of the decrease in yields with irrigation can be attributed to an increase in the severity of several diseases including leafspot, pod rot, and Sclerotinia blight. Underrow ripping and seedbed preparation methods had no significant effect on yield and crop values. The effect of an interaction between underrow ripping and irrigation was indicated. Results from this study and previous studies indicated that underrow ripping does not appear to be an advantageous tillage operation for use in peanut production systems in the Virginia-Carolina area. Comparisons of seedbed preparation methods do not suggest that one method was superior to another method. The inconsistent trends in seedbed methods between years can be attributed to elements other than irrigation or underrow ripping treatments. Further studies need to define irrigation methods and amount of irrigation water to apply for efficient peanut production.