Response of Nodulating and Non-Nodulating Peanuts to Foliarly Applied Nitrogen¹

Field experiments were conducted on Lakeland sand (Thermic, coated Typic Quartz-ipsaments) during 1981-82 to determine the effect of foliarly applied N on yield, grade, and N, P, K, Ca, and Mg concentration of leaves and seed of nodulating and non-nodulating peanut (Arachis hypogaea L.).

Nodulating cultivars; Florunner, Early Bunch, and Tifrun, and three non-nodulating experimental lines were sprayed 0, 1, 2 or 4 times at 13.5 kg N/ha beginning 28 days after emergence. Foliar application of N increased the yield of Florunner, Tifrun, and all non-nodulating lines, but had no effect on Early Bunch. The addition of N to non-nodulating peanut increased the percent fancy pods, extra large kernels, and weight of seed. Seed N concentration of non-nodulating lines increased with higher rates of N, but was higher in the nodulating cultivars. Seed of non-nodulating lines contained higher levels of P, K, and Mg than seed of nodulating lines. Nodulating lines had higher concentration of leaf N than did non-nodulating lines. The leaves of the non-nodulating lines contained higher levels of P, Ca, and Mg than those of the nodulating cultivars; whereas levels of K were higher for nodulating lines.