Effect of Gypsum on Yield, Grade and Incidence of Pod Rot in Five Peanut Cultivars1

Abstract

Abstract Five cultivars of peanuts, (Arachis hypogaea L.), Florunner, Tifrun, Florigiant, Ga. 194 Va. and Early Bunch, were grown at Tifton, Ga. on a Stilson loamy sand, low in calcium (356 kg/ha), and at Plains, Ga. on a Greenville sandy loam, relatively higher in calcium (752 kg/ha), for three years (1977–79) to study the response of yield, grade and incidence of pod rot with applications of gypsum. Plots were topdressed with 0, 560, 1120, or 1680 kg/ha of gypsum. Pod rot did not occur at Plains and no significant difference occurred among gypsum rates for yield, percentages of sound mature kernels (SMK), extra large kernels (ELK), and value/ha for any cultivar. However, significant differences were detected for these variables among cultivars. At Tifton, severe pod rot occurred on plots receiving no gypsum, but the severity decreased for all cultivars as the rate of gypsum applied was increased. Differences in yield, percentages of SMK, ELK, pod rot, value/ha and kernel calcium occurred among cultivars, grown at different gypsum rates. Florunner was significantly higher in yield, percent SMK, and value/ha than the other cultivars at all gypsum rates, and significantly lower in pod rot at 0 and 560 kg/ha gypsum. The amount of calcium in kernels increased for most cultivars as rates of gypsum increased. These data support previous work which indicated a suppression of pod rot and an increase in yield and kernel calcium with applications of gypsum.