Response of Early Bunch Peanuts to Calcium and Potassium Fertilization¹

There is an immediate need for fertilization data concerning any newly released cultivar of peanuts (Arachis hypogaea L.). Field studies were conducted on three soil types to determine the effect of various rates of Ca and K on yield, quality and certain peanut diseases of the new peanut cultivar, Early Bunch. Calcium was applied at rates of 0, 123, 246 and 369 kg/ha and K was applied at levels of 0, 112 and 224 kg/ha. Fertilizer treatments were arranged in randomized block design with four replications. Yields, sound mature kernels (SMK), extra large kernels (ELK), and Pythium population and Sclerotium rolfsii (disease loci) incidence were determined. The yield, SMK, and ELK of Early Bunch peanuts were increased by Ca fertilization on Fuquay and Tifton loamy sand, but not on the Greenville sandy loam. The application of high levels of K reduced the yield of Early Bunch peanuts on Fuquay soil but had no effect on Tifton or Greenville soils.

Increased Ca fertilization increased soil Ca on Greenville and Tifton soils but not on Fuquay soil. Potassium fertilization increased soil K on the Greenville soil but not on the Fuquay and Tifton soils. Some evidence was obtained that Ca fertilization reduced average Pythium (total) population in the Tifton and Fuquay soils and increased average incidence of Sclerotium rolfsii.