Peanut Pod Rot Complex: A Geocarposphere Nutrient Imbalance

Publisher Website
Google Scholar
Abstract
Gypsum (CaSO4 .cntdot. 2H2O), magnesium sulfate (MgSO4), potassium sulfate (K2SO4), ammonium nitrate (NH4NO3), and gypsum + magnesium sulfite, gypsum + postassium sulfate, and gypsum + ammonium nitrate were evaluated for their influence on the development of peanut pod rot in field test plots at Tifton, GA, in 1983-1984. Pythium myriotylum, Rhizoctonia sp., and Fusarium sp. were isolated from decaying pods, and fungal propagules from the soil were enumerated during the season. The involvement of these fungi in the disease was inconclusive. Peanut (Early Bunch) treated with gypsum tended to be higher in yield, lower in pod rot, and higher in percent sound mature kernels (%SMK) regardless of the accompanying treatment. Gypsum tended to ameliorate the harmful effects of potassium sulfate, magnesium sulfate, or ammonium nitrate by reducing concentrations of magnesium and nitrogen in the fruit compared with those found in peanuts treated with magnesium sulfate, potassium sulfate, or ammonium nitrate. Calcium in the fruit was negatively correlated (P = 0.01) with nitrogen, phosphorus, potassium, magnesium, other minor elements, and pod rot at harvest and was positively correlated with %SMK and yield. Evidence is presented for the hypothesis that the peanut pod rot complex is initiated by the same conditions that cause blossom-end rot of fruits.