Peanut Pod Rot Complex: A Geocarposphere Nutrient Imbalance. A. S. Csinos, Department of Plant Pathology, University of Georgia, Coastal Plain Experiment Station, Tifton 31793. T. P. Gaines, Department of Agronomy, University of Georgia, Coastal Plain Experiment Station, Tifton 31793. Plant Dis. 70:525-529. Accepted for publication 31 December 1985. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-525.

Gypsum (CaSO₄ · 2H₂O), magnesium sulfate (MgSO₄), potassium sulfate (K₂SO₄), ammonium nitrate (NH₄NO₃), and gypsum + magnesium sulfite, gypsum + potassium 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.