Influence of Differential Phosphorus Accumulation on Corn Stalk Rot1

Abstract

AbstractStalk rot of corn (Zea mays L.) is a disease complex that appear to be affected by the plant's mineral nutrition status. Two inbred limes differing in P accumulation, their Fl hybrid, and the resulting high and low Paccumulating populations reselected from the segregating generation of the Fl hybrid were grown in the field in 1976 and 1977 in order to determine the effect of differential P accumulation on several stalk rot parameters. Plants of each entry were inoculated with either Fusarium moniliforme Sheldon emend Synd. & Hans. or Gibberella zeae (Schw.) Petch using a toothpick on which the pathogen was growing. At 14, 28, and 42 days after inoculation, measurements of rotted internodal tissue were obtained. The largest amount of stalk rot occurred in the low Paccumulating population. The dry weights, crushing strengths, and rind thicknesses of noninoculated stalk sections of each entry were significantly higher in the high P‐accumulating population than in the low P‐accumulating population in both years. Greatest weight loss after incubation with either F. monilliforme or G. zeae in closed containers for 30 days occurred in the low Paccumulating population. The highest incidence of lodging occurred in low P‐accumulating populations. Differential P accumulation appears to influence lodging potentials of these populations mainly through its effect on stalk quality.