Effect of harvesting operations on the incidence of fungal spores over a rice field

Abstract

The effect of harvesting operations on the incidence of 13 fungal spore types over a rice crop at Bhimavaram (16°32′ N and 81°32′ E), India, was studied. Air samples were obtained over the same field by operating Rotorods for an hour from 0800–0900 h on four occasions before, during and after harvesting. Spore concentrations, especially of Arthrobotrys, Cochliobolus miyabeanus, Drechslera and Ustilaginoidea virens, were greatly elevated on the day of harvesting compared to two days previously, when the crop was still standing. By contrast, spore concentrations of Cercospora were unaffected while Stachybotrys-type declined. Spore concentrations were markedly smaller next day when the harvested crop was left flat in the form of sheaves. A further decrease occurred after the sheaves were removed to leave only the stubbles. It is suggested that repeated exposure of farm workers to unusual heavy spore concentrations during harvesting may be of considerable risk to their health.