Co-Authors:
ROTEM, J., Department of Plant Pathology, Agricultural Research Organization, Volcani Center, Bet Dagan, 50250, Israel
WENDT, U., University of Glessen, Tropeninstitut, Glessen, 6300, Germany
KRANZ, J., University of Glessen, Tropeninstitut, Glessen, 6300, Germany
Abstract:
Exposure of naturally infected or inoculated cotton plants (Gossypium hirsutum cv. Acala) to sunlight greatly increased the expression of Alternaria alternata symptoms. Exposure for 8 h was sufficient to produce the effect, which occurred in plants of different age and under a range of conditions of temperature and wetness. The latter included marginal but recurrent dew periods interrupted by dryness by day. The effect of sunlight was also evident in G. barbadense (cv. Pima). Symptomless infections were detected in apparently healthy tissue of inoculated plants and were more frequent in those not exposed to sunlight. It is postulated that sunlight triggers the development of symptomless infections into visible lesions. Copyright © 1988, Wiley Blackwell. All rights reserved