VIEW ARTICLE

Disease Control and Pest Management

Effect of Dinitroaniline Herbicides on Plant Resistance to Soilborne Pathogens. A. Grinstein, Department of Plant Pathology and Microbiology, Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot, Israel; J. Katan(2), and Y. Eshel(3). (2)Department of Plant Pathology and Microbiology, Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot, Israel; (3)Department of Field and Vegetable Crops, Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot, Israel. Phytopathology 66:517-522. Accepted for publication 4 November 1975. DOI: 10.1094/Phyto-66-517.

Seeds were sown in noninfested soil with or without herbicide at 1 µg/g soil. After emergence, seedlings were either transplanted to Rhizoctonia solani-infested soil or inoculated with Fusarium or Verticillium dahliae. Generally, resistance to the diseases in herbicide-treated plants was increased. Trifluralin, nitralin, butralin, and dinitramine significantly increased resistance of eggplant, tomato, and pepper to R. solani; disease incidence was decreased by 30-90%. This increased resistance was dependent on inoculum and herbicide concentrations. Benefin and isopropalin did not affect plant resistance. Resistance of beans was not affected by trifluralin, nitralin, or butralin, but was significantly decreased by dinitramine in one case. Trifluralin increased resistance of cotton to R. solani in certain cases and decreased it in others. The herbicides did not affect resistance of corn and oats to R. solani. Resistance of eggplant and tomato to Fusarium and Verticillium diseases was greatly increased by trifluralin and nitralin, resulting in as much as a 97% reduction in disease. Increased resistance occurred in spite of phytotoxic effects of herbicides. Trifluralin was detected in the hypocotyls of treated eggplants and cotton at concentrations of 0.84 and 0.15 µg/g respectively. Growth of the pathogens in vitro was inhibited at concentrations much higher than those used in soil or found in tissues.