Authors : M. N. Bhajbhuje
Page Nos : 371-377
Description :
Abstract:
The leaf spot causing pathogenic organism of fungal origin reduce quality and productivity of crop plants. A hybrid variety of Jawar is susceptible to fungal attack causing leaf spot disease. The resistance to pathogen is induced in young seedlings with seed treatment of abiotic elicitors. The Jawar seedling raised from treated seeds with dilute solution of chemicals were inoculated by spraying foliage with conidial suspension of Helminthosporium turcicum Pass and assayed for number and size of lesions on leaves at different intervals. Most of the chemicals, when used to soak seeds, induce resistance to 14-days-old susceptible Jawar seedlings against inoculation with Helminthosporium turcicum The disease index was very significantly reduced as well as lesion expansion was inhibited in plants receiving chemical seed treatment. Resistance effect persisted at significant levels even in 28-days-old plants. In vitro studies on fungitoxicity of leaf diffusate of treated plants on spore germination of H. turcicum indicates that different treatments lead to the development of moderate to high level of fungitoxicity in young seedlings. Treated young seedlings developed higher fungitoxicity over controls. Fungitoxicity gradually declined with age of plant and disappeared in 28-days-old plants. Studies on direct effect of these treatments reveals that chlorides of mercury, copper, cadmium totally inhibited fungal spore germination while other compound had only mild to moderate inhibitory effect.
Keywords: Fungitoxicity, susceptible, abiotic elicitors, Helminthosporium turcicum, induced
