The, in vitro, study showed that Vitavax Captan completely inhibited the growth of S. rolfsii at very low concentration (5 ppm), but R. solani required 100 ppm of the chemical for its complete inhibition. In case of Fusarium oxysporum, 500 ppm of Vitavax Captan were required for the complete inhibition of the fungus. Concerning Topsin M70, Fusarium oxysporum was sensitive to Topsin M70 where 100 ppm of the fungicide completely inhibited the fungus. Rhizoctonia solani could tolerate high doses of the chemical and was completely inhibited by the addition of 1000 ppm of the fungicide. Sclerotium rolfsii tolerated very high concentrations of the fungicide and the highest dose used in the investigation (10.000 ppm) did not cause complete inhibition. For both fungicides, it was found that the higher the concentration of the fungicide the greater the inhibition of the fungal growth. This was observed with all investigated fungi. Fungicides application decreased the fungal counts in sterilized soil infested with R. solani. S. rolfsii or both of them. This was observed in cultivated and uncultivated soils. The higher the dose of the fungicide the more reduction in fungal counts. The seed dressing of cotton var. Giza 70 with fungicides increased the percentages of germination and survival plants and decreased the damping-off percentages as compared to their respective control. Vitavax Captan was more effective against S. rolfsii and Topsin M70 was more effective against F. oxysporum f.sp. vasinfectum. |
