Heweidy,, M., Mahmoud, N., Morsy, K., Ismail, A. (2002). CHEMICAL MANAGEMENT OF SOYBEAN DOWNY MILDEW CAUSED BY PERONOSPORA MANSHURICA IN EGYPT. Journal of Plant Production, 27(7), 4699-4707. doi: 10.21608/jpp.2002.255612
M. A. Heweidy,; Nagwa M. A. Mahmoud; K. M. Morsy; A. I. Ismail. "CHEMICAL MANAGEMENT OF SOYBEAN DOWNY MILDEW CAUSED BY PERONOSPORA MANSHURICA IN EGYPT". Journal of Plant Production, 27, 7, 2002, 4699-4707. doi: 10.21608/jpp.2002.255612
Heweidy,, M., Mahmoud, N., Morsy, K., Ismail, A. (2002). 'CHEMICAL MANAGEMENT OF SOYBEAN DOWNY MILDEW CAUSED BY PERONOSPORA MANSHURICA IN EGYPT', Journal of Plant Production, 27(7), pp. 4699-4707. doi: 10.21608/jpp.2002.255612
Heweidy,, M., Mahmoud, N., Morsy, K., Ismail, A. CHEMICAL MANAGEMENT OF SOYBEAN DOWNY MILDEW CAUSED BY PERONOSPORA MANSHURICA IN EGYPT. Journal of Plant Production, 2002; 27(7): 4699-4707. doi: 10.21608/jpp.2002.255612
CHEMICAL MANAGEMENT OF SOYBEAN DOWNY MILDEW CAUSED BY PERONOSPORA MANSHURICA IN EGYPT
Plant Pathology Research Institute, Agricultural Research Center, Giza, Egypt
Abstract
Five soybean cultivars; Crawford, Clark, Giza 21, Giza 35 and Giza 82 were evaluated for the control of downy mildew infection under greenhouse and field conditions using three different fungicides. In vitro studies show that Sandofan M-8 and Ridomil plus were more effective against the spore germination and germtube length of Peronospora manshurica the causal pathogen. Complete inhibition of the spore germination and germtube was obtained at 100 ppm of Sandofan M-B, and 200 ppm for Ridomil plus and Dithan M 45. The fungicide application under greenhouse conditions, 2 days before or 2 days after inoculation by the pathogen spore suspension at the rate of 1x105 sporeslml was also studied. It was observed that, the cvs. Giza 35 and Giza B2 showed lower infection than the other tested cvs., however Crawford gave the highest infection. The fungicide Sandofan M-8 was the most effective on downy mildew followed by Ridomil plus and Dithan M 45 either two days before or after inoculation. Field studies at both Sakha and Itay EI-Baroud in the growing season 2000 gave as similar results as the greenhouse. The obtained results indicated that three sprays of Sandofan M-8 or Ridomil plus, at the recommended rate of each fungicide when the first disease symptoms appeared and.t 15 days intervals, gave low downy mildew infection and high seed yield when compared with the check plots.