EPIDEMIOLOGY AND MANAGEMENT OF POWDERY MILDEW OF OKRA CAUSED BY Erysiphe cichoracearum DC.
| dc.contributor.advisor | Y. S. AMARESH | |
| dc.contributor.author | ASHWINI R | |
| dc.date.accessioned | 2023-12-29T13:45:52Z | |
| dc.date.available | 2023-12-29T13:45:52Z | |
| dc.date.issued | 2023-12-29 | |
| dc.description.abstract | Okra powdery mildew caused by Erysiphe cichoracearum DC. is a destructive disease causing potential yield loss. Survey conducted during Rabi 2019-20 and Rabi 2020-21, revealed that, mean disease severity was maximum in Ballari (60.59, 56.00 %) and least in Yadgir (40.81, 37.18 %) districts. Out of 17 crop plants tested, powdery mildew symptoms were developed on five cultivated crops viz., cucumber, ridge gourd, black gram, green gram, cowpea. Spore germination of E. cichoracearum was maximum in 1.5 per cent glucose solution (84.64 %) at 24 hours of incubation. Highest conidial germination (58.12 %) was observed at 25 0C and (56.32 %) at 85 per cent relative humidity. The correlation study revealed that, during Rabi 2019-20, maximum ‘r’ value (0.157) was recorded one week after initial infection and maximum (528.15) AUDPC value recorded on 49th SMW. Whereas, during Rabi 2020-21, maximum ‘r’ value (0.155) was recorded at two weeks after initial infection and maximum AUDPC value (514.50) recorded on 49th SMW. The auto regression studies lead to equation for Rabi 2019-20, Y = 7.9 + 0.86X with R = 0.91 while Rabi 2020-21 Y = 7.579 + 0.849X with R = 0.902. Out of 50 genotypes screened, one genotype i.e., EC329404 showed moderately resistance reaction. Comparatively low disease index (9.08 %) with increased yield (96.59 q ha-1) recorded in plots received with three sprays of difenconazole (0.1 %). In in vitro evaluation, among the systemic fungicides, difenconazole (86.06 %), among the contact fungicides, wettable sulphur (78.68 %), among the combi fungicides, tebuconazole 50 % + trifloxystrobin 25 % (88.06 %) resulted in maximum inhibition (88.06 %). Among bio agents evaluated, mean maximum inhibition observed with P. fluorescence (Pf-1) (64.20 %). Field evaluation of fungicides during Rabi 2019-20 and Rabi 2020-21 revealed that, three sprays of tebuconazole 50% + trifloxystrobin 25% recorded maximum disease reduction of 91.81, 89.91 per cent over untreated control and yield up to 110.54, 108.18 q ha-1. | |
| dc.identifier.uri | https://krishikosh.egranth.ac.in/handle/1/5810204991 | |
| dc.language.iso | English | |
| dc.pages | 291 | |
| dc.research.problem | EPIDEMIOLOGY AND MANAGEMENT OF POWDERY MILDEW OF OKRA CAUSED BY Erysiphe cichoracearum DC. | |
| dc.sub | Plant Pathology | |
| dc.theme | EPIDEMIOLOGY AND MANAGEMENT OF POWDERY MILDEW OF OKRA CAUSED BY Erysiphe cichoracearum DC. | |
| dc.these.type | Ph.D | |
| dc.title | EPIDEMIOLOGY AND MANAGEMENT OF POWDERY MILDEW OF OKRA CAUSED BY Erysiphe cichoracearum DC. | |
| dc.type | Thesis |