Kumawat,G.L.B.R, Rachanashree2024-04-272024-04-272022https://krishikosh.egranth.ac.in/handle/1/5810208430Fenugreek (Trigonella foenum-graecum L.) is one of the important and oldest spice and medicinal crops and is cultivated throughout India. It is attacked by many diseases, however, powdery mildew incited by Erysiphe polygoni DC. is a major constraint in cultivation of fenugreek. Powdery mildew disease appeared during the end of January and persisted till the maturity of the crop. Symptoms were observed as white floury patches on leaves, tendrils, stem and pods whereas cleistothecia appeared late in the season seen as black specks immersed in mycelial mat. Microscopic observation revealed that conidia were barrel in shape and formed singly and in chains. Conidiophores were septate that were straight to sub-straight with 4 to 5 cells. Thirty six genotypes and varieties were screened under natural condition to find out the source of resistance against the disease. It was found that HM 444 and UM 411 showed resistant reaction with percent disease intensity (PDI) of 9.66 and 10.27 respectively. The remaining nine were rated as moderately resistant, thirteen as moderately susceptible and twelve as susceptible.Biochemical studies on thirty six genotypes and varieties were undertaken twice, once before the disease occurrence and then after the disease occurrence. It was found that total phenol, peroxidase (PO) and polyphenol oxidase (PPO) content in plants increased in all the genotypes after the disease appearance and the amount of these components were higher in resistant ones and comparatively lower in susceptible ones. Chlorophyll content of all the lines decreased after the disease appearance and was greater in resistant lines than susceptible lines. Correlation between biochemical components and percent disease intensity was worked out. Phenol showed negative significant correlation (- 0.958) (-0.864) in both healthy and infected leaves with PDI, the enzyme peroxidase showed negative significant correlation (-0.929) (-0.847) in both healthy and infected leaves with PDI, the enzyme PPO showed negative significant correlation (-0.892) (-0.837) in both healthy and infected leaves with PDI and chlorophyll also showed negative significant correlation (-0.758) (-0.892) with PDI. Six treatments were evaluated along with one untreated control in three replications. Among them, two sprays of panchgavya 5% recorded minimum percent disease intensity of 30.66 with yield 13.47 q/ha. Field evaluation of six systemic acquired resistance elicitors with one unsprayed control in three replications were undertaken. The crop was sprayed at 45 days after sowing and it was found that salicylic acid 200 ppm resulted in minimum percent disease intensity of 21.18 and yield of 16.07 q/ha. Six fungicides with one treatment of water spray and untreated control in three replications were carried out twice where hexaconazole 5% SC at 0.1% recorded minimum percent disease intensity of 11.63 and with higher yield of 20.65 q/ha. ICBR for fungicides were calculated and hexaconazole showed maximum ratio of 1: 37.91EnglishThesis