Dhaliwal, L.K. DhaliwalDharampal2021-07-302021-07-302020Dharampal (2020).Effect of defoliation and row direction on microclimate and diseases in raya (Brassica juncea) (Unpublished M.Sc. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.https://krishikosh.egranth.ac.in/handle/1/5810171154The research experiment entitled “Effect of defoliation and row direction on microclimate and diseases in raya” was conducted at Research Farm, Department of Climate Change and Agricultural Meteorology, Punjab Agricultural University, Ludhiana during rabi 2019-20. The experiment was conducted with two varieties (PBR 91 and PBR 357), two row direction (North-South and East-West) and three defoliation treatments (1st defoliation, 2nd defoliation and control means no defoliation) in factorial-split plot design with four replications. The Package of Practices as recommended by PAU was followed for raising the crop. The PAR intercepted was higher in variety PBR 357 as compared to PBR 91 due to higher leaf area index. Maximum PAR interception was recorded under North–South direction compared as to East–West direction. In defoliation treatments, PAR interception was maximum in the defoliated plots than control. High relative humidity was observed in E-W direction as compared to N-S direction. Among the modification treatments the first defoliation (at flowering stage) proved very effective against the alternaria blight as well as white rust. The disease severity was low under defoliation treatments than control. Alternaria blight severity was higher in E-W row direction and lower in N-S direction. Similarly white rust severity was higher in E-W row direction and lower in N-S direction. Variety PBR 91 showed higher area under disease progress curve (AUDPC) as compared variety PBR 357 for alternaria blight and white rust. Among different defoliation treatments, the area under disease progress curve (AUDPC) was maximum in control treatment followed by 2nd defoliation and 1st defoliation. Seed yield was more (20.4 q/ha) in N-S direction compared to E-W direction (18.2 q/ha). Variety PBR 357 variety gave higher (19.7 q/ha) yield than PBR 91 (18.9 q/ha). Under the modification treatment defoliated crop (Defoliation 1) recorded the higher yield (20.2 q/ha) than control (18.4 q/ha).EnglishThesis