The field experiments were conducted during three kharif seasons 2012, 2013 and 2014 to study the effect of meteorological parameters on brown leaf spot of rice under different transplanting dates, methods and plant population. The experiment was laid out in split-split plot design with two transplanting dates (15th June and 30th June) in main plots, three methods of planting (conventional, SRI and furrow) in sub plots and two plant population (625 and 300 plants per m2) in sub-sub plots with three replications. The brown leaf spot incidence was recorded at weekly interval from the start of its incidence. The incidence of disease (percentage) was higher under conventional planting (58.6 %) followed by SRI (52.3 %) than furrow planting (49.9 %). The disease incidence was 5 per cent higher in high plant population (625 plants m-2) as compared to lower plant population (300 plants m-2) mainly due 4.1 per cent higher relative humidity within canopy. The correlation analysis revealed that minimum temperature and evening relative humidity significantly affected the disease incidence. The regression model developed with 2012 and 2013 data had highly significant R2 values which was validated with 2014 data.

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Wheat crop is attacked by number of diseases some of which cause yield losses and deteriorates quality. Rust pathogens are most important pathogens of wheat which can cause considerable economic losses if uncontrolled. Stripe rust, caused by Puccinia striiformis f. sp. tritici, is an important wheat disease common in wheat growing areas experiencing cold and humid weather conditions during the crop season. Different meteorological parameters influence occurrence and development of stripe rust in northern India including Punjab. Based on investigations on relationship of stripe rust with weather parameters, weather based prediction model for stripe rust was developed using disease severity and weather data (2007-08 to 2018-19) recorded at Ludhiana. The data of 2009-10 and 2019-20 was used for validation of model. Regression model based on maximum and minimum temperature, morning relative humidity and sunshine hours gave good results. Validation of model indicated that relationship between observed values of disease and predicted values was very close.

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:The field experiments were conducted at Research Farm, School of Climate Change and Agricultural Meteorology during 2012-13 and 2013-14. This study was planned to know importance of row orientation in radiation interception and growth dynamics of wheat crop. Three wheat varieties viz., HD 2967, PBW 550 and PBW 343 were sown under two row orientation i.e. North-South (N-S) and East-West (E-W) on 25 th November during both crop seasons. PAR interception, dry matter accumulation and leaf area index were recorded at periodic intervals during both crop seasons. The PAR interception was more in east-west row orientation as compared to north-south row orientation in all the three varieties. Among different varieties, HD 2967 intercepted maximum photosynthetically active radiation due to highest leaf area index of crop. Relationships were developed between PAR interception and dry matter accumulation and leaf area index. Highly significant co-efficient of determination (R 2 ) were found and these R 2 -values indicated that PAR interception significantly influence dry matter accumulation as well as leaf area index of crop.