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Weather influences the production and productivity of various crops. If farmers aware about           the real time weather factors such as temperature, relative humidity, wind speed, wind           direction and rainfall it will be the effective to prevent the crop failure and achieve high yield with better economic returns. The right weather information at right time facilitates the farmers to plan agricultural operations from selection of crops to post harvest to avoid crop losses. 382 AAS bulletins were prepared and disseminated to the farmers during 2019-2020. To study the            effect of weather based agro-advisory services, a random sample survey was conducted from 60 farmers from villages of Tiruvallur and Tiruttani block of Tiruvallur district. Results indicated that focusing illiterate farmers are much more important and dissemination of weather advisories in audio or visual format is preferable to make them to adapt weather based agricultural practices. The survey revealed that 65 per cent of farmers check weather forecast before going for spraying operation, 73 per cent for irrigation and 55 per cent for animal husbandry maintenance. Our study revealed that the farmers focus more on spraying and irrigation operation based on weather forecast. Further, awareness is to be created to realize that they should also need to follow weather forecasts from the selection of crop to post harvest in order to achieve better productivity and good income.

The nature of gene action governing important quantitative traits viz.yield and drought tolerance in rice were studied through six parameter model of generation means analysis using six generations (viz., P1, P2, F1, F2, BC1 and BC2) of five crosses by imposing drought stress at reproductive stage. Additive gene action was noticed for the traits like days to flowering, panicle length, 100 grain weight and root thickness in majority of the crosses while the yield characters like productive tillers / plant, filled grains / panicle, harvest index and grain yield / plant and the drought tolerant characters like spikelet fertility, root length and root / shoot ratio were governed by dominance gene action. Both additive and dominance effects were found in panicle length in the cross Kallurundaikar / Moroberekan; spikelet fertility, dry root weight, root/shoot ratio and grain yield / plant in the cross Norungan / Moroberekan and 100 grain weight and root thickness in the cross PMK 2 / Moroberekan. Interaction effects mainly of additive x additive was noticed in panicle length, filled grains /panicle, dry root weight and root/shoot ratio in most of the crosses while dominance x dominance gene action was predominant in 100 grain weight and both additive x dominance and dominance x dominance in days to flowering and plant height.

The effectiveness and efficiency of gamma rays and EMS in relation to chlorophyll mutations were studied in two varieties of sesame (Sesamum indicum L.) viz. SVPR 1 and CO1 in M, generation. Four types of chlorophyll mutants namely xantha, chlorina, striata and Xantha viridis were observed. Xantha viridis was observed in maximum proportion followed by chlorina and striata in both the varieties. Gamma rays was found to be more efficient and effective than EMS in both the varieties. The effectiveness and efficiency of both the mutagens was more in SVPR1 than CO 1.

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