It is necessary to ascertain the quality of irrigation water at Anbil Dharmalingam Agricultural College and Research Institute farm in order to monitor the possible effects of the sodic irrigation water on the soil. Irrigation with sodic water enhances soil sodicity built up in soils of experimental farm which leads to adverse effects on soil physical, chemical and biological properties, not fitted for farming. In areas where ground water is sodic and where good quality surface water supplies are either inadequate or not available at all and the farmers are left with no option but to use sodic ground water for irrigation purposes, which pose grave risks for soil health and environment. The quality of sodic water can be improved by treating with gypsum. Due to gypsum dissolution calcium and sulphate ions come in soluble form in irrigation water. Research conducted at Anbil Dharmalingam Agricultural College and Research Institute Trichy for reclamation of sodic bore well water revealed that the sodic bore water samples collected from bore well 1 (AMP shed) having initial Residual Sodium Carbonate (RSC) of 8.0 meq /lit and bore well 6 (Boys hostel) having initial RSC of 6.2 meq /lit indicated the decrease in RSC upto - 0.6 meq / l and 1.2 meq / l respectively due to gypsum treatment with 0.1 per cent (12.50 tons/ha) and 0.35 per cent ( 43.75 tons /ha ) at the retention time of 1 hour to irrigate 1 ha paddy field throughout crop establishment stage. It was concluded that for lowest retention time higher doses of gypsum was required for sodic water reclamation. As we increased the retention time, the required gypsum quantity was also minimized as observed for bore well 1 (AMP shed 8 meq/l)) sodic water samples with gypsum dose of 0.15 per cent (18.75 tons /ha) with the retention time of 4 hours. These findings were very much helpful for the farmers of Manikandam block, Tiruchirappallii district having secondary sodicity built up in soils due to sodic water irrigation during summer.

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Twenty one mungbean (Vigna radiate L.Wilczek) genotype were evaluated for the estimation of genetic variability, heritability, genetic advance, correlation coefficient, and path coefficient analysis for yield and its component traits. A considerable amount of genetic variability was observed among all the genotypes for all the character under study. GCV and PCV were highest for number of primary branches per plant, followed by 100 seed weight and number of clusters per plant. High genetic advance coupled with high heritability were observed 100 seed weight followed by number of clusters per plant, plant height and number of primary branches per plant. Combined results of correlation coefficient and path analysis revealed that number of primary branches per plant, 100 seed weight, biological yield and harvest index are major component traits for the improvement of grain yield.

Mealybug Planococcus lilacinus Cockerell (Hemiptera: Pseudococcidae) damages Cocoa, Guava, Citrus, Cotton and other plant families. Besides causing direct loss to the plants they also reduce the market value of infested fruits. The extent of the damage may go up to 70 percent in a severe infestation. An Australian ladybird beetle, Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) introduced from Australia is a potential bio-control agent and is being utilized on many crops in Southern India. Mealybugs or scale insects constitute the natural food of certain ladybird beetles. The adult beetles as well as their larvae (grubs) seek the pests and feed voraciously on all stages. They often wipe out the entire pest colonies. The ladybird beetles are being used for suppression of mealy bugs in citrus, coffee, grapes, guava, ornamental and a variety of other crops. The feeding potential of different development stages of C. montrouzieri, a biological control agent against mealybugs, was investigated on P. lilacinus. Fourth instar grubs and adults of C. montrouzieri were the most voracious feeders of mealybug. The number of mealybug consumed by 1st, 2nd, 3rd and 4th instar larvae and adult beetles of C. montrouzieri was 20, 33.30, 37.50, 40 and 66.60 percent respectively. The results indicate that C. montrouzieri has the potential to be exploited as a bio-control agent. Inoculative releases of 4th instar larvae and adults may provide instant control of P. lilacinus. Field experiments should be conducted to determine the efficiency of the ladybird beetle on this mealybug.