No abstract

Drought is the most severe abiotic stresses in many parts of the world and is one of the major problems in present-day climatic scenario. Drought tolerant varieties are with high demand which seems to be a great challenging task to plant breeders however difficulties are combined by the difficulty of crop yield on the genetic and physiological bases. Drought resistance may be defined as the mechanism(s) causing minimum loss of the yield in a drought environment relative to the maximum yield in a constant-free of optimal environment for the crop. Several researchers explained the plant reaction to drought through drought escape, dehydration avoidance, and/or dehydration tolerance mechanisms. Drought stress decreases size of the leaves, stem extension and root proliferation inside the soil, it also disturbs plant water relations and reduces water-use efficiency ultimately reduces the yielding ability of the plant so, breeding for Drought resistance is a good approach, following different breeding strategies and approaches to develop a drought resistant variety combining both conventional and molecular approaches. Considering the parameters like root morphology studies, proline estimation, leaf rolling etc., Selection based on a comprehensive approach of testing might be more effective in breeding better drought-tolerant cultivars.

Against the increasing vulnerability of agriculture and farm livelihoods to climate change, the study attempted to analyse the trend in climate variables and their impact on major crop yields during the period from 1966-2011, across 4 agro-climatic zones forming Gangetic Plains Region. A rising trend was observed in annual and seasonal (kharif and rabi) mean maximum and minimum temperature across the zones. Rainfall on the other hand, showed a declining trend. Overall, climate change adversely impacted crop yield, but the magnitudes of such effects vary spatially. The results reveal that rice and wheat yield will decline in the entire Gangetic region. By 2050s, maize yield will be higher by 6 percent in Lower Gangetic Plains; pearl millet will increase by 15 percent and rapeseed & mustard by 3.8 percent in Trans-Gangetic Plains. Amongst the crops, sugarcane yield was the most impacted to climate change and is expected to reduce by 21 percent in Middle Gangetic Plains towards end of the century. Hence, there is a need to formulate sustainable adaptation measures and practices suitable to location-specific needs for enhancing climate resiliency and capacity of agricultural system to withstand climatic shocks.

Characterization of heavy metals in 5 Km2 range of dumping yard in relation to soil, water and crop has been studied. The concentration of Cd (4.05 mg/kg) in soil was higher than the permissible limit of WHO (3 mg/kg) and in descending order of metals in soil was found to be Fe> Cr>Cd>Ni>Zn>Cu>Pb and in bore well water it was Cr, Fe, Pb, Cd, Zn and Cu (23.20, 0.63, 0.31, 1.19 and 0.69 mg/l respectively) than the permissible limit (0.54, 0.40, 0.068, 0.03, 0.22, 0.018 mg/l) and their respective concentration ordered as Fe>Zn>Cu>Pb>Cd>Ni>Cr. Further the vegetables grown nearby dumping yard was highly contaminated by Cr in range (2.78 to 12.78 mgkg-1) in tomato, beans and cabbage and even in ragi and green gram Cr was high (1.78 to 14.96 mgkg-1). i.e., in Tomato; Cd>Fe>Cr>Zn>Pb>Ni>Cu, Beans; Cr>Cd>Pb>Fe>Zn>Cu>Ni, Cabbage; Cr>Cd>Pb>Fe>Zn>Cu>Ni, Ragi; Fe and Zn were below permissible limit and Pb, Ni, Cu, Cd are BDL and Green gram; Cr>Fe>Zn>Pb>Cu > Ni>Cd. In support of results, primary survey was conducted in nearby 20 villages circumventing the dumping yard. A total of 150 respondents were randomly enquired to know their level of knowledge and health status as result of open dumping site. The results revealed that 43.33%, 36% and 20.67% as medium, high and low impact in relation to heath and knowledge aspect of dumping site. Thus there is a considerable impact on environment and humans due to the presence of heavy metal in crop, soil and water.