Relative Natural Resistance of Newly Introduced Populus deltoides Clones in India against Defoliator Clostera cupreata

As a preliminary and initial assessment, the relative natural resistance/susceptibility of 38 newly introduced Populus deltoides clones in India from 3 regions [Eastern Gulf (Mississippi, Alabama); East Central (Tennessee) and South Atlantic (North Carolina, South Carolina)] of U.S.A. was evaluated against its prime insect defoliator, Clostera cupreata. Evaluation was done on the basis of the differences in the percent leaf area consumed by the pest for the entire larval period on different clones which varied significantly (P<0.05).The ranking of clones for selection was done in the decreasing order of resistance with clones having lower values for the percent leaf area eaten lying at the 'resistant end' of the table and those having greater leaf area eaten lying at the other extreme (susceptible end) of this table. In general, clones from 'East Central' region showed a most resistant character than clones from 'Eastern Gulf' or 'South Atlantic' regions. Clones 14-15-6-1 (Mississippi); 21-14-4-5 (Mississippi); 14-15-6-5 (Mississippi); 38-30-3-3 (Tennessee); 11-11-15-5 (Mississippi); 14-15-6-3 (Mississippi) and 101-24- 1-3 (South Carolina) which were the most resistant clones amongst the 39 clones, were also found to be superior to test Clone G-48 (Texas) (the standard and most widely planted clone in Northern India) in terms of natural resistance and hence are promising candidate clones for future selection.