Biophysical basis of resistance in soybean genotypes against defoliators
AR Sasane, SK Bhalkare, PK Rathod and DB Undirwade
The field trial was conducted at Research Farm of Department of Entomology, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola during the kharif season 2015-16. In the study twenty genotypes were evaluated for resistance against defoliators. The results revealed that the genotypes viz; AMS 9933, AMS 115, AMS MS 5-18, RVS 2001-18, MACS 1370, SL 979, AMS 104 and JS 2029 proved effective to combat the menace of defoliators, resulted into minimum per cent leaf damage. The correlation studies revealed that a biophysical character like leaf succulency was positively and significantly associated with per cent leaf damage by defoliators at 25 DAS (r = 0.877) and at 40 DAS (r = 0.743). The leaf area recorded at 25 DAS also has positive correlation with the per cent leaf damage (r = 0.451). While leaf thickness (r = -0.793, -0.789) and trichome density on the leaf surface (r = -0.821, -0.835) were significantly and negatively associated with leaf damage percentage at 25 and 40 DAS. Moreover, trichome density has significantly negative correlation with incidence of Spodoptera larvae (r = -0.459, -0.463) at 25 and 40DAS. Thus, these soybean genotypes could be used in resistance breeding programme.