BINDU K., PANICKARBHARGAVKUMAR MANUBHAI, PADHIYAR2022-10-182022-10-182022-10-17https://krishikosh.egranth.ac.in/handle/1/5810189114The present exploration was undertaken to study the “Physio-chemical bases of resistance to pulse beetle (Callosobruchus maculatus Fabricius) in blackgram and it’s management’’ at Pulses Research Station, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar during 2021-22. Varietal susceptibility of twelve blackgram genotypes/varieties to C. maculatus was evaluated based on five parameters like egg laying, developmental period, adult emergence, growth index and seed infestation. The average number of eggs laid on different blackgram genotypes/varieties in free choice condition varied from 8.33 to 27.67 eggs per 100 seeds and significantly minimum (8.33) eggs was laid on SKNU 2005. Whereas, significantly highest (27.67) eggs were laid on SKNU 2107. While in no choice condition, significantly least (17.33) eggs were laid on SKNU 2005 and significantly maximum (96.33) number of eggs were laid on SKNU 2107. Further, significantly longest (40.33days) developmental period was recorded in SKNU 2007 while significantly shortest (32.67 days) was noticed in SKNU 2005. Adult emergence was significantly less (32.44%) in SKNU 2005. While it was maximum (65.78%) in SKNU 2107. A significantly higher (1.66) growth index was observed in genotype SKNU 2107 and was more susceptible to pulse beetle. While significantly less (0.97) growth index was recorded in SKNU 2002 and GU 1. Seed infestation was significantly minimum (5.67%) in SKNU 2005 and maximum in SKNU 2107 (63.33%). Based on seed infestation, the genotypes SKNU 1905 and SKNU 2005 were classified as highly resistant, genotypes/varieties SKNU 1716, SKNU 2109, SKNU 2002, SKNU 2105, GU 1 and T 9 as moderately resistant and SKNU 2007, SKNU 2108, SKNU 2103 and SKNU 2107 are susceptible. When the genotypes/varieties were ranked in order of their relative susceptibility using various growth parameters SKNU 2107 and SKNU 2103 were still found most preferred, while SKNU 2005 and SKNU 1905 were less preferred genotypes. The blackgram genotypes/varieties were also evaluated for physical parameters of seed viz., seed shape, seed colour, seed coat texture, seed length, width, length width ratio, seed weight to understand the physical bases of resistance. The average Abstract II seed length and width varied in the range of 4.50 to 5.86 mm and 3.40 to 3.95 mm, respectively. The length width ratio ranged from 1.23 to 1.66 and seed weight of 100 grains ranged from 3.51 to 6.07 grams. Among biochemical parameters viz., total soluble sugars, total phenols, total flavonoids, total free amino acid and total tannins content of blackgram genotypes/varieties showed significant influence on various growth parameters of pulse beetle. Proteins had non significant correlation, with all growth parameters. Genotypes SKNU 2107 and SKNU 2103 had significant higher amount of total soluble sugars and free amino acid with a significant positive relationship with adult emergence, seed damage and infestation, while genotypes SKNU 2005 and SKNU 1905 had significant higher amount of total phenol, total flavonoids and total tannins and had a significantly negative relationship with adult emergence, seed damage and infestation. Eleven different plant based oils were evaluated for their effect on seed damage, weight loss, germination percentage and feeding index caused by C. maculatus in blackgram. All the treatments showed a significant effect as compared to untreated control. However, amongst different oils, neem oil was found to be significant most effective against C. maculatus. None of the treatments had apparently reduced seed germination even after two months of storage. Hence, these botanicals can be used as safer grain protectant in alternatives to chemical insecticides for long term storage of blackgram seeds.EnglishThesis