Studies on Host Plant Resistance of Maize Against Spotted Stem Borer, Chilo Partellus (Swinhoe)

Abstract

The present investigation entitled “Studies on host plant resistance of maize against spotted stem borer, Chilo partellus (Swinhoe)” was conducted during Kharif 2018 and 2019. The field experiments were conducted at Crop Research Centre (CRC) and laboratory experiments was conducted in College of Agriculture (Departments of Entomology and Soil Science) of Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut- 250110 (U.P.). The incidence of C. partellus larval population started from 2nd week of July (28th standard week - Kharif 2018 and 2019) and reached to a peak level in the month of August (31st standard week - Kharif 2018 and 32nd standard week - Kharif 2019) and disappeared from 3rd week of September (37th standard week - Kharif 2018 and 38th standard week - Kharif 2019). The correlation coefficient results indicated that the abiotic factors such as rainfall and sunshine hours had significantly positive and negative association with C. partellus larval population on maize during Kharif 2019, respectively, whereas C. partellus larval population did not established any relationship with remaining abiotic factors during Kharif 2018 and 2019. Among all the genotypes screened against C. partellus, Vivek Hybrid 9, Vivek Hybrid 25, Wasc, Vivek Hybrid 39, HQPM 4, HQPM 8, Vivek Hybrid 43 and HQPM 1 were classified either as least susceptible or moderately susceptible on the basis of leaf injury rating and stem tunnel length, with minimum (< 2) per cent of dead hearts and number of exit holes. Biophysical characters such as leaf trichomes, leaf epidermal silica bodies, stem lignified vascular bundles, leaf length, leaf width, number of leaves per plant, stem diameter, internodal length and number of nodes per plant showed significant and negative correlation with leaf injury rating, per cent dead hearts, stem tunnel length and number of exit holes, whereas plant height showed negatively significant correlation with stem tunnel length and non-significant correlation with leaf injury rating, per cent dead hearts and number of exit holes. Biochemical constituents such as sugars and chlorophyll showed positively significant correlation and proteins showed positively nonsignificant correlation with leaf injury rating, per cent dead hearts, stem tunnel length and number of exit holes, while phenols and tannins showed significant negative correlation with leaf injury rating, per cent dead hearts, stem tunnel length and number of exit holes. The studies on induced resistance revealed that the organically manured plots showed significant superiority in reducing infestation of C. partellus compared to plots treated with recommended dose of fertilizer. However, among all the treatments untreated check and standard check has recorded lowest infestation levels as compared to organically manured plots. The visual biophysical traits (leaf length, leaf width, number of leaves per plant, stem diameter, internodal length, number of nodes per plant and plant height) were superior in standard check, followed by neem cake and poultry manure treated plots. The plots received organic manures registered higher leaf trichomes, leaf epidermal silica bodies, stem lignified vascular bundles, phenols and tannins, and lower sugars, proteins and chlorophyll content index whereas those plots received recommended dose of fertilizers recorded the vice versa. The maximum yield was recorded in standard check, followed by neem cake and poultry manure treated plots.