Studies on Insect Pest Dynamics of Cabbage and Management Strategies of Diamondback Moth, Plutella Xylostella (Linn.)

Abstract

The present investigation entitled ‘Studies on insect-pest dynamics of cabbage and management strategies of diamondback moth, Plutella xylostella (Linn.)’ was carried out on cabbage variety ‘Golden Acre’ during Rabi, 2021-22 and 2022-23. At Crop Research Centre, Sardar Vallabhbhai Patel University of Agriculture, Meerut (UP). The data were recorded on five randomly selected plants once in a standard week. The insect pest including natural enemies on cabbage, six orders (Lepidoptera, Hemiptera, Orthoptera, Coleoptera, Hymenoptera and Arachnida) were identified during field monitoring. Diamondback moth population reached up to maximum level of 9.67 and 9.33 larvae/five plant during 3rd week of January during Rabi 2021 and 4th week of January in Rabi 2022. The P. xylostella was active throughout the year with a varying degree of infestation. When the data of both the years were pooled all the treatments were found effective and significantly superior over untreated control. Spinosad 2.50% SC @600 ml/ha was the most effective insecticide against P. xylostella with (1.33 larvae per five plant) followed by Emamectin Benzoate 5% SG @200 g/ha, Diafenthiuron 50% WP 600 g/ha, Bacillus thuringiensis @1000 g/ha, Beauveria bassiana @1500 ml/ha, Metarhizium anisopiliae @2000 g/ha and Nimbecidine 0.03%@2500 ml/ha with 2.00, 2.67, 3.67, 4.50, 5.00 and 5.83 P. xylostella larvae per five plants respectively. Maximum diamondback moth larvae (8.00/five plant) were recorded in untreated control. All the treatments reduce the natural enemy’s population as compared to control. Among all the treatments, Nimbecidine 0.03%@2500 was found most safe with maximum pool mean number of C. septempunctata (3.33) and Spider (2.67) adult/five plant followed by Metarhizium anisopiliae followed by Beauveria bassiana, Bacillus thuringiensis, Diafenthiuron 50% WP, Emamectin Benzoate 5% SG and Spinosad 2.50% SC with (2.83, 2.33, 2.00, 1.17, 0.83 and 0.33 adult C. septempunctata per five plant and 2.33, 2.00, 1.50, 0.83, 0.33 and 0.17) adult spider per five plants respectively. All the chemical insecticides prove less safe to the natural enemies. Whereas maximum adult population of C. septempunctata and Spider was recorded from untreated control with (4.00 and 3.83 adult per five plant). When the data of both the year were pooled and found all the treatments were found again effective and significantly superior over untreated control. The highest incremental cost benefit ratio (ICBR) was recorded in Emamectin Benzoate 5% SG i.e., 1:10.57 which was comparatively superior over all treatments as sprayed on standing crop. The mean yield of cabbage was recorded from this treatment i.e., 176.67 q/ha and net profit obtained from the increased yield was 21033.33 Rs/ha., followed by Spinosad 2.50%SC 1:6.42 that produced mean yield of cabbage i.e., 186.33 q/ha, Diafenthiuron 50% WP, Beauveria bassiana, Metarhizium anisopiliae, Bacillus thuringiensis var. kurstaki, Nimbecidine 0.03% ICB ratio with 5.79, 6.21, 4.59, 2.56 and 1.77 respectively, mean yield with 173.50, 160.00, 158.50 and 156 q/ha. respectively. All treatments were superior over untreated control. The lowest cabbage yield 145.00 q/ha was observed in the untreated control.