Biochemical constituents in okra cultivars affect the infestation of shoot and fruit borer, Earias vitella F.

The study was conducted to find out the effects of the biochemical constituents of shoot and fruit of six okra cultivars on the infestation of the shoot and fruit borer Earias vitella (Lepidoptera: Noctuidae). The infested shoots and fruits of the tested cultivars, namely JK-635, JK-045, IPSA Dheros, BARI Dheros-1, Parboni Kranti and Arka Anamika were recorded, and infestation rate was evaluated based on the moisture, chlorophyll, free sugar, total sugar, and protein contents of the plants. The leaf chlorophyll was the highest in Arka Anamika cultivar (total 2.92 mg/g fresh weight of leaf). Arka Anamika also had the highest amount of moisture, free sugar, total sugar and protein (92.38, 0.49, 0.91, 17.82 and 15.89%, respectively) in the shoot at the vegetative stage of the crop and revealed the highest shoot infestation (15.89%). The infestation of the insect on okra shoot, and marketable matured fruit showed significant positive correlation by the borer with moisture, free sugar, total sugar and protein contents. Furthermore, the amount of these biochemical constituents of marketable matured fruits also was the highest (moisture: 93.18%, free sugar: 2.18%, total sugar: 3.16% and protein: 20.25%) in Arka Anamika. On the contrary the shoot and marketable fruit of the cultivars JK-635 and JK-045 showed the lowest level of biochemical contents and revealed the least infestation by shoot and fruit borer.