Prospects of biorationals to control Maruca vitrata (geyer) in pigeonpea and yield-infestation relationship

Maruca vitrata is an important pest of pigeonpea and other legumes in India. A number of biorationals have shown good promise against the pest. The present study was conducted to evaluate the potential of ecofriendly products like Dipel (Bt), Neemoil 3%, Metarhizium anisopliae 2x10⁸ CFU/ml, Beauveria bassiana 1x10⁹CFU/ml, Spinosad 45% SC in comparison with Chlorpyriphos 20EC to manage the spotted borer, when applied as foliar sprays. Pooled data of two years revealed that Bt and Spinosad were highly effective recording least pod damage (5.1%), least seed damage (4.3–4.5%), highest yield (1235–1237 kgha⁻¹) and most profitable benefit: cost ratio (3.2). Neem oil and Metarhizi um fared next better. B. Bassiana and Chlorpyriphos though were better than the control, were inferior to the other treatments. Correlation and regression studies on the extent of pod and seed damage on yield indicated that pod damage and seed damage were significantly but negatively correlated with yield. Regression equation was fitted and discussed.