Validation of Biocontrol Technology for Suppression of Chilo Partellus (swinhoe) on Kharif Maize in Punjab

The management of maize stem borer, Chilo partellus (Swinhoe) with Trichogramma chilonis @ 100,000 ha^-1) at 12 days after germination (DAG) was compared with farmer's practice of two sprays of deltamethrin (Decis 2.8 EC @ 200 ml ha^-1 at 15 and 30 DAG during kharif 2011 and 2012 at farmer's fields in Punjab. The mean leaf injury due to C. partellus at 20 DAG was 8.04 and 6.87% in biocontrol treatment and farmers practice, respectively. The dead heart incidence of 3.85 and 2.55% in these treatments was significantly lower than untreated control (12.10%). The biocontrol plots recovered 31.18% parasitism compared to farmers practice and untreated control (2.30 and 7.67%). The coccinellids and spiders counts were also higher in biocontrol plots. The grain yield was at par in biocontrol treatments (46.10 q ha^-1) and farmers practice (48.67 q ha^-1) while it was significantly lower in untreated control (37.13 q ha^-1). Similarly, the net returns to the farmer in biological control treatments (Rs. 10008) was comparable to the farmers practices (Rs. 12424). The release of T. chilonis effectively reduced the damage of C. partellus, increased the natural enemies in maize ecosystem and provided convincing monetary benefits to the farmer.