Naveen Aggarwal ¹, Jawala Jindal ²

Affiliations
1 Biocontrol Section, Department of Entomology, Punjab Agricultural University, Ludhiana 141 004, Punjab, IN
2 Maize Section, Department of Plant Breeding & Genetics, Punjab Agricultural University, Ludhiana 141 004, Punjab, IN

Abstract

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.

Keywords

Chilo Partellus, Deltamethrin, Maize, Trichogramma Chilonis, Validation.

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Ashwinder K. Dhaliwal ¹, Jaspal Kaur ², D. S. Brar ³, Jawala Jindal ²

Affiliations
1 Department of Entomology, Punjab Agricultural University, Ludhiana – 141004, Punjab
2 Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana – 141004, Punjab, IN
3 Department of Entomology, Punjab Agricultural University, Ludhiana – 141004, Punjab, IN

Abstract

Eight different isolates of Beauveria bassiana Balsamo (Vuillemin) were evaluated for their efficacy or biocontrol potentiality against Chilo partellus (Swinhoe) under controlled conditions at Punjab Agricultural University, Ludhiana. The results of the present studies revealed that all the eight isolates irrespective of their original host were pathogenic to C. partellus. The virulence of the isolates was increased with increase in spore concentration. As compared to other isolates, the native isolate of B. bassiana, PAU Bb and Bb 4668 caused higher mean mortality of C. partellus (68.75 and 56.25 %) at the concentration of 1 × 10¹⁰ spores/ml. These isolates were 56.49 and 7.17 times more pathogenic than the commercially available isolate of B. bassiana. Under screen house conditions, the efficacy of B. bassiana isolates, against C. partellus was comparatively lower than Decis 2.8 EC deltamethrin. However, the application of B. bassiana resulted in lower incidence of C. partellus than infested control.

Keywords

Beauveria bassiana, Bioassay, biocontrol, Chilo partellus, Maize.

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