Seasonal incidence of fruit borer, Helicoverpa armigera and its eco-friendly management in tomato, Solanum lycopersicum

Abstract

A field experiment on seasonal incidence of Helicoverpa armigera and its management was carried out at the experimental farm, department of horticulture, Assam Agricultural University, Jorhat, during 2015-16 and 2016-17, respectively. The peak infestation of H. armigera (6.06 and 6.30 larvae per plant) was recorded during March in 2015-16 and 2016-17, respectively. The first incidence of H. armigera during 2015-16 was observed on 12th December’2015 with a mean population of 0.46 larvae per plant and larval population gradually increased till the harvest of the crop. The larvae attained maximum population of 6.06 larvae per plant on 22nd March’2016. During 2016-17, the first incidence of fruit borer was noticed on 17th January’2016 with a mean population of 0.9 larvae per plant and larval population gradually increased till the harvest of the crop. The larvae attained maximum population of 6.3 larvae per plant on 20th March’2017. All the treatments tested against fruit borer gave effective control and increased yield over untreated control. Spinosad @ 0.3 ml per litre was graded as most effective treatment in reducing fruit borer followed by Azadirachtin @ 5 ml per litre.