Development of IPM module against major pests of black nightshade, Solanum nigrum L.

Abstract

Solanum nigrum is an important upcoming medicinal cum green leafy vegetable belonging to the family Solanaceae. Like other plants, medicinal plants too have to bear the devasting attack of injurious insect pests. Extensive monitoring and development of eco-friendly pest management practices are essential in the production of high quality, pesticide residue free produces. Field experiments were carried out in farmer's holdings at Coimbatore and Tirupur districts of Tamil Nadu during June 2012 to September 2012 to assess the efficacy of botanical pesticides against sucking pests and defoliators infesting Solanum nigrum. The results revealed that among the treatments, foliar application of profenophos at 2 mL L(-1) is found to be the best treatment for the management of sucking pests as well as defoliators and also recorded maximum leaf yield of 22.40 kg 12 m(-2) plot harvest(-1). Among the botanicals, azadirachtin 1 and 2% aqueous leaf extract of Andrographis paniculata recorded maximum reduction in pest population and also conserved more natural enemies. Another field experiment was carried out in a farmer's holdings at Edayarpalayam, Coimbatore district during November 2014 to April 2015 to develop an IPM module for the management of insect pests of S. nigrum. Results of the field experiment revealed that among the treatments, the IPM module comprising of designer seed treatment [Polymer (3 g) - carbendazim (2 g) - Gaucho (5 g) - Azospirillum (120 g) kg(-1) of seed] - cowpea as border crop - erecting yellow sticky traps at 12 ha(-1) - need based spraying of azadirachtin 10,000 ppm at 1 mL L(-1) recorded the lowest incidence of sucking pests viz., aphids (0.2 per three leaves plant(-1)), thrips (0.1 per three leaves plant(-1)) and whiteflies (0 per three leaves plant(-1)) at 25 days after sowing (DAS) and afforded protection up to 35 DAS, followed by farmer's practice (chemical control) as against the maximum population of 28.4 aphids per three leaves plant(-1), 3.8 thrips per three leaves plant(-1) and 4.7 whiteflies per three leaves plant(-1) in untreated control. At 35 DAS, maximum number of Menochilus sexmaculatus grubs was recorded in untreated control (6.1 plant(-1)) and in IPM plots (5.8 plant(-1)). Maximum harvestable leaf yield of 14.28 t ha(-1) was recorded in the IPM plot, followed by the farmer's practice (13.15 t ha(-1)), as against 5.25 t ha(-1) in the untreated control. Hence, the IPM module is adjudged as the best treatment in the management of insect pests of S. nigrum.