Seasonal incidence of major insect pests infesting brinjal (Solanum melongena) crop in Udaipur, India

Abstract

A field trial was conducted to find out the seasonal incidence of major insects pests of brinjal during August to December at Horticulture Farm, Rajasthan College of Agriculture, Udaipur. The investigation revealed that the incidence ofjassid (Amrasca biguttula biguttula Ishida) and white fly (Bemisia tabaci Gennadius) commenced after third week of August. The population of jassids touched the peak (15.87 jassids per 5 plants) during 1st-7th October at 28.25°C mean temperature and 65.65% relative humidity, whereas whiteflies reached the peak level during the 24th-30th September (34.76 white flies per 5 plants) with 25.55°C temperature and 65.20% relative humidity. The minimum population ofjassids and white flies were observed during the beginning of December (1.54 jassids per 5 plants) with 20.50°C temperature and 50.25% relative humidity and third week of August (1.43 white flies per 5 plats) at 26.45°C temperature and 73.8 relative humidity, respectively; whereas the incidence of brinjal shoot and fruit borer (Leucinodes orbonalis Guenee) appeared last week of September with 8.34% infestation on fruits at 25.55°C mean temperature and 65.20% relative humidity and incidence reached the maximum level (67.45%) during the last week of October with 24.4°C temperature and 48.25% relative humidity. The population of jassids and shoot and fruit borer was found non-significant negatively correlated with average relative humidity but jassids population positively correlated with temperature, whereas whiteflies population showed a positive significant correlation with relative humidity but non significantly negative correlation with temperature.