1Indian Agricultural Research Institute, Regional Station, Agriculture College Estate, Pune-411005, Maharashtra.
2Division of Agricultural Economics, College of Agriculture, Pune-411005, Maharashtra.
Citrus tristeza virus is the main component of citrus decline syndrome observed among citrus orchards throughout Maharashtra state, India. Transmission of virus occurs through vegetative propagation and different species of aphids. The period of aphid colonization on new shoots of citrus plants was weather specific in this region. Monitoring of aphid population by colour traps in the Kagzilime plantation during 2001–03 at Pune showed highest weekly population of 2684.69 aphids/trap in January when maximum and minimum temperatures were 29.61°C. and 1l.28°C, respectively, with average relative humidity of 63.19 percent whereas lowest weekly population of 3.46 aphids/trap was observed in May having maximum and minimum temperatures of 37.26°C. and 23.42°C, respectively, with average relative humidity of 49.62 percent. Two peaks of population build-up of aphids were observed during July and January throughout the year. Temperature played important role in population buildup of aphids whereas relative humidity showed least effect on number of aphids collected in traps placed at different heights. Minimum temperature during 2001 and maximum temperature during 2002 expressed significant effect in checking aphid population. As the height of traps increased, the correlation of aphid population with minimum temperature showed decreasing trend.
