Seasonal Incidence and Effect of Physical Plant Characters and Micro-climatic Conditions on Population of Wheat Aphid, Rhopalosiphum padi

The field experiment was carried out at the Agronomy farm, College of Agriculture, Pune, Maharashtra during Rabi season of 2023–24 to study the seasonal incidence of wheat aphid and effect of physical plant characters and micro-climatic conditions on aphid population. 10 plants from the plot were selected randomly and wheat aphid were recorded on weekly intervals. Wheat aphid was noticed in 3^rd week of December 2023 (1.20 aphids/plant). Thereafter, population of wheat aphid showed increasing trend up to 2^nd week of February 2024 (150.40 aphids/plant). Population of wheat aphid decreased thereafter till last week of December 2024 (9.70 aphids/plant) and disappeared during 1^st week of March 2024. Wheat aphid showed significantly positive correlation with bright sunshine hrs and negative correlation with minimum temperature. Whereas, significant positive correlations were observed between aphid population and number of tillers, plant height and stem thickness. Soil moisture also showed significant positive correlations. However, length of leaf blade, soil temperature at depth of 5 cm and 10 cm showed a nonsignificant relation with the aphid infestation.