1Agri. Res. Station, Maharana Pratap University of Agri. & Tech., Ummedganj, Kota, (Rajasthan).
2AICPIP, Central Potato Research Instutute, Shimla-171 001, (Himachal Pradesh).
The effect of planting dates and weather factors was studied in relation to development of potato stem necrosis disease (caused by a tospovirus) starting from the autumn/winter seasons of 1994–95 at Kota (Rajasthan). The crop had the maximum disease incidence (DI) and index (DX) when planted early in the beginning of October and decreased gradually thereafter. The decline in DI was particularly sharp from end of October. Such an increase in DI and DX was strongly correlated (r = >.9) with higher weekly mean temperatures (above 25°C) which prevailed up to the end of October. The increase in yield with the delay in planting may be due to decrease in disease incidence and optimal weather suitable for bulking of the crop.
