Incidence of sesame phyllody disease in relation to dates of sowing and meteorological parameters and its effect on sesame growth, yield and oil quality

The effects of dates of sesame sowing and meteorological parameters on sesame phyllody disease incidence were studied during summer and “kharif” seasons in 2017 in Assam, India. The effect of the disease on growth, yield and quality of sesame oil were also determined. The lowest disease incidence of 5.66% was observed in crops sown in the month of February and the highest disease incidence of 22.16% was observed in August sown crops. The leafhopper vector Hishimonus phycitis population was significantly and positively correlated with the disease incidence during both seasons. During summer season the temperature and relative humidity were positively correlated, while diurnal variation and sunshine hours were negatively correlated with disease incidence. During the “kharif” season, maximum temperature and diurnal variation were positively correlated while wind speed, total rainfall and number of rainy days were negatively correlated with the disease incidence. Considering various parameters the disease could be predicted up to 97% during summer season and up to 95% during the “kharif” season. The disease adversely affected the growth and yield attributes of sesame, reduced the oil content and deteriorated the oil quality.