Effect of weather parameters on dieback disease severity of Kinnow mandarin (Citrus reticulata) in Haryana, India

Aim: To assess the dieback disease severity in Kinnow mandarin (Citrus reticulata Blanco) and to understand the role of weather variables on dieback. Methodology: Disease severity was recorded in the fixed orchards of the five randomly selected plants. The scoring was done on the infected twigs and branches per plant. AUDPC was determined based on the data recorded on different days. Correlation was performed to find out the effect of different weather factors on the severity of dieback. Results: The initial dieback disease symptoms were observed in the 11th SMW, which reached at peak (20.73%) in the 27th SMW. The studies revealed a strong positive correlation between minimum temperature and dieback severity and a moderate positive correlation with the maximum temperature (“r”=0.846, p<0.01 & 0.571, p<0.05), while the wind speed showed a moderate positive correlation (“r”=0.599, p<0.01) with dieback severity. Further, multiple regression predicts dieback severity based on weather conditions, with minimum temperature (X2) showing a particularly strong influence and explaining 72 percent of disease severity variability. Interpretation: The information from this study can be utilized to provide protective advisory services to farmers and to develop integrated disease management strategies for the timely management of dieback disease. Key words: AUDPC, Citrus reticulata, Dieback disease, Kinnow mandarin, Weather factors