A model for Tilletia indica (Karnal bunt)-Triticum aestivum (Wheat) system under changing environmental conditions

Karnal bunt (KB) of wheat incited by Tilletia indica Mitra is now gaining importance from the last few years due to its increasing incidence. Regular surveys are conducted to collect wheat grains samples from different grain markets of Punjab, India. Since weather plays a significant role in the initiation as well as the development of Karnal bunt. Thus, the variation in Karnal bunt incidence worked out and is being interpreted in relation to the prevailing environmental conditions during the most susceptible stage for the two decades (1991-92 to 2014-15) for the Punjab, India. The incidence of Karnal bunt was correlated with the weather parameters during the February and March of the corresponding year. The correlation analysis revealed the positive role of rainfall, rainy days, evening relative humidity, and Humid thermal index of March and the negative role of sunshine hours of February in the development and incidence of Karnal bunt. By using these parameters, a multiple regression model was developed and validated for forecasting the disease. The regression analysis showed a coefficient of determination of 0.77 and a D.W value of 1.88. The detailed analysis of historical data for more than two decades divulged the amount of total rainfall as well as the number of rainy days of March as the most critical factor for the Karnal bunt development.

The online version contains supplementary material available at 10.1007/s42360-022-00520-w.