| Popis: |
Botrytis blight caused by Botrytis gladiolorum is the most devastating disease under North Indian conditions. The development and spread of this disease is favoured by cool and moist weather conditions generally prevailing in the months of February and March under Punjab conditions. The spatial and temporal dynamics of any disease provide valuable information on development of disease epidemics. The current experiments were planned to measure spatial and temporal development of Botrytis blight in susceptible (Sancerre) and resistant varieties (Nova Lux and Jacksonville Gold) of gladiolus under natural field conditions. It was observed that there was an increase in spread of the disease with time in both the susceptible and resistant varieties. The spread of disease in the varieties Sancerre, Jacksonville Gold and Nova Lux, varied from -500 to 425, -375 to 200 and -400 to 250 cm in East-West direction and -450 to 500, -125 to 300 and -150 to 300 cm in North-South direction from the infection focus on X and Y axis, respectively, during 2011-12. The disease spread was more during 2012-13. The disease intensity and its lateral spread from the foci of infection were higher in the susceptible variety than the resistant. Agrometeorological data on wind direction revealed that the progression of disease was more towards the southeastern direction due to flowing of northwesterly winds during January-March, during both the crop seasons, i.e. 2011-12 and 2012-13. |
