Relationship between sorghum ergot, sowing dates, and climatic variables in Morelos, Mexico

Abstract

The importance of sowing dates to the development of sorghum ergot (Claviceps africana) was determined at Tlayca, Morelos, Mexico during the rainy seasons of 1998-2000. Annual variation in ergot incidence occurred, with the highest levels in the year 2000. Sowing dates between June 15 and July 14 had the lowest levels of ergot incidence and severity. Temperatures below 15°C 3 weeks before flowering increased ergot incidence. The optimal weather factors for ergot development were a mean day temperature of 25°C, a maximum relative humidity of 96%, a maximum temperature of 28°C, and nighttime relative humidity of 86%. © 2002 Elsevier Science Ltd. All rights reserved.