Powdery mildew growing concern in california tomato fields

摘要

During the 2007 and 2008 growing seasons, California tomato growers in the Central Valley experienced more problems with powdery mildew than they've had in years. "The powdery mildew seems to be more difficult to control, it moves faster and it produces more spores," said Brenna Aegerter, farm adviser of vegetable crops and plant pathology for the University of California Cooperative Extension in San Joaquin County in Stockton. While typical mildew looks white and floury, tomato powdery mildew is normally very hard to see. "You have to look under the side of the leaves with a little hands lens and squint under the microscope. But by the end of 2006, we were seeing tomato powdery mildew with the white powdery look that this type of powdery mildew doesn't usually take on," Aegerter said.