Gray leaf spot warning
July 3, 2006
The warm, humid weather conditions that support gray leaf spot (Pyricularia grisea) development are bubbling away in many locations. In California, we diagnosed our first case of gray leaf spot last week, on ryegrass roughs. The timing of the disease coincided well with the predictions from Dr. Frank Wong's gray leaf spot model.
If you are considering treating for gray leaf spot, remember that rotation among different products (see below) is essential, as gray leaf spot is at high risk…