Physiological Leaf Spot is showing up in Southern Alberta
Physiological Leaf Spot is suspected in a number of winter wheat fields in Southern Alberta.
Physiological leaf spot (PLS) appears as round or oval lesions that may be yellow or bleached white to gray in color. Lesions may also have a dark center with a narrow chlorotic (yellow) halos and tend to be more numerous toward the tip of the leaf blade. PLS lesions are often found in the upper canopy, and missing or rare on lower leaves.
Three Factors Favoring Physiological Leaf Spot (PLS):