In Saskatchewan, sites in the Brown and Dark Brown soil areas are usually included in Zone 2. The Zone 1 area of adaptation is usually the Black, Moist Black and Grey soil zones. In Zone 2 areas, tolerance to heat and drought become more important, and late maturity is not necessarily a penalty. Disease is also a consideration for choice of pea varieties. Mycosphaerella blight and powdery mildew.
Mycosphaerella blight is more problematic in cool and wet environments.
If the disease starts to develop in the lower canopy in June, the disease can reach the destructive phase in July. Lower stem infection leads to excessive lodging, stem rot and yield reduction. From the standpoint of variety resistance, no discussion is necessary because none of the varieties have good tolerance to the disease. The best ratings on the scale are fair, which really doesn t amount to much. Powdery mildew is an unusual disease because it is favored by dry conditions.