White rust is the major disease of spinach in Texas.
White, blister-like pustules form on the lower side of the leaf. In advanced stages, the white lesions form on the upper side of the leaf. Generally, the upper surface will only be chlorotic. Plants infected with the white rust fungus are weak and collapse quickly if environmental conditions are favorable for disease development. Initial outbreaks each season follow source event such as hard rains that deposit soil and oospores on the young plants.