This fertilizer application method is very useful during the summer and has been used all year in some cases. Summer decline usually appears first on greens in low areas that are surrounded by trees on the east, south and west sides. Wind movement is usually restricted in these areas and results in hotter and more humid environments than on nearby open greens. Trees and undergrowth should be removed on the southwest side to improve air movement from predominant southwest winds during the summer. The surface temperature of greens with restricted air flow is usually higher than nearby open greens.
Diseases caused by fungi are often a problem on all types of bentgrass greens.
Bentgrass on sand mixtures often appears more succulent and more susceptible to brown patch and Pythium blight. A fertilization program with the lowest levels of nitrogen possible in the summer will help reduce the susceptibility to these diseases. These fungi apparently do not cause significant damage unless plants are weakened by some condition such as anaerobic soil conditions, localized dry spots, high soluble salts or environmental stresses. Correcting or avoiding these conditions will help to prevent damage from this disease in the summer decline complex. A preventive fungicide program is needed during hot and humid weather to help control brown patch and Pythium blight.