Description: Symptoms of halo blight start as small watersoaked spots on leaves, which gradually turn dark brown. The spots remain small and become surrounded by a wide yellow-green halo. The spread and development of halo blight is favored by wet weather and plant injury from rain, hail, people or equipment. Halo blight develops best when temperatures are somewhat cool, in the low to mid 70’s. (Common bacterial blight and bacterial brown spot prefer warmer temperatures, in the 80-90°F range.)
Solution: Plant disease-free seed, rotate crops, burn infected plant tissues, and clean contaminated equipment. Avoid working with plants when they are wet, as bacteria are easily transmitted in films of water. To prevent infection, or reduce its spread, apply Soap-Shield® Fungicidal Soap at 7-10 day intervals. Following heavy rain, or when the amount of disease is increasing rapidly, apply every 7 days, or even more frequently, at the highest recommended rate.