Potato blight is a disease caused by a fungus like organism that spreads rapidly in the foliage and in potato tubers in wet humid weather, causing collapse & decay. The initial symptom of blight on potatoes is a rapidly spreading, watery rot of leaves, that shrivel & turn brown, also causing brown lesions on the stems. If allowed to spread unchecked, the disease will reach the tubers, affected tubers will have a reddish brown decay below the skin, firm at first but soon developing into a soft rot as the tissues are invaded by bacteria. Blight is airborne & travels at rapid speeds.
Keep a close eye on your potatoe patch for any signs of blight, and remove any infected leaves as you see them. Obviously the more diligent you are in this respect the longer you can prevent the spread of the disease. Removing infected leaves is particularly successful if the weather turns dry after doing it. If over 10 % of the foliage is affected cut of all the growth at soil level, this should prevent the tubers in the ground from infection. infected foliage should be removed or burned. There is no chemical spray on the market to prevent the disease but these good hygiene tips could help
- Always buy your seed potatoes from a reputable supplier
- If watering is required apply to the base of the plant
- Blight spores on foliage are washed down through the soil & will infect tubers, earthing up potatoes can reduce levels of infection.
- Crop rotation
Blog & Research by Mark Burton (Allotment Secretary)
