Potato and tomato blight is a disease caused by a fungus-like organism which spreads rapidly in the foliage and tubers or fruit of potatoes and tomatoes in wet weather, causing collapse and decay. Once you have it, it is pretty much game over for the infected plant, so how do we limit its effect.....
If any plot has blight infections, these plants must be removed and either burnt or taken home immediately to try to reduce the impact on neighbouring plots growing crops, failure to do so will mean the infected crops will be removed for you and you may be stopped from growing that crop next year!
What to Look for:
You may see the following symptoms:
- The initial symptom of blight on potatoes is a rapidly spreading, watery rot of leaves which soon collapse, shrivel and turn brown. During humid conditions, a fine white fungal growth may be seen around the edge of the lesions on the underside of the leaves
- Brown lesions may develop on the stems
- If allowed to spread unchecked, the disease will reach the tubers. Affected tubers 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.
- Early attacks of blight may not be visible on tubers, but any infected tubers will rot in store
- The symptoms on tomato leaves and stems are similar to those on potatoes
- Brown patches may appear on green fruit, while more mature fruits will decay rapidly
Once you have Blight on your potatoes and tomatoes there is really nothing you can do but remove the infected plants immediately to try to reduce the risk of the disease spreading, it is mandatory to remove the debris from site or burn it if the wind is blowing the right way, NEVER compost the debris as Blight can last up to 4 years in a dormant phase so increase the risk of infection in following years.