Post by murrayc on Jul 17, 2021 14:55:36 GMT
A number of us have been fearing the risk of blight in this warm, very humid summer. Last year we went without blight at all.This week it has arrived at America Lane, starting at the front near to the gate and spreading quickly up the site. My plants caught it a couple of days ago and today I have cut down all of my central crops: second earlies and main crop potatoes. Another bed planted with Sarpo Mira blight-resistant variety looks to be ok (with fingers heavily crossed).
For those new to growing or new to allotments, these are the main details:
- Blight is a fungus, borne mainly on the wind, though if not treated or haulms removed the spores may stay in the soil and risk infection in future years in newly-planted tubersPlants are vulnerable in periods of high temperatures and high humidity - 2 consecutive days of around 10 degrees min night-time and 90% humidity
Commercial growers can spray to protect their plants but it's not cost-effective for allotment holders and not particularly ethical - If you do have the blight then in the interests of your own potatoes, because it will rapidly feed down to the tuber and rot underground, and of your neighbours, then cut down the stems to just above ground level. Gather all the haulms (the stems and leaves of the plant) and take them off the site: burn them or send to green waste where they will be superheated to kill off the fungus. Don't compost them - that's precisely the conditions where the fungus will develop.
- There are an increasing range of blight-resistant varieties available - both potatoes and tomatoes, and its worth looking into these