There’s very little one can do to avoid blight in the first place, but if it suddenly strikes, the first task is to remain calm, don’t panic, and try the following suggestions!
As the name suggests, this fungal infection mostly affects spuds, but outdoor-grown tomatoes are also highly susceptible. The foliage shows the first telltale signs, with shrivelling leaves that are often damp to touch. A brownish rot then appears, whereupon the entire plant collapses.
Blight is particularly active in wet, humid conditions. The microscopic spores are easily transported via wind or water droplets, so there really is nothing you can do to prevent it, but it’s important to act quickly the moment it arrives.
Although blight will kill a plant, it is harmless to humans, so any crops may be safely eaten. For tomatoes; harvest any useable fruits, then dig up the plants entirely. For potatoes; cut off the foliage to ground level, but leave the potatoes in the soil for another fortnight, by which time they will have hardened their skins to allow for harvesting with minimal damage. A dry, breezy day is preferable for this task. Dig them up carefully and leave them resting on the soil for a few hours – as their surfaces dry, any adhering soil can be easily and gently removed. Potatoes with damaged skins should be used