Blight - Total Loss of all Fruit
by Jelle Ferwerda
Unfortunately, this is more a tip to look out for when growing tomatoes, and avoid loosing all your crop to late blight. The big killer of tomato and potato crop.
Blight is a fungus that affects tomato plants when relative air humidity is high. Typically a disease to sprout up during cold rainy spells, it may also occur when it is warm, but only with very high humidity. Once an infection occurs, a complete loss of crop for that plant is imminent. So when you recognize the infection, one should completely remove the infected plant in order to avoid further infection.
However, one can help in avoiding blight on your plants: Ensure that a lot of air can circulate around the plants: Once fruit-ripening starts, remove large parts of the lower foliage. This will help the top-soil to dry out and wind may blow the moisture away, reducing humidity.
Also, leave plenty of space between plants, again to assist wind moving between plants. Later in summer, one should consider making a small cover over the tomato plants, thus reducing the amount of water on leaves, and therefore reducing humidity around the living matter.