Lemon Tree in Orange

Question from Debbie:

Hello, we have a lemon tree which is about 5-8 years old and I keep finding lemons on the ground which have a large brown softish spot on the end. What is this from and what should I do?

Answer from Pat:

Brown rot on citrus is caused by a Phytophthera fungus. It usually strikes in wet or foggy weather but can also happen when fruit trees are growing in too much shade or when sprinklers regularly hit the foliage. When fruit falls onto the ground and remains there, it rots and thus infects the ground with the fungus which lives in the ground and gets splashed up onto the tree. Good garden hygiene usually controls it easily.

First correct the sprinkler situation if that has been a factor. Next pick up all the fruit that has fallen onto the ground and keep it picked up weekly. Also look over the tree and make sure no mummified remains of fruit or fruit with brown rot on them remains hanging on the tree. If you find more, cut them off and send all damaged fruit to the dump, don’t put into the compost. Finally, get a yardstick and cut off all the foliage that is hanging lower than 24 inches from the ground. Home gardeners who keep up these good practices usually get the problem under control without spraying with poisons.