I have a tangerine tree in my yard that is about 20 foot tall and is a very good producing tree. I have noticed that some of the leaves now have a black coating on them and there seems to be a lot of spider webs on the tree. what can I use to take care of this problem. I love this tree and don't know anything about caring for it except to water and fertilize when do my lawn. and when to pick the fruit. It has always had a bumper crop even tho most of the fruit is on the smaller side , this is due I think because of the amount of fruit on this tree Please help!!
You may be facing a number of pests. The webbing, along with stippled leaves, are usually indicators for the presence of spider mites. The black coating on the leaves is sooty mold which grows on honeydew excreted by a sap sucking pest such as scale and aphid. I believe horticultural oil is recommended for controlling these pests in an outdoor environment. An alternative is insecticidal soap.
Thank you for the quick reply. the next question I have is when should I apply the treatment you recommend. The blosson have set and the fruit is starting to be where blossoms were. Is now the time or should I wait.
Horticultural oil should be nontoxic, so you might as well apply it now. Sooty mold's a very common problem in Florida.
Much has been written on the use of horticultural oil in the citrus forum; you may want to review the postings. The recommendation is to apply the oil early in the morning or late in the afternoon. Ultra Fine and Volk are two oils mentioned.
