|I have one yellow and one pink grapefruit tree and they have black soot on the leaves, the fruit has a white sticky mold on them, and there are brown bugs that look like weavils on the back side of the leaves. How can I treat my trees? Thanks
|Answer from NGA
September 24, 2010
|Sounds like your citrus trees have a population of scale insects. When these pests feed they excrete a sticky substance called honeydew. As the honeydew ages it turns black and is called sooty mold. To get rid of the honeydew and the sooty mold, you'll need to control the scale insects. Horticultural oil is effective in suffocating the insects. It can be phytotoxic to the leaves if sprayed when the weather is hot so wait until January and then apply the horticultural oil. Look in the fruit tree spray section of your garden department and you'll find lots of different brands available. Be sure that citrus trees and scale insects are both listed on the label. If so, the product is safe to use on your trees. Be sure to apply according to label directions.
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