Question
whitegrapefruit 1
Hi Kathy, I wrote you the following question and you asked for some photos;
I'm in Southern Cal. I have several citrus trees. Orange, tangelo, tangerine, white grapefruit and red grapefruit. My tangelo and both grapefruit trees all have a white fungus on them. It is on the tops of some of the fruit which is not ripe yet. The fruit with the fungus is dying. Also, ants are all over the infected fruit. All three trees also have areas that are dying, no leaves or fruit and branches are dry and brittle.
I really hope you can help me. Since I last saw the trees last week it has spread and it looks to be spreading to my orange tree. These trees are actually my bosses who asked me to look after them.
AnswerHi Jeff, thanks for the photo, this is what I think it is and you could check further. I have never seen it on any of my fruit trees, but you could check it out further on the web. It is called greasy spot and the pics look like what you have on your citrus and can be cured from what I have read.. kathy
Greasy spot is controlled effectively with
copper fungicides or oil provided spray timing
is correct and the placement of the material
is on the underside of the leaf. A single application
should be made in June or July. Because
of the superficial growth of the fungus on the
surface of the leaf and the long period of time
(2-3 weeks) for deep penetration by the fungus
into the leaf, the single application not only protects
the leaf from future infections but also kills
the superficial fungus growth already present.
It is therefore unnecessary to apply the spray
before the first spores are likely to reach the leaf
as is the case with most other fungal diseases.
