Re: Green leaf discoloration

[David Bockman]

"Gofer" wrote in news: [e-mail]:

Dear members, > I live in Israel, in a penthouse, full of sunlight. I have many pots > with various plants: palm trees and citrus, seasonal flowers, like > penies and gotetia, and vines like passion frut. Some month or two > ago, just between the spring and the summer, many of my plants got > discoloration on the leaves: the smooth green leaves started to > yellow, but not in a smooth way, but rather in an inhomogeneous way. I > am attaching a photograph of a leaf. If you know what might cause the > change, and what is the cure, please help. Yours, > Y. Gofer > > > begin 666 leaf1small.JPG > > Attachment decoded: leaf1small.JPG > ` > end > >

Often this type of discoloration is indicitive of a sucking insect such as thrips or aphids. Look underneath the leaf for small black specks like pepper; if you see the specks, that is the insect's excrement.

[Suzy O]

I'd also check for spider mites. When there's a really bad infestation, you can see the fine webbing. Otherwise, as David Bockman said in a earlier post, check the underside of the leaves for tiny black specks -- this also can be a good indication of spider mites.

In any event, whether aphids or spider mites, an insecticical soap product should knock them out. Follow the label recommendations and be sure to treat the underside of the leaves.

Good luck, Suzy O, Zone 5, Wisconsin