My pear trees have light yellowish leaves with black outer edges. I live in the Mojave desert and this is the second year they have been like this. They are about 4 years old and the soil is very alkalai. Would sulphur phosate help or just more fruit treee fertilizer? I sprayed a dormat oil this late January. Thanks Russ

Reply to post by Russ, on May 31, 2002 at 13:10:21:

It sounds like you already know you have an alkalinity problem. Have you had the soil tested thoroughly?
It also sounds like your tree may have not only pH-induced chlorosis, but possibly leaf scorch, caused by heat and water stress.
The link I've added talks a bit about these things. Lowering pH and reducing heat and water stress may help a lot. Do you have a salinity problem as well? Frequent, shallow irrigation can exacerbate that problem.