Finally got the test results back for the yellowing trees in the orchard. Good thing too, as many of the trees are starting to show signs of yellowing as well. It turns out that the trees have a good case of Peacock Spot, a fungus that attacks olive
trees. The soil, water, and leaf samples were all relatively normal, though some nutrient deficiencies need to be addressed. But pretty much all the samples had the fungus and need to be treated.
The best treatment for this fungus is copper sulfate, which gets sprayed onto the leaves and trunk. Fortunately, it is an organic treatment, so we will be able to use it. On the other hand, we need to buy a big sprayer so we can apply it easily throughout the orchard. We need to get a jump on this because the rains will only make it worse this winter. It is a good excuse to go the tractor store to see what attachments I might “need”.