I was hoping someone here might know what is wrong with my orange trees or has perhaps had a similar experience. Lately much the foliage has been turning fairly yellowish, and the young new growth has been turning yellow also and many of these new leaves are dropping off. The older leaves remain on the trees, but much of this years new growth is defoliated, and in some cases the twigs are already beginning to die back.

I have checked for pests, and I havent noticed anything like scale, aphids, or any of the usual suspects. Nothing is eating the new leaves and buds, they are simply turning yellow and dropping off. The trees have been in the ground about 3 years now, and have grown to about7-8 ft and done really nicely in past years.

Soil test indicated ph of 7.4-7.5, and I have fertilised this spring with ironite as well as a good 8-4-8 with micronutrients, which was recommended to provide extra iron and manganese and help stop the yellowing of the foliage. The trees have a 6-7 ft area which extends to the drip line that is free of grass or mulch, and the top layer of soil is allowed to dry out between waterings. The grapefruit and tangerine trees in the front yard recieve the same care and water, but neither of these have shown any signs of yellowing. Their new growth has been normal looking, and the older leaves are a glossy darker green. I'm at a loss here, as the orange trees in the back yard recive the same care and water and sunlight as the citrus in the front yard, and yet seem to be going downhill rapidly. Any good advice would be appreciated. Dave