Topics in Subtropics

There are numerous species of ants present in citrus orchards, however, the most common are the Argentine ant (southern and coastal California), the native gray ant (San Joaquin Valley) and the southern fire ant (statewide).

Various insects, birds, and other animals pollinate plants. Bees, especially honey bees, are the most vital for pollinating food crops. Many California crops rely on bees to pollinate their flowers and ensure a good yield of seeds, fruit, and nuts.

Biological control of Phytophthora cinnamomi in avocadothrough the use of mulches was identified by an Australian grower and later described as the "Ashburner Method" by Broadbent and Baker. The technique uses large amounts of organic matter as a mulch along with a source of calcium.

A call from a small grower, surprised at the sudden decline of the avocado trees. It must be a disease was the grower's thought. Well driving up to the site, there were numerous trees with canopies indicating drought stress. In fact most of the trees looked like they had had the water turned off.

At a recent meeting the question came up about the fate of nitrogen fertilizer applied through the irrigation system.