Topics in Subtropics

Its that time of year when citrus and avocado growers need to collect leaf samples for nutrient analysis to guide fertilizer applications. Leaves are collected between August 15 and October 15 and sent to the lab for analysis.

(This article summarizes California Department of Pesticide Regulations online VOC information.) Its that time of year again when hot weather fuels the creation of ground-level ozone, also called smog. High levels of ozone can harm people and crops.

UCCE Farm Advisor Gary Bender finally has his 14 chapter book on avocado history, botany and cultural practices on the San Diego County web site. Check it out: http://ucanr.

Training At planting (preferably in spring), if trees have an unbranched trunk greater than 2 feet tall, the tree should be headed back. This procedure should induce other buds along the trunk to shoot. Always remove leaves at positions where new shoots are required.

Iron chlorosis is an off duck. Soil is basically iron with some aluminum, silicon and oxygen added in for good measure, but plants can lack for iron because it is not available to be taken up.