Topics in Subtropics

A microirrigaiton workshop on use and maintainence of systems in Spanish is being held on three successive dates in San Luis Obispo, Ventura and Fallbrook. These are the same workshop held on July 23, 24 and 25 in the respective areas.

Its that time of year again when hot weather fuels the creation of ozone, or smog. Some pesticides emit volatile organic compounds (VOCs) that contribute to ozone formation. Using pesticides that release VOCs may be restricted in certain California locations between May 1 and October 31.

Branch and trunk canker on avocado was formerly attributed to Dothiorella gregaria, hence the name Dothiorella canker. So far Botryopshaeria dothidea (anamorph: Fusicoccum aesculi) is the only known species causing Dothiorella canker on avocado in California.

The polyphagus shot hole borer (PSHB) is an invasive beerle that forms a symbiosis with a new, as-yet-undescribed Fusarium sp., together causing Fusarium dieback on avocado and hother host plants in California and Israel.

Microirrigation (drip, microsprinkler, fan jet) applies water through small openings and can easily be prone to clogging. For this reason, filtration is used to avoid introducing sediments into the system and all fertilizers are injected before the filters to avoid their clogging the system.