The Citrus Pest Management Guidelines have been updated —
Significant changes to the management recommendations for Asian citrus psyllid, Fuller rose beetle, Diaprepes root weevil and bean thrips were made:
- Author: Tunyalee Martin
- Contributor: Elizabeth Grafton-Cardwell
It’s 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.
If you plan to apply a pesticide, use the Department of Pesticide Regulation’s VOC calculators to determine emissions from fumigant and nonfumigant pesticides. You can get to the calculation site by going to the UC IPM Pest Management Guidelines: Citrus, click on a pest link and scroll down to the treatments. Click on the Air Quality button at the top of the treatment table.
Simple steps can minimize the release of VOCs into the air:
- Use pesticides only when necessary.
- Decrease the amount of pesticide applied if appropriate.
- Choose low-emission management methods.
- Avoid emulsifiable concentrate (EC) formulations and fumigants.
Ozone, or smog, is caused by mixing VOCs, nitrogen oxide, and sunshine. High levels of ozone can harm people and crops. Regions in California that do not meet federal or state air quality standards for ozone, called nonattainment areas, may restrict the use of pesticides that release VOCs.
Brigade WSB insecticide applied to skirt-pruned citrus trees is very important for preventing Fuller rose beetles from climbing the trunks and laying eggs on the fruit. FMC updated their 2ee trunk treatment recommendation to improve the explanation of how to properly apply the chemical to the trunk. Using the least amount of water possible provides more concentrated and longer lasting protection. However, concentration needs to be balanced with sprayability and avoiding contact with fruit. http://www.fmccrop.com/grower/Products/Labels-MSDS.aspx
A meeting was held in Visalia on June 17 on the subject of protecting citrus fruit against egg-laying by Fuller rose beetle. Fuller rose beetle is extremely difficult to kill- the adults are built like tanks, live forever, and can go weeks without feeding. Foliar applications of Sevin, Actara and Kryocide work the best to kill adults, but no insecticide treatment kills all of them. The larvae are underground so they are difficult to treat. The eggs have a thick outer shell that protects them from insecticides and they are tucked under the button of the fruit. Because foliar insecticides are not very effective, the best line of defense against the pest is preventing it from ever reaching the trees. To accomplish this, a two step approach is the best strategy. First, skirt prune the trees up at least 24" so the branches don't touch the ground. This forces the flightless beetles to climb the trunk to get to the leaves. The next step is to block them from climbing the trunk by applying Brigade WSB in a thick band around the trunk. (See our web site for more details on how to build a spray wand to treat tree trunks http://ucanr.edu/sites/KACCitrusEntomology/Home/Fuller_Rose_Beetle_384/Management_36/) The Brigade repels the beetles and if they cross it, paralyzes them. The best treatment is the 0.5 lb AI/acre rate. The current 2ee allows only one treatment of this rate. CCQC hopes to obtain a 24c special registration, in the near future, that allows two treatments of this rate. The Brigade lasts 12-16 weeks and so a treatment applied in June and one in September will protect the trees from more than 90% of the beetle emergence. Foliar treatments could also be applied to provide a further level of protection. Research is underway to study the efficacy of these methods and to develop a post harvest treatments to replace Methyl Bromide fumigation, which is no longer allowed in Korea.
The second male flight has started in Kern and Tulare counties. It occurs 1100 degree days after the biofix of the first male flight. Temperature units are ahead of the 30 year average. See our web site for more information.