Understandably, organic growers are concerned about the Asian Citrus Psyllid (ACP), a pest that is a carrier of a devastating disease of citrus trees, huanglongbing (HLB). ACP findings are particularly concerning for organic producers because of how few choices there are for organic control methods. In cases of CDFA eradication efforts, there are no currently accepted organic treatments, but organic producers do have tools for management and prevention.
We encourage citrus growers to read up on the issue and be proactive with preventive management. In general, organic common sense principles apply to managing this pest as well as all other pests. Providing habitat so that birds, bats, and generalist insect predators can live in the orchard is always important and should not be underestimated as a long-term approach. Proper balanced nutrition and irrigation of trees to minimize stress is important because stressed plants are more attractive to pests. Careful monitoring through trapping, observation, and staying in touch with regional experts is key to staying ahead of the pest.
The CDFA web page devoted to ACP has lots of useful information about the pest lifecycle, a response plan for Tulare County, maps of finds, and links to Integrated Pest Management (IPM) information and sites. One helpful resource is "Integrated Pest Management Analysis of the Alternative Treatment Methods to Eradicate the Asian Citrus Psyllid," which is important reading for organic producers. Some of the methods mentioned in the paper are valid approaches for organic growers to use to make their orchards inhospitable to the ACP. Some methods, such as cultural controls (which address the nutritional balance in the tree) or planting insectary plants to encourage beneficial organisms and predators of the ACP, are not covered because of the aim towards eradication rather than control. Other techniques, such as biological control through microorganisms or parasites, are very promising for the future but are still undergoing research and not available to commercial growers. These beneficial organisms would be for long-term control but not for eradication.
There is substantial research underway on organic treatment options by UC Cooperative extension and others. The current recommendation for organic growers is to spray a low rate of oil on trees at 14-day intervals. Pyganic has been tested on ACP and works as a contact pesticide for adults, but it is too short-lived to be an effective eradication material without a prohibited synergist added to keep it from degrading quickly. The contact knocks down the adults while the systemic can get to the eggs and nymphs. Growers in Florida use Pyganic and oils to keep the pest in control in a non-eradication situation. In California, Pyganic carries the risk of exploding populations of Citrus Red Scale when used frequently. We encourage growers to refer to the University of California Agriculture and Natural Resources (UC ANR) website for detailed information. Please do not apply any control materials prior to CCOF approval.
CCOF will continue to provide timely information on alternative strategies for our members. We will also push for CDFA-accepted organic treatment options, and continue communicating to CDFA and the research community about the importance of organic treatment options, and impacts of CDFA eradication efforts on organic producers.