Effective management of Asian citrus psyllid in Florida citrus using low volume horticultural oil

Low volume (LV) aerial and ground sprays have become an important method of application in Florida citrus. During Feb 2011, we started a trial in a 10.9 acre plot of 'Valencia' orange in Lee County. We compared LV spray of 435 HMO with the Grower Standard (GS) and an Untreated

Check (UC) in a 3x3 Latin square design.  A Proptec rotary atomizer P400D spray machine was used for all treatments. HMO was applied every 2 weeks at 2 gpa.  During May 2011, significantly fewer psyllids were seen on GS trees compared with HMO trees, but during June these differences disappeared.  Between Aug – Oct 2011, mean adult psyllid population numbers were lowest for GS, followed by Oil and UC.  Thus, LV oil treatments suppressed ACP, although not as effectively as the GS.  During winter 2011, HMO treatments suppressed ACP as effectively as GS.  The 2nd harvest (27 Feb 2012) showed HMO treatment with greatest lb solids followed by UC and GS.  Thus, LV application of 435 horticultural mineral oil (HMO) for control of ACP has shown promising results for the last 2 years.