Bud Advisories Help Growers Time Psyllid Sprays

Tacy Callies Industry News Release


The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) is reminding citrus growers that flower bud advisories are now being issued. The UF/IFAS advisories can help growers determine when to spray for HLB-spreading Asian citrus psyllids and when to stop spraying in an effort to protect pollinating bees.

Tripti Vashisth, a UF/IFAS associate professor of horticultural sciences, will continue providing the advisories every other week through early spring. Growers can find the flower bud advisories on the UF/IFAS Citrus Research and Education Center (CREC) website.  

“This year is predicted to be an El Niño winter, which means more rain and possibly cooler temperatures,” said Vashisth. “All of this will affect flowering. So, we will have advisories every 15 days to provide accurate information on floral bud induction.”  

Flower bud advisories are driven by the Citrus Flowering Monitor web app, which predicts dates when citrus trees will bloom based on observed and predicted weather patterns and other parameters (variety, expected yield, tree age and soil type). Growers can enter parameters on their cell phones or computer that are specific to their groves to get a prediction. Knowing the bloom date is important for managing bloom and other related events. The Citrus Flowering Monitor also gives specific recommendations on how to manage flowering.   

Growers should keep track of induction hours in their areas and watch for projected warm periods from the weather services. Normal healthy trees could have their induction boosted by applying some drought stress. Unfortunately, with HLB making root systems vulnerable, growers shouldn’t risk heavier preharvest fruit drop by using water stress to prevent unwanted early vegetative growth and enhance induction of flowers.  

Based on weather predictions, growers concerned about early flowering can apply gibberellic acid (GA) to prevent some early flowering. There are many things to consider when using GA. See additional information here before using GA. 

Source: UF/IFAS