Flower Bud Induction Overview and Advisory
NOTICE FOR CITRUS EXTENSION AGENTS & SPECIALISTS AND GROWER NEWSLETTERS
The following information has been developed as part of the Decision Information System for Citrus
L. Gene Albrigo, Horticulturist Emeritus
Citrus Research & Education Center, Lake Alfred, FL
| Archives of past Flower Bud Induction Advisories | |
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CURRENT FLOWER BUD INDUCTION ADVISORY #4 for 2011-2012-01/11/12
This is a service to our citrus growers posted on the CREC website. The internet Expert System on intensity and time of bloom can be accessed anytime: http://orb.at.ufl.edu/DISC/bloom
Current Status:Mother Nature has not been friendly, but the weather has lived up to a La Niña year. The Flowering Monitor Model indicates that a first wave of flower buds was initiated to grow between December 3rd and 12th depending on the location, earliest initiation was in mid-Florida. The inductive cool hours had reached 620 to 640 in southern areas and 650 to 800 in central and northern areas of Florida’s citrus industry. The full bloom dates for this first wave of flower buds is about February 7 to 17. After another 200 to 250 cool hours accumulated a second wave of flower buds was initiated to grow with accumulated hours of 830 to 1000 from South to North in the citrus belt. The projected full bloom dates for these buds is February 25th to 31st. Finally, a third wave of flowering is projected for Immokalee and the Central Florida area with growth initiated after 1000 to 1150 hours of cool inductive temperatures. The bloom from this flower bud initiation should be weak and peak about March 10th to 14th.
A computer model anomaly in all of this year’s flowering projections is the lack of a prediction of flower bud growth initiation in response to weather conditions in Ft. Pierce, where 750 hours of temperatures of 68 degrees F or lower have accumulated and warm weather periods have presumably occurred. The Flowering Monitor System does not show the initiation of any flower bud growth for this Indian River area. Induction levels are now adequate for all citrus areas, but the flowering will be very spread out from two or more bloom peaks.
In southern and central locations where irrigation was continued into December, many trees reportedly are now flushing with light flowering. I don’t see any extensive flowering in any of our nearby trees, but the occasional bud with popcorn flowers can be seen. A few terminal buds are swelling.
Some growers may still want to apply urea or phosphorous acid to boost flowering, but most bud development has probably already started and the value of these sprays now is questionable.
Remember that freezing temperatures can still occur until late January and frost damage is a slight possibility at bloom time, particularly since the first and second bloom waves will be earlier than normal.
To summarize our current status, we have 2 or 3 waves of flower buds now differentiating with full bloom predictions from mid-February to mid-March. The combination should provide an economic level of flowering but bloom should be very spread out making ideal timing of production practices difficult. The best procedure is probably to schedule for the largest bloom.
Growers that kept trees under drought stress in early December will probably avoid the early February bloom and should have a good bloom about the end of February. Now we can wait and see what really happens.
If you have any questions, please contact me (albrigo@ufl.edu)
