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 | |
|---|---|
|
CURRENT FLOWER BUD INDUCTION ADVISORY #5 for 2011-2012-02/28/12
This is a service to our citrus growers posted on the CREC website. The internet Expert System on intensity and time of bloom was recently moved to a different server and can be accessed anytime: http://disc.ifas.ufl.edu/bloom
Current Status: 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 were between February 1 and 17. On trees observed in Central Florida very few flowers were produced from this wave and currently not more than a few fruit of about ½ inch diameter are on the trees from this wave of flowers.
After another 170 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 was February 20th to 31st. This is perhaps the heaviest of the three waves of flower buds on trees with three waves of initiated flower bud growth. In Central Florida these are in or near full bloom and may be a little behind the original predicted date for full bloom.
Finally, a third wave of flowering was 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 peak about March 10th to 14th according to the original Flowering Monitor System prediction. The model has moved the full bloom date up, but I don’t see it on the trees. On some trees this third wave is nearly equal in intensity to the second.
Ft. Pierce and Umatilla have continued to behave differently than other citrus locations according to the model. Each location had only two waves of flower buds growing with Umatilla being earlier and Ft. Pierce later. The model now predicts a third cohort of flower buds growing in Ft. Pierce with a full bloom date later in April but I don’t think buds are still available for that wave.
In Central Florida, tree to tree bloom intensity is highly variable and stage of development is also, with stressed (declining) trees blooming earlier as usual. HLB and citrus blight appear to be the primary reasons for the declining trees.
Overall, my assessment is that we have a moderate bloom. It is divided between two cohorts of flower buds which are 2 to 3 weeks apart in stage of growth depending on the location. It remains to be seen what kind of fruit set we will get from these two sets of flowers. The second drop wave should be over with in all areas except the Indian River by the end of May, at which time set can be evaluated. I don’t plan to make another evaluation until early June.
If you have any questions, please contact me (albrigo@ufl.edu).
