Blueberry Management
The table below lists suggested blueberry management items for December. Suggested management items for the entire calendar year are available in an EDIS publication, Calendar for Southern Highbush Blueberry Management in Florida (https://edis.ifas.u.edu/publication/HS1363). Specic disease, insect, and weed controls are listed in the 2024 Florida Blueberry IPM Guide (https://edis.ifas.u.edu/publication/HS380), as well as in subject-specic publications referenced below. Also, a list of all UF EDIS blueberry publications can be found at www.blueberrybreeding.com/blog, along with a summary description and link to each. Remember to take a look at the UF/IFAS Blueberry Growers Guide phone app (available in both English and Spanish) for eld scouting tools, as well as information on all of the UF southern highbush blueberry cultivars (https://tosto.re/blueberryuf).
Disease
Once bloom occurs, monitor for Botrytis ower blight during cool wet periods. If present, spray suggested fungicides in rotation. Applications of fungicides prior to a forecasted need for overhead irrigation as freeze protection can help reduce Botrytis severity on plants damaged by low temperature injury. See UF EDIS Publication PP198, Botrytis Blossom Blight of Southern Highbush Blueberry (https://edis.ifas.u.edu/publication/PP119). Anthracnose (ripe rot) infections can begin as early as bloom; consider preventative fungicide applications, and using the Blueberry Advisory System for notications of increased disease development risk (http://cloud.agroclimate.org/tools/bas/dashboard/disease), also available as an app.
Insect Pests
Continue to monitor for blueberry gall midge and spray suggested insecticides when adults are observed. If traps are not used, spray before oral and vegetative bud break, with a second spray approximately 7-10 days after the rst application, following label directions. See UF EDIS Publication ENY-2105, Management of the Blueberry Gall Midge on Southern Highbush Blueberries in Florida (https://edis.ifas.u.edu/publication/IN1414). Also scout for scales, southern red mites and at mites, ower thrips, and blueberry bud mites, and if observed use applicable control measures. See UF EDIS Publications ENY-1006, Mite Pests of Southern Highbush Blueberry in Florida (https://edis.ifas.u.edu/in1284) and HS1156, 2024 Florida Blueberry Integrated Pest Management Guide (https://edis.ifas.u.edu/publication/HS380) for detailed suggestions.
Weeds
Apply post-emergence herbicide if weeds are at densities that hinder bush growth.
Hydrogen Cyanamide
Consider applying hydrogen cyanamide (marketed as Dormex, and BudPro) in deciduous production systems, in particular those with weak or delayed leaf canopy development and heavy fruit loads. However, at higher concentrations it can cause oral bud injury and reductions in yield, especially in some cultivars that are more sensitive to hydrogen cyanamide, including ‘Jewel’, ‘Primadonna’, and ‘Colossus’. Growers should do test applications by cultivar on small sections to determine safe concentrations. In addition, application should be made before 20% of the oral buds are at or past stage 3 (separation of bud scales) and after sucient chilling has occurred to minimize oral bud damage. See further discussion in UF EDIS publication HS976, Reproductive Growth and Development of Blueberry (https://edis.ifas.u.edu/publication/HS220).
Freeze Protection
Monitor forecasted and actual temperatures and utilize freeze protection strategies as needed. See UF EDIS publication HS968, Protecting Blueberries from Freezes in Florida (https://edis.ifas.u.edu/publication/HS216).
Pruning
Dormant pruning can be performed to maintain appropriate plant structure and size. Removal of
approximately 25% of old canes should be done annually beginning when a plant is ve to six years old, to
promote the growth of new canes. Low branches, weak growth, and damaged wood can also be removed at
this time. See UF EDIS publication HS1359, Pruning Southern Highbush Blueberry in Florida
(https://edis.ifas.u.edu/publication/HS1359).
Managed Bees
Have honey bees (and bumble bees if applicable) delivered; should ideally be placed in the eld after 10%
bloom but before 20% bloom. On large farms, hives should be distributed throughout the farm to the
extent it still allows access to bee providers. Conrm health of colonies upon delivery; at least 8 frames per
hive should have adults, and at least 6 frames should have brood in the cells, with good activity into and out
of the hives and on the bushes. Consider adding additional honey bee or bumble bee hives if there is a
heavy, concentrated bloom across the farm, nearby competing crops or wild plants blooming at the same
time, or ongoing poor weather conditions (cold, windy, or overcast). See additional details in EDIS
Publication ENY-172, Pollination Best Practices in Southern Highbush Blueberry in Florida
(https://edis.ifas.u.edu/publication/IN1237).
This Month's Blog Post
Good Pollination Practices
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March 9, 2025 - UF PSREU, Citra, Fl
CONTACT US
Doug Phillips
Blueberry Extension Coordinator, UF/IFAS
