Disease
Once bloom occurs, monitor for Botrytis blossom blight during cool, wet periods. If present, spray recommended fungicides in rotation. Also consider beginning applications of fungicides to prevent anthracnose fruit rot. Use the Blueberry Advisory System (BAS), which is available at www.agroclimate.org/BAS, to know when weather conditions are favorable for the development of anthracnose fruit rot. See EDIS Publication PP366, Blueberry Advisory System: A Disease Alert System for Blueberry Anthracnose Fruit Rot (https://edis.ifas.ufl.edu/publication/PP366). 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 EDIS Publication PP198, Botrytis Blossom Blight of Southern Highbush Blueberry (http://edis.ifas.ufl.edu/pp119).
January—apply Ridomil to help prevent Phytophthora root rot. See EDIS Publication PP374, Phytophthora Root Rot on Southern Highbush Blueberry in Florida (https://edis.ifas.ufl.edu/publication/PP374) and HS1156, 2024 Florida Blueberry Integrated Pest Management Guide (http://edis.ifas.ufl.edu/hs380).
Insect Pests
Monitor for blueberry gall midge (BGM), and spray recommended insecticides when adults are observed. If traps are not used for monitoring, and the planting has a history of BGM infestation, spray insecticides before floral and vegetative bud break, with a second spray approximately 7–10 days after the first application, following label directions. See EDIS Publication ENY-2105, Management of theBlueberry Gall Midge on Southern Highbush Blueberry in Florida (https://edis.ifas.ufl.edu/publication/IN1414). Also scout for scales, southern red mites (Tetranychids) and flat mites or false spider mites (Tenuipalpids), flower thrips, and blueberry bud mites, and if observed use recommended control measures. See EDIS Publications ENY-2094, Wax Scale on Southern Highbush Blueberries in Florida (https://edis.ifas.ufl.edu/publication/IN1387) and ENY-1006, Mite Pests of Southern Highbush Blueberry in Florida (https://edis.ifas.ufl.edu/publication/IN1284). See EDIS Publication HS1156, 2024 Florida Blueberry Integrated Pest Management Guide (http://edis.ifas.ufl.edu/hs380) for detailed recommendations.
Weeds
January - February – Apply postemergence herbicide if weeds are at densities that hinder bush growth.
March – Warm season weeds will begin to emerge during this time. Early in emergence apply a preemergence herbicide tank mix with a postemergence herbicide. Select a preemergence herbicide with longer periods of control. Apply postemergence herbicide with a shielded sprayer to prevent drift onto the flowers or fruit.
Freeze Protection
Monitor forecasted and actual temperatures and utilize freeze protection strategies as needed. See EDIS publication HS968, Protecting Blueberries from Freezes in Florida (http://edis.ifas.ufl.edu/hs216).
Pruning
January – 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 5 to 6 years old to promote the growth of new canes. Low branches, weak growth, and damaged wood can also be removed at this time. See EDIS Publication HS1359, Pruning Southern Highbush Blueberry in Florida (https://edis.ifas.ufl.edu/publication/HS1359).
Bees
January – Managed honey bees and bumble bees provide essential pollination services in commercial blueberry fields. Have honey bees (and bumble bees if applicable) delivered early in bloom but after some flowers have opened; ideally, they should be placed in the field after 10% bloom but before 20% bloom. The recommended number of honey bee hives is 4-5 per acre. On large farms, hives should be distributed throughout the farm to the extent that it still allows access to bee providers. Hives should also be placed facing crop rows, but at a distance from crop rows so that they are not in the direct path of pesticide applications. Confirm health of colonies upon delivery; at least 8 frames per hive should have adults, and at least 6 frames per hive should have brood in the cells, with good forager activity into and out of the hives during fair weather. Average count of foragers returning to the hive should be about 40 foragers per minute during temperatures of 70°F or higher. Consider adding additional honey bee or bumble bee hives if there is a heavy, concentrated bloom across the farm and the potential for a high yield, or if the size of colonies is smaller than typical. See additional details in EDIS Publication ENY-172, Pollination Best Practices in Southern Highbush Blueberry in Florida (http://edis.ifas.ufl.edu/in1237).
February – March – Monitor appropriate level of bee activity into and out of the hives and on the blueberry bushes. Consider adding additional hives if there is a heavy, concentrated bloom across the farm or the hives are smaller or weaker than typical. Bee hives should be kept in the field through the end of bloom for all cultivars.
CREDIT
DOUG PHILLIPS, UF/IFAS Blueberry Extension Coordinator
