Suggested Blueberry Management Items for April through June
The table below lists suggested blueberry management items for April through June. 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.ufl.edu/publication/HS1363). Specific disease, insect, and weed controls are listed in the 2024 Florida Blueberry IPM Guide (https://edis.ifas.ufl.edu/publication/HS380), as well as in subject-specific 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 for field scouting tools, a monthly management calendar, information on all of the UF southern highbush blueberry cultivars, and a pesticides quick reference module (https://tosto.re/blueberryuf).
DOUG PHILLIPS, UF Blueberry Extension Coordinator
| Disease |
April - Apply suggested fungicides in rotation for control of anthracnose and/or Alternaria fruit rot; promptly harvest and cool ripe fruit. One tool growers may consider in timing spray applications is the Blueberry Advisory System (BAS) at www.agroclimate.org/BAS, which indicates when weather conditions are favorable for the development of anthracnose fruit rot.  May - Monitor for postharvest leaf diseases (rust, anthracnose, Septoria, target spot, Phyllosticta, and Cercospora) and apply recommended control measures. See EDIS Publication PP-348, FloridaBlueberry Leaf Disease Guide (https://edis.ifas.ufl.edu/pp348).  June - Scout for algal stem blotch. See UF EDIS Publication PP344, Algal Stem Blotch in Southern Highbush Blueberry in Florida (https://edis.ifas.ufl.edu/publication/PP344). Selectively prune out canes infected with algal stem blotch, Botryosphaeria stem blight, and dead canes. Monitor and manage leaf diseases. See UF EDIS Publication PP348, Florida Blueberry Leaf Disease Guide (https://edis.ifas.ufl.edu/publication/PP348). Apply Ridomil to help prevent Phytophthora root rot. See UF EDIS Publication PP374, Phytophthora Root Rot on Southern Highbush Blueberry in Florida (https://edis.ifas.ufl.edu/publication/PP374). On farms managing bacterial wilt, begin monthly through-irrigation or banded bed applications of a phosphorous acid product. See UF EDIS Publication PP332, Bacterial Wilt of Southern Highbush Blueberry Caused by Ralstonia solanacearum (https://edis.ifas.ufl.edu/publication/PP332).
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Insect Pests
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April - Monitor for gall midge and flower thrips and control as needed. Spray recommended insecticides to control spotted wing drosophila (SWD) and promptly harvest ripe fruit. If living north of Lake City and there is a history of blueberry maggot, establish yellow sticky traps to monitor for blueberry maggot adults. Also, in infested areas, start scouting for adult Diaprepes (citrus) root weevils (see EDIS Publication ENY999, Diaprepes Root Weevil on Southern Highbush Blueberry in Florida [https://edis.ifas.ufl.edu/in1241]) and adult flatheaded borers on the blueberry foliage. No pesticide is labeled in blueberry for citrus root weevil and flatheaded borer; however, some of the cover sprays for spotted wing drosophila will control these pests.
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| Weeds |
April - Apply postemergence herbicide if weeds are at densities that hinder bush growth. Carefully read preemergence herbicide labels because they have longer preharvest intervals than many of the postemergence herbicides. May - Apply a preemergence herbicide after harvest (tank-mix with a postemergence herbicide if weeds are at densities that hinder bush growth). This is an opportunity to incorporate preemergence herbicides with different modes of action, but shorter periods of weed control that are not good for the period when flower and fruit are present. June - Apply postemergence herbicide if weeds are at densities that hinder bush growth. Purple and yellow nutsedge will be actively growing during the hot and humid months. This is the best opportunity for control with postemergence herbicides. |
| Pruning |
May - After harvest is complete, hedge back bushes to stimulate new vegetative growth, immediately spraying with a suggested fungicide to minimize the risk of fungal pathogens infecting through pruning wounds. See UF EDIS Publication HS1359, Pruning Southern Highbush Blueberry in Florida (https://edis.ifas.ufl.edu/publication/HS1359).
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Leaf Tissue Samples |
June - Leaves should be collected for tissue nutrient analysis. Select samples from fully expanded leaves in the middle of a recent summer growth flush. |
