Hurricanes and tropical storms can result in damage to Florida blueberry farms in three primary ways – wind damage, flooding, and disease resulting from plant damage or post-storm environmental conditions.

Wind Damage
Hurricane or tropical storm-force winds can cause significant damage to blueberry plants, including defoliation and uprooting. Significant defoliation of blueberry plants was observed on some farms in South Florida after recent hurricanes, as well as wind damage to the remaining foliage (Figures 1 and 2). Early fall flower bud initiation and development depend on plants having a full and healthy canopy of foliage. Defoliation during or just prior to this time can affect bloom time and reduce the number of flower buds that develop, and/or the number of berries produced per flower bud. The impact of defoliation and other damage to remaining leaves can be even more significant on blueberry plants grown in the evergreen system, where it is important to maintain healthy foliage to achieve early yields of high-quality fruit.

Figure 1. Defoliation from hurricane force winds
Credits: D. Phillips, UF/IFAS

Figure 2. Blueberry leaf wind damage
Credits: D. Phillips, UF/IFAS

Hurricane-force winds can also cause damage by uprooting blueberry plants, resulting in plant damage and significant costs in labor and materials to reset and stake these plants. Breakage of woody stems and roots can significantly impair the transport of water and nutrients throughout the plant, resulting in delayed and stunted growth and severe plant stress that can persist for weeks or even months. Wounds also provide entry points for stem and root pathogens, resulting in disease including Botryosphaeria stem blight, which can sometimes occur months after the wind damage and plant stresses take place.

Flooding

Flooding and standing water in blueberry fields following a storm can create both physiological and disease damage to blueberry plants, which generally do not tolerate saturated conditions well.

Root death can occur when there is no oxygen in the root zone due to saturated conditions (known as hypoxia). Flooding can reduce root and overall plant growth, the number of leaves or leaf expansion, nutrient uptake, and may result in smaller flower buds and fruit. Minimizing the length of time that flooded conditions persist by pumping water from the field may help to limit these damages. Diseases that thrive in flooded conditions include Phytophthora root rot (see EDIS Publication PP374, Phytophthora Root Rot on Southern Highbush Blueberry in Florida https://edis.ifas.ufl.edu/publication/PP374), as well as bacterial wilt caused by Ralstonia solanacearum (see EDIS Publication PP332, https://edis.ifas.ufl.edu/publication/PP332). Saturated conditions with wounding of roots are an ideal scenario for infection of blueberry roots by these pathogens.

Disease
For plant disease to begin in the blueberry field, the following three factors must be present: an active pathogen, favorable environmental conditions for infection and disease development, and a susceptible host. Each of these factors can be affected by a hurricane or tropical storm.

Pathogen — High winds and rising waters can spread pathogens into and throughout a production field where they may not have been present.
Environment — Flooded soils and extended rain events associated with a major storm, along with typical hot and humid weather during summer and early fall, are ideal conditions for successful infections and continuing disease spread in blueberry plants.
Plant Host — Blueberry plants can suffer significant stress from the types of storm damage discussed above. Stressed and wounded plants have fewer defenses against infection and disease development. Diseases like Botryosphaeria stem blight often become more common in a field of stressed plants, and stressed plants are more likely to die from the disease.

Storm Recovery
Successful recovery from storm damage can be significantly helped by having good preparations in place before a storm hits.

Before the Storm — Farm Preparations
Check fields for surface water drainage. Ensure that ditches, canals, areas between beds, and the ends of rows are clear and that water can flow freely out of production fields.
Make sure to have sufficient diesel fuel on hand to operate farm equipment and drainage pumps.
Check that generators and chainsaws are working properly.
Scout for potential debris and secure items that may be propelled by strong winds before the storm.
Purchase materials for resetting plants blown over during the storm (e.g., bamboo or fiberglass stakes and tie tape).
Purchase mefenoxam containing products (e.g., Ridomil, Ultra Flourish, Orondis, etc.) and phosphorous acid products (“phytes”) to manage Phytophthora root rot in case of prolonged flooded conditions.
Secure important records and documents, including production records, financial records, and insurance documents.
The Florida Division of Emergency Management has additional hurricane preparation information at https://www.floridadisaster.org/planprepare/preparing-for-hurricane-season/.

After the Storm—Management Suggestions

• The following best management practices should be consistently applied after a hurricane or tropical storm to alleviate or avoid additional plant stress:
• Reset and stake uprooted lodged plants as quickly as possible to reduce losses from desiccation and plant death.
• Examine irrigation systems when waters recede to make sure they are functioning properly.
• Repair raised beds and weed cloth, and resume bed irrigation and pH monitoring, adjusting as necessary.
• Carefully monitor irrigation after the storm and rains pass to prevent further drought stress in plants with damaged root systems.
• Resume scheduled fertilizer applications after waters have receded and when beds begin to drain. Consider reducing the rates of nitrogen where plants have been stressed, and begin to slowly return to recommended timings and rates for the given deciduous or evergreen production system.
• Look for disease symptoms and insect pests.
• Apply management and control suggestions as appropriate; see EDIS Publication HS1156, “2024 Florida Blueberry Integrated Pest Management Guide” (https://edis.ifas.ufl.edu/publication/HS380).

Ideally, applications of Ridomil or another mefenoxam fungicide that help prevent Phytophthora root rot will have already been made in early summer prior to hurricane activity. Two applications of these products per year are allowed, and where a second application was not made earlier, consider making that application prior to a predicted storm impact when possible. When not possible, the second application can be made after waters have receded either in a banded bed application or through certain irrigation systems. (Consult the product label for more details.) These applications can help prevent root rot development, but they will not cure severely affected plants or those dying from flooding (hypoxia). Also consider making foliar applications of phosphorous acid products (“phytes”) when field conditions allow.
Good recordkeeping is important to document any losses suffered. Include detailed production records from prior years and pictures and video of all areas of the farm affected by the storm.
Information on USDA hurricane, disaster, and other assistance to growers is discussed in EDIS Publication HS1485, Government Agency Resources for Florida Blueberry Growers (https://edis.ifas.ufl.edu/publication/HS1485).

CREDITS:
DOUG PHILLIPS, Blueberry Extension Coordinator, UF/IFAS
DR. PHIL HARMON, Professor, UF/IFAS
DR. JEFF WILLIAMSON, Professor, UF/IFAS