Florida Blueberry Leaf Disease Guide
Douglas A. Phillips, Norma C. Flor, and Philip F. Harmon Southern highbush blueberry (SHB) cultivars are commercially grown throughout...
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By Doug Phillips
Blueberry Extension Coordinator
Doug Phillips is the University of Florida blueberry extension coordinator, and is the primary point of contact for blueberry growers for issues and questions regarding disease, insect pests, management practices, etc. He will coordinate with subject matter experts in Gainesville as needed to assist growers in identifying solutions and best practices for production issues. Doug also collects data and evaluates selections at the UF breeding program trial sites in central and south-central Florida, and provides grower feedback to UF breeding, pathology, entomology, pollination, weed science, and management practice experts.
What To Do After a Hurricane
Nov 1, 2024 / Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
The following information is from UF EDIS Publication HS1342 “Impacts of Hurricane Damage on Southern Highbush Blueberries” (https://edis.ifas.ufl.edu/publication/HS1342)
One should consistently apply the following best management practices after a hurricane to alleviate or avoid additional plant stress:
Southern Red Mite Management
Sep 1, 2024 / Dr. Oscar Liburd, Professor, UF/IFAS, Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
The peak in southern red mite populations vary depending on the region in the state where the blueberry planting is located. If your planting is in north-central Florida (Alachua, Marion, Columbia, and Putnam counties) the peak is typically during late September and October. However, if you are in the central or south-central region (Polk, Hardee, Hillsborough, Highlands, and DeSoto counties) the peak occurs later, from late November to February when temperatures are still high and rainfall is low, as they prefer dry, dusty conditions.
The Evergreen Blueberry Production System in South and Central Florida
Aug1, 2024 / Dr. Jeff Williamson, Professor, UF/IFAS, Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
The two production systems used by Florida blueberry growers are the deciduous (or dormant) system and the evergreen system. Under the deciduous system, plants are allowed to go dormant in late fall and defoliate. Many growers using this system apply hydrogen cyanamide in early winter to help promote vegetative budbreak to support earlier flowering and fruit set, and to concentrate fruit ripening.
Summer Fungal Leaf Diseases
July 1, 2024 / Dr. Phil Harmon, Professor, Plant Pathology, UF/IFAS, Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
Fungal leaf diseases can be a problem for Florida blueberry growers during summer months, including anthracnose, Phyllosticta leaf spot, rust, and target spot. This post is a quick reference guide to identifying these diseases from the symptoms (although some of these diseases can have symptoms that appear to be similar) and suggested chemical controls.
Managing Chilli Thrips in Florida Blueberry Fields
June1, 2024 / Dr. Oscar Liburd, Professor, UF/IFAS, Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
One of the most problematic insect pests on blueberries in Florida is chilli thrips, (Scirtothrips dorsalis). It was first recorded in blueberries in Florida in 2008. Chilli thrips typically feed on the new vegetative growth of blueberry after summer pruning, although in recent years they have been observed in mid to late May on new foliar flushes.
Postharvest Pruning on Southern Highbush Blueberry in Florida
May1, 2024 / Dr. Jeff Williamson, Professor, UF/IFAS, Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
One of the most important activities in May or early June for Florida blueberry growers is postharvest hedging, which is typically done shortly after harvesting is completed. Delaying hedging until mid-to-late summer may negatively impact floral bud differentiation and yield. Hedging promotes the growth of the canopy and new fruiting wood, and is important for vigorous, healthy growth (Figure 1). In addition to promoting vegetative growth, hedging can help reduce disease pressure by removing pathogens such as rust and Septoria from the field. It will also open up the plant canopy to allow for better air flow and sunlight penetration (promoting faster foliage drying and lower levels of fungal disease) and better coverage when spraying pesticides. Hedging can also remove damaging insects from the plant’s top growth, including wax scale and blueberry bud mite.
Managing Spotted Wing Drosophila in Florida Blueberries
Apr 4, 2024 / Dr. Oscar Liburd, Professor, UF/IFAS, Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
Spotted wing drosophila (SWD), Drosophila suzukii (Matsumura), is an invasive pest that was introduced into Florida in 2009. As of June 2015, it had spread to most of the fruit-producing states in the US and more than 30 counties in Florida. The highest numbers in Florida have been found in Citrus, Alachua, Marion, Orange, and Hillsborough Counties. Surveys of this pest from 2015–2018 indicate that the pest has historically been active throughout the year with peak activity from April to May when blueberry production is highest, although some growers in central Florida began to observe SWD on their farms during March 2024.
Managing Anthracnose Fruit Rot
Mar 1, 2024 / Dr. Phil Harmon, Professor, Plant Pathology, UF/IFAS, Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
With a wet El Niño winter forecasted for Florida in 2024, growers should focus on plans to minimize and manage fruit fungal diseases. Anthracnose fruit rot is the most prevalent and significant winter and early spring disease in Florida.
Anthracnose fruit rot (AFR) is caused by the fungus Colletotrichum gloeosporioides. Its development is highly dependent on favorable weather conditions, including extended leaf wetness duration. Symptoms typically begin to appear as berries start to ripen, including the development of sunken lesions, shriveling, and fruit softness, along with the eruption of orange or salmon colored spores. In some cases, symptoms do not appear until after the fruit is harvested and stored. However, infection can occur as early as bloom.
Managing Flower Thrips in Southern Highbush Blueberry in Florida
Feb 8, 2024 / Dr. Oscar Liburd, Professor, UF/IFAS, Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
The Florida flower thrips (Frankliniella bispinosa Morgan) are a pest of southern highbush blueberries in Florida that are present during bloom. Larvae and adults feed on all parts of the flowers (ovaries, styles, petals) and developing fruit. Feeding damage can reduce pollination of the injured blooms, and therefore the quantity and quality of fruit produced from those blooms. Adult females can also cause indirect injury to fruit when laying their eggs inside flower tissues (Figure 1 c). The newly hatched larvae create holes in the flower tissue when they emerge, resulting in scarring of the fruit.
Managing Leaf Rust in the Evergreen Production System
Jan 9, 2024 / Dr. Phil Harmon, Professor, Plant Pathology, UF/IFAS, Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
Under the evergreen production system for southern highbush blueberry (SHB), which is used extensively in the south-central and central regions of Florida, blueberry plants do not go dormant and are harvested early in the season. One of the primary management necessities in the evergreen system is to keep the foliage healthy and intact through the harvest season. A significant challenge to accomplishing this can be fungal leaf disease, in particular rust, which must be managed from late fall through harvest.
Good Pollination Practices in Florida Blueberry Fields
Dec 1, 2023 / Dr. Rachel Mallinger, Assistant Professor, Pollinator Ecology and Conservation, UF/IFAS, Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
Southern highbush blueberry (SHB) is dependent upon pollinating insects for adequate fruit set. Symptoms of insufficient pollination include low ratios of fruit to flowers, delayed petal fall, petals turning brown while still on the bush, small berries, and a low number of seeds per berry. Implementing good pollination best practices can help minimize the likelihood of poor pollination.
Time to Start Thinking About Freeze Protection
Nov 5, 2023 / Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
Blueberries bloom in late winter or early spring in Florida, making the flowers and young fruit susceptible to freeze and frost injury. Killing freezes can occur as late as mid to late March throughout much of Florida, long after the initiation of bloom, especially for early-ripening southern highbush blueberry cultivars. If some method of freeze protection is not employed, freezes during flowering and early fruit development can be one of the greatest threats to southern highbush blueberry production in Florida.
Blueberry Gall Midge Management
Oct 2, 2023 | Dr. Oscar Liburd UF/IFAS, Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
Blueberry gall midge larvae feed on blueberry floral bud tissues, causing brown lesions, and bud death and abortion (Figure 1). When there is heavy gall midge injury, the bloom will typically be lighter since many of these buds will abort, resulting in decreased fruit set. It should be noted that poor fruit set and excessive dropping of undeveloped green fruit can also be caused by poor pollination.
Southern Red Mite Management
Sep 22, 2023 | Dr. Oscar Liburd UF/IFAS, Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
The peak in southern red mite populations vary depending on the region in the state where the blueberry planting is located. If your planting is in north-central Florida (Alachua, Marion, Columbia, and Putnam counties) the peak is typically during late September and October. However, if you are in the central or south-central region (Polk, Hardee, Hillsborough, Highlands, and DeSoto counties) the peak occurs later, from late November to February when temperatures are still high and rainfall is low, as they prefer dry, dusty conditions.
The Evergreen Blueberry Production System in South and Central Florida
Aug 15, 2023 | Dr. Jeff Williamson, professor and Extension specialist, UF/IFAS, Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
The two production systems used by Florida blueberry growers are the deciduous (or dormant) system and the evergreen system. Under the deciduous system, plants are allowed to go dormant in late fall and defoliate. Many growers using this system apply hydrogen cyanamide in early winter to help promote vegetative budbreak to support earlier flowering and fruit set, and to concentrate fruit ripening. With the evergreen system, the plants never go dormant, and one of the major production goals is to keep the prior year’s foliage healthy and intact though harvest, to support early fruit maturity.
Summer Fungal Leaf Diseases
July 11, 2023 | Dr. Phil Harmon, Professor, Plant Pathology, UF/IFAS, Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
Fungal leaf diseases can be a problem for Florida blueberry growers during summer months, including anthracnose, Phyllosticta leaf spot, rust, and target spot. This post is a quick reference guide to identifying these diseases from the symptoms (although some of these diseases can have symptoms that appear to be similar) and suggested chemical controls. Additional information on leaf diseases can be found in UF EDIS Publication PP348, Florida Blueberry Leaf Disease Guide (https://edis.ifas.ufl.edu/publication/PP348).
Managing Chilli Thrips in Florida Blueberry Fields
June 12, 2023 | Dr. Oscar Liburd, Professor, Fruit and Vegetable Entomology, UF/IFAS, Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
One of the most problematic insect pests on blueberries in Florida is chilli thrips, (Scirtothrips dorsalis). It was first recorded in blueberries in Florida in 2008. Chilli thrips typically feed on the new vegetative growth of blueberry after summer pruning, although in recent years they have been observed in mid to late May on new foliar flushes
Pruning Southern Highbush Blueberry in Florida
May 2, 2023 | Dr. Jeff Williamson, Professor, UF/IFAS, Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
Pruning is an essential part of blueberry production. It is used to promote postharvest growth of new foliage and fruiting wood, balance vegetative and reproductive growth, reduce disease and insect pressure, assist in mechanical harvesting efficiency, promote new cane growth and plant longevity, and help establish new plantings.
Flower Thrips Management in Southern Highbush Blueberry in Florida
Feb 3, 2023 | Dr. Oscar Liburd, Professor, UF/IFAS and Doug Phillips, Blueberry Extension Coordinator, UF/IFAS
Flower thrips (Frankliniella bispinosa Morgan) are a pest of southern highbush blueberries in Florida during bloom. Larvae and adults feed on all parts of the flowers including ovaries, styles, petals, and developing fruit. This feeding damage...
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