Citrus leafminer injury. Photo: James Castner
Spring is in full swing and citrus trees have begun actively flushing. With the new flush comes an array of insect pests. One of the most common being the citrus leafminer. The citrus leafminer is a small white moth, about 2.4 mm in length. It is more easily detected during its larval stage by the serpentine larval mines it produces on the underside of citrus leaves.
Citrus leafminer adult. Photo: James Castner
The larvae of the citrus leafminer feed on the new growth or flush of citrus causing serpentine mines to form under the leaf cuticle. This can result in leaf curling and distortion. Citrus leafminer injury to foliage can stunt the growth of young trees and in areas where the citrus canker pathogen is present, provide an opening for infection.
Distortion and leaf curling caused by citrus leafminer. Photo: Danielle Sprague
The term ‘flush’ is commonly used to describe the new foliar growth between bud break and shoot expansion. Citrus trees usually have several flushes per year, depending upon cultivar, climate and crop load. Generally, most citrus cultivars in our area have around three flushes. The main flush is the spring flush in late winter/early spring. Following that, two additional flushes occur around the end of June and late September.
Citrus leafminer on young flush. Photo: Danielle Sprague
Adult leafminers require the new citrus flush for development. Eggs are laid within the flush. After two to ten days, the larvae emerge and feed causing the mines to occur. Larvae are protected within the leaf and therefore difficult to control. Pupation occurs within the leaf mine and takes anywhere from six to 22 days, depending upon temperature. Adults emerge around dawn and are most active in the morning and evening. In Florida, one generation of citrus leafminer is produced about every three weeks but populations increase when citrus trees are flushing.
In Florida, several natural enemies assist with reducing citrus leafminer populations. Studies have shown that predation from natural enemies can reduce leafminer populations by 90%. Primary predators of citrus leafminers include ants, lacewings and spiders. A parasitic wasp, Ageniaspis citricola was introduced into Florida and has become established. The parasitic wasp attacks the immature stages of citrus leafminer. Ageniaspis citricola can be requested and obtained for free from the Florida Department of Agriculture and Consumer Services (FDACS). Because it is a specialized parasitoid of the citrus leafminer larval stage, it should be released only when mines start to become visible on flush.
Citrus leafminer can be difficult to control with insecticides due to the fact that they are within the leaf and protected. Applications of insecticides require proper timing and may require repeat applications. For a full list of insecticides, contact your local Extension Office.
For more information on citrus leafminer, use the links to the following publications:
Citrus Leafminer, Phyllocnistis citrella Stainton (Insecta: Lepidoptera: Phyllocnistinae)
Citrus Leafminer Control – UGA
Twisted and tangled kiwifruit plants in a North Florida orchard. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
When we think of kiwis, we think of fuzzy, slightly tart, egg-shaped fruits from somewhere in the Southern Hemisphere. However, there is a species (Actinidia chinensis) of kiwi with smooth skin, sweet taste, and golden color.
Commonly available cultivars of this species are ‘AU Golden Dragon’ and ‘AU Golden Sunshine’. Most years, kiwis won’t produce much of a crop in North Florida because they won’t receive enough chill hours, but they might be fun to try for the adventurous gardener.
- Site Selection – Kiwis perform best in well-drained soils with a neutral pH (around 7.0). High winds may cause canes to break and scar fruit, so a windbreak is recommended or they can be planted near a structure.
- Irrigation – Kiwis need a lot of water during the summer. This is partly due the their large leaves that transpire rapidly because of surface area. Newly planted kiwis should be watered deeply at least once a week.
- Fertilization – Fertilize kiwis three times a year (January, April, and June). Do not apply fertilizer after the month of July to reduce the incidence of cold injury in the winter.
- Insects and Diseases – The most common insects of kiwis are mites and scales. To reduce the incidence of disease, plant kiwis at least 15 feet apart and train on a trellis.
- Training – A T-bar trellis, similar to the system used to train grape vines, or a pergola should be used to provide support for the plants. Once the plants are established (2 to 3 years after planting), about a third of the vines should be removed each year.
An illustration of a T-bar trellis system. University of Georgia Extension
Kiwis are wind- and insect-pollinated. Good growing conditions and insect pollination help increase fruit size. Male and female plants are required for good fruit yields. At least one male (pollen producing) plant should be planted for every four female (fruit producing) plants.
Kiwi plants will soon be planted for evaluation at the West Florida Research and Education Center in Jay, FL. Please stay tuned for future data! For more information on growing kiwis in the Southeast, please visit these webpages:
Kiwifruit Production Guide
Bringing Home the Gold – Auburn horticulture alum gets kiwifruit orchard off the ground in Reeltown
Citrus growers from across the Florida Panhandle, as well as southern Georgia and Alabama are invited to attend the 2019 Citrus Health Forum. The workshop will be held at the UF/IFAS North Florida Research and Education Center in Quincy (155 Research Road, Quincy, FL). Registration begins at 8:30 AM EST with the meeting starting at 9:00 AM and concluding at 3:00 PM. The workshop registration fee is $10 and includes refreshments and lunch.
A.M (all times Eastern)
9:00 Welcome – Dr. Glen Aiken, UF/IFAS NFREC-Center Director
9:15 Cold Hardy Citrus Varieties for North Florida – Dr. Pete Andersen, UF/IFAS NFREC Horticulture
9:45 Arthropod Pests of Citrus – Dr. Lauren Diepenbrock, UF/IFAS CREC Entomology
10:15 Unexpected Diaprepes abbreviatus Infestations in North Florida – Dr. Russ Mizell, UF/IFAS NFREC Entomology
10:45 Citrus Canker, Alternaria and Scab Diseases of Citrus – Dr. Megan M. Dewdney, UF/IFAS CREC Plant Pathology
11:15 Phytophthora Management and HLB Basics – Dr. Evan G. Johnson, UF/IFAS CREC Plant Pathology
12:45 Detection of HLB by Canines – Dr. Tim R. Gottwald, USDA Plant Pathology
1:10 Asian Citrus Psyllid Distribution and Management in North Florida – Xavier Martini, UF/IFAS NFREC Entomology
1:35 Enterprise Budgets for Satsuma in North Florida – Dr. Kevin R. Athearn, UF/IFAS Economist
2:00 Detection of HLB by Canines: Field Demonstration – Bill Moraitis, F1K9
To register, please contact Charlene at firstname.lastname@example.org or by phone at 850-875-7105. For more information on the meeting, or to help sponsor the event, contact Xavier Martini at email@example.com or 850-875-7160.
I’m a native of Georgia, growing up just south of the region known as “peach country”. To me, there’s nothing better than a ripe, juicy peach on a summer day. I thought I had seen it at all when it came to peaches. That changed on a trip to the southwest U.S.
A few years ago, I was fortunate to make the voyage to Utah for the National Association of County Agricultural Agents annual meeting. A small group of county agents also participated in a pre-tour of the southwest region of Utah. This is where I found a treasure in the desert, as a host extension agent shared some of his oddly shaped, Saturn peaches from a nearby orchard.
The Saturn peach is a favorite in Utah and a favorite for hundreds of years in Asia. This is an asymmetrically shaped peach, with white, firm flesh. Some refer to this as a “donut peach”. It is an interesting fruit, that I must admit was one of the most delicious peaches that I’ve ever eaten.
Figure 1. “UFO” Peach.
Credit: Ali Sarkhosh, Mercy Olmstead, Jose Chaparro, Pete Andersen and Jeff Williamson. UF/IFAS Extension
I began to ponder why this peach variety was one that I had never encountered? After consulting with extension agents in neighboring southeastern states, I found that many universities had experimented with the variety. However, pitfalls in climate acclimation, mechanical harvesting (because the fruit is not round, harvesting equipment can damage) and marketing were discouraging. From a large commercial production interest, even if a viable yield could be grown in the region and custom designed harvesters were feasible, hurdles would still remain regarding the difficulty of marketing an introduced variety that has an unfamiliar and imperfect shape, versus well established varieties that can be graded as select. However, a healthy market may exist for small farms as novelty crop.
Furthermore, in 2002 UF/IFAS researchers breed and patented a similar variety of the Saturn peach that thrives anywhere in Florida. The Australia saucer peach was used to breed this new variety, known as the flying saucer or “UFO”. This peach has non-melting flesh with that unique donut shape, not unlike the Saturn. These trees are large and vigorous growing, with a semi-upright growth habit. The UFO produces moderately heavy crop loads of large, firm fruit with yellow flesh and semi-freestone pits that has a fruit development period of 95 days. As seen in figure 1, the skin develops 50–70% blush. This cultivar is particularly susceptible to ethylene that is released during dormant pruning, which can result in significant flower bud abortion. Thus, pruning is only recommended during the summer period.
Where do I find such a tree? Growers can purchase from nurseries who are licensed by the University to grow patented varieties. What about homeowners? Check your local garden centers. Now is great time to plant.
For more information please contact your local extension office.
Supporting information for this article obtained through past interviews of Dr. Wayne Sherman, Professor Emeritus, Department of Horticultural Sciences, UF/IFAS as well as from the following the UF/IFAS EDIS publication: “Florida Peach and Nectarine Varieties” by Ali Sarkhosh, Mercy Olmstead, Jose Chaparro, Pete Andersen and Jeff Williamson: https://edis.ifas.ufl.edu/pdffiles/MG/MG37400.pdf
UF/IFAS Extension is an Equal Opportunity Institution.
The Chickasaw plum is covered in beautiful small white flowers in the spring. Photo credit: UF IFAS
The native Chickasaw plum is a beautiful smaller tree (12-20 ft mature height) that is perfect for front yards, small areas, and streetscapes. True to its name, the Chickasaw plum was historically an important food source to Native American tribes in the southeast, who cultivated the trees in settlements well before the arrival of Europeans. They typically harvested and then dried the fruit to preserve it. Botanist-explorer William Bartram noted the species during his travels through the southeast in the 1700’s. He rarely saw it in the forests, and hypothesized that it was brought over from west of the Mississippi River.
One of the first trees to bloom each spring, the Chickasaw plum’s white, fragrant flowers and delicious red fruit make it charmingly aesthetic and appealing to humans and wildlife alike. The plums taste great eaten fresh from the tree but can be processed into jelly or wine. Chickasaw plums serve as host plants for the red-spotted purple butterfly, and their fruit make them popular with other wildlife. These trees are fast growers and typically multi-trunked.
Almost any landscape works for the Chickasaw plum, as it can grow in full sun, partial sun, or partial shade, and tolerates a wide variety of soil types. The species is very drought tolerant and performs well in sandy soils.
The plum is in the rose family and has thorns, so it is wise to be aware of these if young children might play near the tree.
Winter is ideal tree-planting time in Florida. While national Arbor Day is in spring, Florida’s Arbor Day is the 3rd Friday of January due to our milder winters. This year, Escambia County’s tree giveaway will include Chickasaw plums, so if this tree sounds like a great addition to your landscape, come visit us on January 19 and pick one up.
For more information about tree selection in northwest Florida, contact your local county Extension office.
A grape vineyard. Credit: Peter Andersen, UF/IFAS.
The classic muscadine (Vitis rotundifolia). Credit: Carl Hunter. USDA-PLANTS Database.
This is the time of year to be on the watch for purple-stained sidewalks and driveways – a sign that ripe muscadine grapes are falling from above. The muscadine grape (Vitis rotundifolia) is a native Florida vine that has been enjoyed by Native Americans, colonists, and contemporary Floridians alike. In addition to the classic muscadine and scuppernong, a light-colored variety of muscadine, there are five other native species of grape (Vitis spp.) to be found growing in natural areas or along woodland edges. All are edible, however, the muscadine has the largest, tastiest fruit.
Many north Florida gardeners have some species of grape growing in their landscapes and consider it a weed due to its aggressive growth. Unfortunately, since the vines are functionally dioecious (separate male and female plants) and most wild plants are male, it is unlikely that those annoying grapevines at the garden’s edge will ever bear fruit. But every now and again, luck strikes! That’s why finding a purple-stained sidewalk or parking area is such an exciting event. I have some of these locations saved in my memory to visit this time of year, especially since all the grapevines in my own property have yet to bear one fruit! If necessary, control methods for grapevine in a landscape include repeated pruning back or the use of herbicides. Muscadines and other grapes are intolerant of shade so will eventually perish if cut back and located under a canopy of trees or shrubs.
The bronze-colored scuppernong. Credit: Peter Andersen. UF/IFAS.
Good News! There are plenty of varieties bred for the backyard and commercial fruit grower. Since muscadines are native, they require little, if any, pesticides, making them a great choice for a sustainable landscape or orchard. The vines can be grown up an arbor or a complete vineyard trellis system can be built for maximum harvest. A UF/IFAS fact sheet called “The Muscadine Grape” (publication #HS763) contains all the information needed to choose the right variety, design a vineyard, and implement the best pruning, irrigation, and fertilization schedule.
Whether fresh off the vine or in jams or wine, muscadines are a sweet, summery treat for Floridians.