by Matt Lollar | Apr 23, 2020
I was recently sent some pictures of some unusual growths on pecan tree leaves. At first glance, the growths reminded me of the galls caused by small wasps that lay their eggs on oak leaves. However, after a little searching it became apparent this wasn’t the case. These galls were caused by the feeding of an aphid-like insect known as phylloxera.
Leaf galls caused by pecan phylloxera. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
The feeding from the phylloxera causes the young leaf tissue to become distorted and form a gall that encloses this female insect called a “stem mother”. These insects are rarely seen, but the hatch from over-wintering eggs in March/April just after budbreak. Once hatched, these “stem mothers” crawl to the new leaves and begin feeding. Once the gall forms, they start to lay eggs inside the gall. The eggs hatch inside the gall and the young phylloxera begin to feed inside the gall and the gall enlarges. The matured insects break out of the gall in May and some will crawl to new spots on the leaves to feed and produce more galls.
Pecan stem damage from phylloxera. Photo Credit: University of Georgia
There are two common species of phylloxera that infect the leaves. The Pecan Leaf Phylloxera seems to prefer young trees and the Southern Pecan Leaf Phylloxera prefers older trees. The damage from each of these insects is nearly indistinguishable. Damage from these insects is usually not severe and merely an aesthetic issue.
Once the damage is discovered on a tree, it is too late to control the current year’s infestation. There are currently no effective methods for control of phylloxera in home gardens. Soil drench applications witha product containing imidacloprid have been limited in their effectiveness.
by Daniel J. Leonard | Apr 1, 2020
There aren’t many more frustrating things than growing seemingly healthy tomatoes, those plants setting an abundance of flower and fruit, and then, once your tomatoes get about the size of a golf ball, having the fruit rot away from the base. This very common condition, called Blossom End Rot (BER), is caused one of two ways: by either a soil calcium deficiency or disruption of soil calcium uptake by the plant. Fortunately, preventing BER from occurring and then realizing an awesome crop of tasty tomato fruit is relatively simple and home gardeners have a couple of possible preventative solution!
Blossom End Rot damage. Photo Courtesy Larry Williams, Okaloosa County Extension.
- Soil Test & Lime if Needed. The only way to really know if your soil calcium level is sufficient is through a soil test. A complete soil test through the UF Soil Lab or other lab measures both raw nutrient levels and pH. Testing for pH is especially critical. For calcium, either already in the soil or in a supplement you apply, to be available to tomato plants, soil pH needs to be between 6.0-7. In more “acidic” soil pH below 6, nutrients like iron and aluminum become more available to your tomato plants, outcompeting calcium for uptake into the roots. We don’t want that. If your soil test indicates a pH below 6, it will give a lime recommendation somewhere between 3-5 lbs/100 ft sq of garden area to raise the pH to the sweet spot between 6.0-7.0 where your tomatoes will thrive.
- Use a Non-Lime Calcium Supplement. If you’ve had your soil tested and your pH is fine, adding more lime as a calcium supplement isn’t helpful. Using lime as an additional calcium source can actually lift pH above that 6.0-7.0 zone and cause other problems. At this point, once pH is where we want it, I like to add a non-lime calcium supplement. There are lots of options here. Traditional fertilizers labeled for tomatoes and veggies tend to have a good calcium content in the 6-10% range and work great. However, if you’re into organic gardening or just don’t need the extra nutrient value of a complete fertilizer, Gypsum is a good calcium supplement and is widely available. Regardless of which non-lime source you choose, apply at planting or shortly after and follow label rates for best results.
- Water Properly. Consistent watering is key in helping ward off BER. Though we know BER is generally
Healthy ‘Big Beef’ tomatoes grown in 2019 with a pH of 6.5, amended with Gypsum at planting, and watered regularly each day! Notice no BER. Photo courtesy the author.
caused by calcium deficiency, it can be induced by creation of distinct wet and dry periods from non-regular watering, interfering with calcium uptake and availability to the plant. So, while you may have adequate soil calcium, if you don’t water correctly, the condition will happen anyway! It’s also good to keep in mind that mature tomato plants use large quantities of water daily, so during the heat of summer, plants in containers may need to be watered multiple times daily to maintain consistently moist soil. Think about it, you don’t drink 8 glasses of water when you wake up and then never drink again throughout a hot day. A tomato is no different. Allowing your plants to wilt down before providing additional water ruins productivity and can induce BER.
Blossom End Rot, while one of the more destructive fates of tomatoes, is totally preventable by a little legwork early in the growing game from you! Soil test and change pH with lime if needed, add a shot of calcium through a tomato blend fertilizer or non-lime supplement like gypsum, and water regularly! Do these three things and you’ll be well on your way to a great crop of early summer tomatoes. If you have any questions about tomato blossom end rot or any other horticulture or agricultural topic, please don’t hesitate to reach out to us at the UF/IFAS Calhoun County Extension Office. Take advantage of this beautiful spring weather and get in the garden today! Happy gardening.
by Daniel J. Leonard | Jan 23, 2020
Cruciferous vegetables, mostly cool-season annuals in the Brassicaceae (formerly Cruciferae) family, are part of a healthy diet, prized for their high fiber content and unique sulfur-containing compounds known as glucosinolates. This vegetable family includes things many of us love (or love to hate) like Brussels sprouts, cabbage, cauliflower, collards, kale, mustard, turnips, bok choy, and Chinese cabbage. They’re also commonly grown in Panhandle gardens. However, as anyone who has grown these species knows, some are easier than others. For example, kale and radish are among the easiest of all plants to grow. But get beyond the basics and folks often run into difficulty with species like broccoli and cabbage. The high rainfall/humidity and frequent warm spells experienced here during the growing season often lead to serious pathogen problems, dooming my garden in years past. However, this winter, thanks to a couple of new cultivars, ‘Capture’ Cabbage and ‘Burgundy’ Sprouting Broccoli, I’ve enjoyed a plentiful supply of tasty crucifers!
4’x 8′ raised bed planted with ‘Capture’ on 24″ centers.
‘Capture’ Cabbage, developed by Bejo Seeds of California as a mid-season “white” fresh market cabbage for the South, has been an outstanding performer in my garden this year. Touted as highly resistant to Black Rot and Fusarium Yellows (by far the two most devastating pathogens of Cabbage), I had to try it for myself. I planted seeds 24” apart in my standard 4’ wide x 8’ long x 12” deep raised beds filled with mushroom compost and aged pine bark. Seedlings were fertilized once about three weeks after germination with a general purpose 10-10-10 fertilizer. The plants that developed have been extremely vigorous (I’m glad I paid attention to plant spacing guidelines on the seed packet!) and have not shown ANY evidence of disease, even through an unusually warm and wet winter that would have hammered older susceptible varieties. My plants have begun to develop heads and should be ready for harvest and the kitchen in just a couple more weeks! If you’ve had problems getting a cabbage from germination to head formation and harvest without serious disease pressure, give ‘Capture’ a try next fall!
‘Burgundy’ Broccoli in the author’s raised bed garden.
‘Burgundy’ Broccoli, developed by Elsom Seeds in the United Kingdom, is a unique variety sure to turn heads in your garden. True to its name, the prolific florets are a deep, purple color. Though the central “head” on ‘Burgundy’ is quite small, that’s not the primary feature anyway. Considered a “sprouting” broccoli, this cultivar puts out an abundance of side shoots that make ‘Burgundy’ sort of a cut-and-come-again broccoli, allowing for a long harvest window. Another advantage from a disease avoidance perspective is the short maturity time (the time from planting seeds to having harvestable shoots) of around 40 days! For perspective, a “regular” heading broccoli has a maturity of around 60 day, lots more time for problems to happen. In the same growing conditions described above for cabbage, ‘Burgundy’ performed amazingly well for me, growing strong, healthy stalks, large, unblemished leaves and an abundance of purple shoots with a nice flavor profile!
If you want to enjoy homegrown broccoli and cabbage but disease pressures have made your previous efforts unproductive, give ‘Capture’ Cabbage and ‘Burgundy’ Broccoli a try! These two selections have made it easier than ever to enjoy unique, homegrown, healthy cruciferous veggies. Keep these and other quality, disease-resistant cultivars in mind when planning your winter garden in 2020!
by Les Harrison | Oct 8, 2019
Mushrooms growing on the roots of trees is a bad sign. This indicates the roots are decaying and the tree will soon become (or already is) unsafe.
On the doorstep of autumn, the weather is making its seasonal change in north Florida. It has been a bit cooler in the mornings, but the afternoons still qualify as hot.
What the winds of October will blow in is still anyone’s guess, but last year it was Hurricane Michael. Unfortunately, the storm’s brunt came in causing severe damage to homes, businesses and marine enterprises in several counties.
October is typically the month when tropical cyclone activity lessens in the Atlantic, but accelerates in the Gulf of Mexico. While beastly events like Hurricane Michael are relatively rare, it only takes one such incident to necessitate recovery efforts and expenses for years, if not decades.
The prudent course of action is to prepare for the worst while hoping for the best. One area of preparation where residents can have a distinctly positive effect is readying their trees for the potential assault.
Damage from falling trees and limbs is a major cause of destruction during tropical storms and hurricanes. Removing potential problems before the storm can minimize harm to structures and injury to residents.
Trees in decline are especially hazardous. Their compromised health makes them subject to uprooting and breakage with far less force than would effect a healthy tree.
There are several key indicators for tree health. Any single factor or a combination can mark a tree as unsafe.
Mushrooms growing on or very close to trees is a sign the tree is dying. The fungus is not the cause of decline, but only an indicator of the eventual fate.
Spores of the mushrooms are scattered by wind and water. Landing randomly, most arrive on a site devoid of necessary resources and never sprout.
Those lucky spores which land on decaying wood will likely sprout and take nourishment from the rotting plant material. Their roots accelerate the decomposition of the wood by consuming the available material and exposing more of the tree to colonization by mushrooms.
Sites on trees and plants infected with mushrooms typically are break points when pressure or stress is applied. If the mushrooms are located at the base of the tree, it is likely to be detached from its roots and topple over in heavy winds.
Another indicator of tree health is its crown, or the uppermost branches and leaves. Healthy trees and plants have full, green, and growing crowns.
When the crown turns brown and the leaves drop off, it is a good indicator the tree’s days are numbered. The causes may be disease, lightning, or mechanical interruption of the root system.
Lastly, bifurcation or trunk forking is a sign of a structurally weak tree. This condition may display itself when the tree emerges from the ground or at an elevated place on the mature tree trunk.
When the wind direction stresses the tree with enough force at its angle of vulnerability, a collapse results. Unfortunately, there is no simple way to tell how much wind is required to produce the failure.
Any tree with these problems should be evaluated by a certified arborist and removed when necessary. It may result in an expense now, but can save on expenses, inconvenience and aggravation if a storm randomly removes the tree in the future.
The question must be asked: Is it worth the gamble to wait on the winds of October?
To learn more about the tree health in north Florida, read the UF/IFAS publication HOW TREES GROW IN AN URBAN ENVIRONMENT.
by Matt Lollar | Sep 7, 2019
A couple weeks ago, I was on a site visit to check out some issues on Canary Island Date Palms. The account manager on the property requested a site visit because he thought the palms were infested with scale insects. He noticed the issue on a number of the properties he manages and he was concerned it was an epidemic. From a distance, lower fronds were yellowing from the outside in and the tips were necrotic. These are signs of potassium deficiency with possible magnesium deficiency mixed in.
Transitional leaf showing potassium deficiency (tip) and magnesium deficiency (base) symptoms. Photo Credit: T.K. Broschat, University of Florida/IFAS Extension
Nutrient deficiencies are slow to correct in palm trees. It’s much easier to prevent deficiencies from occurring by using a palm fertilizer that has the analysis 8N-2P2O5-12K2O+4Mg with micronutrients. Even if the palms are part of a landscape which includes turf and other plants that require additional nitrogen, it is best to use a palm fertilizer with the analysis previously listed over a radius at least 25 feet out from the palms. However, poor nutrition wasn’t the only problem with these palms.
Upon closer look, the leaflets were speckled with little bumps. Each bump had a little white tail. These are the fruiting structures of graphiola leaf spot also known as false smut.
Graphiola leaf spot (false smut) on a Canary Island Date Palm. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Graphiola leaf spot is a fungal leaf disease caused by Graphiola phoenicis. Canary Island Date Palms are especially susceptible to this disease. Graphiola leaf spot is primarily an aesthetic issue and doesn’t cause much harm to the palms infected. In fact, the nutrient deficiencies observed in these palms are much more detrimental to their health.
Graphiola leaf spot affects the lower fronds first. If the diseased, lower fronds are not showing signs of nutrient deficiencies then they can be pruned off and removed from the site. All naturally fallen fronds should be removed from the site to reduce the likelihood of fungal spores being splashed onto the healthy, living fronds. A fungicide containing copper can be applied to help prevent the spread of the disease, but it will not cure the infected fronds. Palms can be a beautiful addition to the landscape and most diseases and abiotic disorders can be managed and prevented with proper pruning, correct fertilizer rates, and precise irrigation.
