by Carrie Stevenson | Dec 9, 2013
How much is a 400-year old live oak tree worth? Can you buy one online, with free shipping, and charge it to the credit card? Pick one up at the local home improvement store? Ask Santa? Of course not. When admiring a tree that size, we have an innate sense of its value, but we would often have a hard time expressing it in dollars. How about a cluster of trees in a wooded lot? Are they worth more than the dollar store being built there? We are conditioned to appreciate the value of things because there’s a price tag on them. Unfortunately, natural phenomena do not have price tags, and many things that are “free” are often perceived to have no real value.
Planting a tree is an excellent way to insure clean air and water in the future. Photo credit: Carrie Stevenson
Trees, however, have value far beyond the price one might pay at a plant nursery. Their roots absorb polluted storm-water runoff, the primary cause of decreased water quality in Florida. Their leaves take in carbon dioxide and release the very oxygen we breathe. Providing homes for wildlife, fruit and nuts for human and animal consumption, compounds that form the basis of countless medications—trees provide innumerable benefits to ecosystems both local and worldwide. If a local government were to construct a facility or method that could filter the air and water at the same efficiency and volume of the trees in ones county, it would cost the community millions.
This street tree in Chicago was given a price tag to raise awareness of its value. Photo credit: Eric Stevenson
But how is is possible to capture these benefits in a way that we can relate to? Luckily, a partnership between arborists, engineers, and researchers with private industry, the US Forest Service, and the USDA has resulted in an excellent online tool called the National Tree Benefits calculator. Based on software called “i-Tree,” the calculator allows anyone to enter their zip code, choose from a list of common tree species, and using the diameter of a single tree, calculate its economic value. For example, a 15-inch live oak tree at the Escambia Extension office provides an annual benefit of $79 every year, increasing in value as it grows in girth and height. The website delves deeper into the tree’s value, placing storm-water uptake value at $23.77, electricity savings at $15.23, and the capability to remove 607 pounds of carbon dioxide from the atmosphere.
Extension Agents are currently working with youth in Escambia County to calculate these values for trees on their school campuses, local parks, and yards. When we’re finished, we will hang actual price tags on the trees showing their annual economic value to showcase these facts to residents of the community.
Interested in what kind of economic benefit that magnolia in the front yard is giving you? Check it out yourself at www.treebenefits.com, and let your neighbors know how valuable those trees can really be.
by Mary Salinas | Nov 4, 2013
For centuries, people annoyed with plant pests have used oils to control insects, mites, and even some fungal diseases. Current oil products are better than ever!
Sample oil products for pest control. Photo by Mary Derrick.
Commercially available horticultural oils are mineral oils from refined petroleum products. Impurities are removed and then an emulsifying agent is added that allows the oil to mix with water for application. Neem oil is a newer product that has become increasingly popular; the oil is an extract of the seeds of the neem tree.
What are some of the advantages of using an oil for pest control?
- Oils are inexpensive and easy to apply
- Oils can be used on most plants (check the label for a list!)
- Oils control a wide range of pests that feed on plants (again, check the label for a list of pests the product will control!)
- Oils pose a low risk to people, pets, and desirable beneficial predators
- Since oils kill pests by blocking their breathing holes (spiracles) and/or gumming up their mouthparts, there is no chance for resistance to develop
- One product can control both insects and some diseases like powdery mildew at once
- Oils can be combined with some other pesticides to provide greater control
[warning] Don’t combine with, or use within 30 days of, any sulfur based pesticide. The combination can harm your plants![/warning]
There are always drawbacks to a product. What are the drawbacks?
- Some plants (including cryptomeria, junipers, cedars, maples, and redbud) are damaged by oils – check the label!
- Ensure good coverage during spraying as pests must be contacted with the oil in order for the control to work
- Oils break down quickly and reapplication may be necessary
- Check the label for instructions on the temperature range when it can be used. Older formulations generally are safe when temperatures are in the 40 to 80°F range but ultra-fine oils can generally be safely applied during hotter weather.
For further information:
Natural Products for Insect Pest Management from UF IFAS Extension
Insect Control: Horticultural Oils from Colorado State University Extension
Less Toxic Pesticides from Clemson University Cooperative Extension
by Alex Bolques | Oct 25, 2013
The avid gardener has heard on many occasions that fall is the best time of the year to plant trees and shrubs. Correct! Now is the time to start a fruit orchard or an edible landscape. As the seasons transition into much cooler weather, now is the ideal planting season for hardy trees, shrubs and ground covers (Trawick, 2013).
In the fall, plants require less water to get established and stress factors associated with planting in full sun are reduced. Although weather is cool, soil temperatures continue to be warm enough throughout the season to promote root growth. Thus by planting in the fall, the plant becomes more established by having a better and more vigorous root system than a plant that is planted at springtime.
Deciding what to grow sometimes is limited by what is available in a given area. Mail and online sales can be tricky if for those unaware about which fruit species perofrms best in Northwest Florida. To aid in this planning process, a link to a University of Florida IFAS publication (HS1218) is included that contains a directory of certified Florida nurseries offering fruit and nut crops. While it was developed to assist farmers locate fruit and nuts cultivars in Florida, it is helpful to begin thinking about what to grow and where to find it. The publication also lists recommended fruit and nut species and cultivars for North Florida, including north-central Florida.
Fruitscapes is a University of Florida website dedicated to fruit trees in Florida, which will increase understanding of fruit tree cultural and pest management requirements for all readers. Also explore “Temperate Fruit Crops” . Bookmark this webpage and refer to it as needed. Also, consult with your county extension office in your area.
by Matthew Orwat | Oct 23, 2013
Image Credit: UF IFAS EDIS
From Dr. John P. Hayes”
“Florida Crossroads made a 28 minute video entitled “Seeds of Change” featuring the IFAS breeding efforts to create new varieties of blueberries, strawberries, tomatoes, and other crops, and the ways that these programs have influenced Florida industry.
For those of you who are familiar with our breeding programs, you’ll enjoy seeing some of our scientists on the screen. For those who aren’t familiar with IFAS development of new varieties, it is well worth the watch and I’d encourage you to do so. Our breeding program and the scientists engaged in breeding at UF are world class.”
by Alex Bolques | Sep 2, 2013
Gardeners that have Satsumas, commonly known as orange mandarin (Citrus reticulate), probably have experienced a caterpillar called Orangedog. It is a chewing insect that feeds on citrus foliage including Satsuma and a few other plant species. The caterpillar is dark brown with creamy-white, mottled markings and is the larval stage of the giant swallowtail (Papilio cresphontes). It is a striking, wonderfully “exotic”-looking butterfly that is very abundant in Florida.
Young larva of the giant swallowtail, Illustrating bird dropping mimicry.
Credit:
Donald Hall, University of Florida
Many who have encountered the caterpillar for the first time describe them as looking similar to bird droppings. They can grow up to 1.5 to 2 inches in length and are the larval stage of the adult giant swallowtail butterfly. Established Satsuma trees can easily withstand the loss of a few leaves by Orangedog feeding. Small or newly planted Satsumas can be infested with numerous Orangedog Caterpillars on occasion, especially a single tree growing in a landscape.
A simple control measure consists of finding and crushing eggs and larva (GH-026). Bt, a biological control for most caterpillar species, is effective but should rarely be used since the beauty of this butterfly far outweighs the damage caused by them.
Adult giant swallowtail, with wings closed.
Credit:
Donald Hall, University of Florida
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by Blake Thaxton | Aug 19, 2013
It is that time of year where mysterious webs have invaded pecan trees throughout the Southeast United States. This is definitely the case in the panhandle of Florida. Many have called into the extension office asking for identification of the web mass in their pecan trees. It is the Fall Webworm that has made a home in the pecan tree this fall.
Photograph by James Castner, University of Florida.
Photograph by Andrei Sourakov, University of Florida.
Fall Webworm
The adult fall webworm is a moth that is bright white in color and may have darker spots on its wings. The larvae of the moth are what lives in the tent web masses. Immediately when the larvae webworm hatches out of the eggs it begins to create its webs around foliage in which it will feed on.
Damage
The damage cause by the feeding of the larvae on the pecan trees is isolated to the leaves and they will not eat the nuts. If Defoliation is severe enough it can reduce the current years crop and the following years crop. Several years of defoliation can lead to death of the tree but this is not likely. Obviously the webs are ugly as well and if the tree is not only a producer of pecans but also functioning as an attractive shade tree in a ornamental since this can be a problem.
Control
In most commercial pecan production settings webworms are not very prevalent because of the spray programs implemented. For residential settings the best solution is to manually prune them out because of the lack of proper spray equipment to cover the entire tree. If the problem is bad enough call your local extension agent to get recommendations on products that could be used.
Sources:
Andrei Sourakov and Thomson Paris (2011, April) Fall webworm,Hyphantria cunea (Drury) (Insecta: Lepidoptera: Arctiidae: Arctiinae). Retrieved from http://edis.ifas.ufl.edu/pdffiles/IN/IN87800.pdf
Michael J. Hall. Fall Webworm. Retrieved from http://www.lsuagcenter.com/NR/rdonlyres/68665E57-A2F4-4030-A4E6-55821DCFBDD6/16783/FallWebworm_sheet_.pdf
