Cooperative Extension Service
College of Agricultural and Environmental Sciences
The University of Georgia
George Boyhan, Extension Horticulturist-Vegetables
East Georgia Extension Center
Rosenwald Building, Third Floor
PO Box 8112
Georgia Southern University
Statesboro, GA 30460
912-681-5639 | 912-681-0376, Fax | 912-682-3481, mobile
Recently Lamar Zipperer and I hosted a tour for county agents in the East District to Florida. Dr. Eric Simonne, an Extension specialist at the University of Florida, was our guide during the trip.
Our first stop on the tour was in Hastings, Florida, which is noted for potato production. There are more than 18,000 acres of potatoes produced in this area with the majority being used in potato chip production. They use a unique irrigation system called "seep irrigation" that relies on manipulating the water table under the fields. In fact, if there was a theme for this trip, it was water use.
We then had a long drive to south Florida all the way to Homestead. Homestead is a unique production area with frost-free production almost every year. The soils in Homestead are made of calcium carbonate (limestone). Where this material has been pulverized naturally to a sand-like consistency, it is referred to as "marl." Machines have been used to crush the exposed limestone into a consistency of gravel, which is referred to as "rockland soil." Although not the best substrate for vegetable production, it will produce a crop with high value due to winter availability. Irrigation for these fields is from shallow wells (10-20 feet deep) dug into the porous limestone. Surprisingly, the recharge of this aquifer is such that saltwater intrusion is a problem only in places very near bodies of salt water, such as Biscayne Bay. Florida is so concerned about contaminating this aquifer that soil fumigants such as Telone are not even allowed to be tested as an alternative to methyl bromide.
Not all the trip dealt with vegetable production, and among our stops in Homestead was a visit to a bromeliad producer. Bromeliads are a group of plants that often exist as epiphytes on other plants. Spanish moss and pineapples are examples of bromeliads. The bromeliads this nursery was producing were strictly for ornamentals. Some very unusual specimens were being grown. The ower indicated that more than 100 different species were being produced at his location.
After leaving Homestead, we traveled to Immokalee, where the Southwest Florida Research and Education Center is located. My predecessor in this position, Charles Vavrina, works at this location. The visit began with a discussion of water issues in Florida. Florida is implementing best management practices for their growers, which they will have to follow in the coming years. There is concern in Florida about ground water pollution, and agriculture has been implicated as a major polluter with nitrogen and phosphorus use. It is still unclear how much agriculture affects ground water in Florida compared to urban areas, particularly when you consider suburban subdivisions and golf courses, which generally use large amounts of inorganic fertilizer. I believe, however, such issues will become more important to Georgia in the coming years.
We met with Gene McAvoy, the local county agent, who took us on a tour of the area. One of the interesting first stops was a visit to the research orange grove at the Center. Florida has been plagued with citrus canker, and to help control its spread, we had to walk through a carwash-like entrance and be sprayed with a disinfectant to help control this disease. The citrus specialist gave a short talk. One thing he mentioned was that citrus continues to develop sugar as it stays on the tree, so whether you're buying grapefruit or oranges, the best are available later in the season -- March and April.
Gene took us to visit local producers of squash and grape tomatoes. We hit it just right, as that night a frost came through that ended squash production and perhaps tomato production as well. We then visited a large-scale compost production facility. These folks had gotten into this business after visiting growers in Georgia. We ended our visit in Immokalee with a visit to a vegetable transplant producer. He was involved with large-scale transplant production on a contract basis. He was also producing foundation (first generation after tissue culture) strawberries of a new variety. Interestingly, he steam sterilizes all his flats from one season to the next. Some of our growers have had disease problems in production and this would be a good way to minimize these problems.
We spent the night in LaBelle and contined the next day with a visit in Dover at the Gulf Coast Research and Education Center. John DuVal, a Georgia graduate, works at this center. Strawberry production in this area is big business with more than 5,000 acres in production. This area is under heavy urban pressure with small strawberry fields often surrounded by housing developments. I don't think we saw a field that was greater than 20 or 30 acres. Growers wishing to dig new wells are required to be able to hold 1 inch of rain on their property before it runs off. We visited such a site, where the grower had built a holding pond that took up perhaps 1/2 of his acreage for this purpose. He was able to pull water from this holding pond, but its construction must have been costly.
We were able to visit Driscolls' packing shed in the Dover area as well. Driscolls packs locally grown strawberries under contract with the strictest quality control. All the berries are field packed with careful attention to quality and are checked again at the packing facility before being moved into the warehouse cooling facility. This attention to quality allows them to command a premium price for their product. In fact, loads that don't meet their standards can be sold but must be removed from boxes that contain their name.
The last day of the tour had two of the most interesting stops. First, we visited AgriStart III. This company grows foliage plants from tissue culture that are finished as 1-inch liners. Seventy-two 1-inch plants are produced in a flat. These plants are sold to other growers at $0.13 to $3.50 each! Our last stop took us to Stewart's Greenhouse, a foliage plant producer. This greenhouse operation was unique in their commitment to biological control of insect pests. While we were there, they were releasing thousands of lady bugs throughout the house. They routinely purchase and release several different predatory insects in their houses. Their facility is surrounded by developments and they are concerned about pesticide drift and possible complaints as well as the liability.
Organic growers have always said "feed the soil and let the soil feed the plant." This is generally done with addition of organic material in the form of composted manures, etc. In the south, however, there is no net increase in organic matter in the soil if the soil if tilled. This is because we have such a long growing season that organic matter is oxidized under these conditions.
The Soil Conservation Service has for years recommended no-till or reduced-till production to prevent soil erosion. This has required the use of specialized planting equipment pulled by larger horsepower tractors planting into the previous year's stubble. This is not without some pitfalls. Often previous crop stubble can have allelopathic effects on the current crop, reducing growth and yields.
Modifications ofo no-till methods that include strip-till and the use of transplants versus direct seeding can have some benefit in overcoming some of the shortcomings of no-till production. Recent work in southern Illinois with squash indicates that strip-till and no-till systems could work with yields comparable or better than tillage production with effective suppression of the previous cover crop. They used glyphosate or paraquat herbicide to kill or suppress the winter rye cover crop. Using the herbicide over the entire area as opposed to a strip resulted in better yields with the no-till or strip-till systems.
More work with these production practices needs to be done, but clearly they are effective alternatives to conventional tillage in some cases. Soil conservation and water conservation are but two areas that no-till production will address.
A Vidalia Onion Field Day is scheduled for April 18, 2002, from 12 noon until 3 p.m. This field day will be at the Vidalia Onion and Vegetable Research Center. We will have a sponsored lunch at noon followed by visits to the plots. There is a great deal of work underway on onions at the farm this year. Onion research at the farm includes variety testing, fungicide trials, fertility work and direct seeding onions -- to name a few subjects. For more information about the field day, please contact me at 912-681-5639 or Randy Hill (farm superintendent) at 912-565-7822. I encourage you to notify your growers to come out to the farm to see what we're doing on their behalf.
From My DeskInformation in the no-till/reduced-till story comes in part from an article in HortTechnology, "Reduced Tillage Practices for Summer Squash Production in Southern Illiinois" (12:114-117). This article is followed in the same issue with an article on sweet corn production with no till versus tillage and cover crop effects. It, too, shows some promise, particularly for use of vetch as a substitute for inorganic nitrogen.
You may have noticed that it's March and this is the February issue. After the Florida tour, I've been preparing my dossier for the past three weeks, so I'm way behind on everything. Talk to you next month -- I mean this month (in a couple of weeks anyway).