SARASOTA, Fla. (AP) — A small company in Sarasota is experimenting with a product that could change the way farmers grow crops in Southwest Florida.
Apollo Sunguard, owned by Kevin Connelly since 1997, makes shade structures featuring polyethylene knit cloth on metal frames.
Most of its business comes from contracts with school districts or parks departments, although Connelly is always seeking new applications, such as the shaded electric car recharge station he built with General Electric at the Florida House.
Now, in addition to protecting people and cars from the sun, he is looking at plants.
The idea is to erect screen houses over crops to control light, using varying colors and meshes so each crop gets the optimum exposure to ultraviolet and infrared rays to produce maximum yields.
South Africa pioneered the approach 30 years ago and it has spread to Spain and Israel.
"Using shade cloth is old news for shade-loving plants like bromeliads, and during sunny parts of the year for other plants, but not to the degree of technology like these new things we're talking about, manipulating the color spectrum," says Rob Kluson, horticultural agent for the Sarasota County Cooperative Extension Service.
While shade cloth covers tens of thousands of square miles of agriculture in South Africa, solar radiation levels in Florida are lower. The correct mix of color and mesh differs for each crop.
And the finances must work; increased yields would have to be enough to offset the cloth system's costs.
That is where the experimentation comes in.
Through the Southwest Florida Small Farmer Network, Kluson and Connelly solicited volunteers to try the cloth, donated by Connelly's South African supplier.
My Mother's Garden, an organic grower in Wimauma, spread it over parsley and basil.
Kluson arranged the trial during the March to May growing season. He used three types of cloth — two white and one black and white — and one control group under direct sunlight.
The parsley under the cloth grew fuller and heavier than the control group; the basil showed marginal variation.
Even so, My Mother's Garden co-owner Kathy Oliver sounds like a TV commercial when she talks about the product.
"I was quite impressed with the cloth," she said. "It's lightweight, durable and easy to work with. We always used black shade cloth. It just cuts out the light altogether, all the wavelengths."
Oliver says she has to replace the covering on two 18-by-96-foot greenhouses. She plans to use the black and white Apollo Sunguard cloth, perhaps also experimenting with blues and reds, which affect photosynthesis.
At the Rosa Fiorelli Winery in Manatee County, owner Antonio Fiorelli reported similar mixed results after installing shade cloth in an 80-by-140-foot area over red and white grapevines.
Fiorelli says he noticed little difference in taste or sugar content, but that the vine and leaf growth under the cloth was more lush. The cloth went up in March, which captured only part of the growing season, so the vintner is not necessarily discouraged.
He says he plans to expand coverage to three acres next season.
Lynn Steward, owner of the 17-acre Mr. Citrus Organics and Vegetables farm in Arcadia, plans to try the cloth over lettuce, tomatoes, broccoli and cauliflower.
As he puts it, "Everything we do is a learning curve."
That is probably an appropriate description for Connelly's pilot work.
He has heard the claims. Now he wants to see if what works in Johannesburg will work in Sarasota. "We'll have to learn from real-world experience," Connelly says.
"I respect Kevin's go-slow approach," horticulturist Kluson notes. "People make a lot of claims for a lot of things in agriculture."
Kluson does not dismiss the potential, however. In October, he intends to present his findings from My Mother's Garden to the Gulf Coast Research and Education Center in Hillsborough County.
The center operates under the University of Florida's Institute of Food and Agricultural Sciences and if its researchers agree to study the effects of the shade cloth and its optimum usage, it will lend cachet to what is now a hopeful anecdote.