Sunbelt Expo Field Day combines old, new ag trials

30 Aug Sunbelt Expo Field Day combines old, new ag trials

Posted August 13, 2012 in Southeast Farm Press

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With more than 40 stops, this year’s Sunbelt Ag Expo Field Day offered a jam-packed tour of the very latest in cutting-edge technology along with long-running production and variety trials.

The field day offers a preview of what can be seen at this year’s 35th Sunbelt Ag Expo, set for Oct. 16-18.

About 400 people rode trams into the fields of the Darrell Williams Research Farm in Moultrie, Ga., to hear agricultural company representatives and University of Georgia researchers present their latest findings.

New to the Expo site this year was a melon and cotton intercropping system initiated by Brian Tankersley, Tift County, Ga., Extension coordinator.

The system, which has been tested in other locations since 2010, aims to improve profits for spring vegetable producers by planting cotton alongside curcubits like cantaloupes and watermelons.

At the Expo site, cantaloupes and watermelons were transplanted into fields between March 18 and April 25. Between April 18 and May 25, herbicide-resistant cotton was then seeded in between the melon plants.

After the melons were ready for harvest, herbicide was sprayed to burn down the remaining curcubit vegetation, leaving the cotton to mature for the rest of the growing season.

Tankersley says that previous research with five growers on 385 acres revealed that cantaloupe and watermelon yields were comparable to the yields of those same crops when grown alone. Melon harvest did not damage young cotton plants, and cotton planting did not delay melon harvest.

In several locations, cotton yielded more than 1,100 pounds per acre in later plantings after July 10. Also, economic returns and profitability of cotton compared to late-planted grain sorghum is very positive toward cotton inter-cropping, reports Tankersley.

Researchers continue to evaluate weed control management and pesticide compatibility issues.

Also at Field Day, University of Georgia Extension Forage Specialist Dennis Hancock discussed the benefits of interseeding alfalfa in bermudagrass.

The system, he says, allows farmers to grow their own nitrogen and increase the quality of their forage by 30 or more RFQ points. It also makes an excellent supplemental feed and/or cash hay crop.

Alfalfa, he explains, fixes nitrogen and virtually eliminates the cost of purchasing additional nitrogen fertilizer. In addition, growing alongside bermudagrass helps alfalfa dry faster, allowing it to be harvested more cleanly.

“Growers need to select a well-drained site for planting,” says Hancock. “Soil-test the site and lime and fertilize according to recommendations. The ideal pH level for the combination of bermudagrass and alfalfa is 6.5.”

Hancock stresses the need to follow fertility recommendations for potassium, with concentrations of 250 to 300 pounds per acre. The micronutrients boron and molybdenum should also be present for nitrogen fixation.

The ideal planting time for the Coastal Plains region, he says, is Oct. 15 to Nov. 15, and berumdagrass should be very short when planting. He advises planting with a no-till drill at a seeding rate of 22 to 25 pounds per acre in 7 to 9-inch rows. Plantings should be no deeper than one-half inch.

Irrigate if possible

After emergence, Hancock says to spray with an insecticide to control mole crickets and other insect pests, and to irrigate if possible.

Growers also should scout and spray for alfalfa weevils in February and March and fall armyworms during the summer.

University of Georgia researchers have developed an alfalfa variety — Bulldog 805 — that tolerates grazing, has excellent hay yields, and is adapted for the Coastal Plain region. It also has high pest and disease resistance.

While the results at the Expo site this year have not been what was hoped for, researchers will continue to work on a system for growing organic peanuts, says Carroll Johnson, USDA-ARS.

“Last year in Tifton, we had two acres planted to organic peanuts, three varieties, one fungicide application of copper and sulfur, eight cultivations with specialized equipment, and one very quick, cursory hand weeding, and we yielded more than 5,000 pounds per acre. But everything lined up just right last year. Nothing has worked for us this year,” says Johnson.

“But this is real-world, and we’re sticking with it,” he adds.

The real missing link in making organic peanuts a viable enterprise on Georgia farms is having someone to process them and maintain the integrity of the organic certification, he says.

“The majority of organic peanut butter in the U.S. goes to California, and that’s from one farming operation in west Texas and eastern New Mexico. They grow Valencia peanuts, which has about half the potential of what we grow here.

“We can do it better in Georgia. We can grow them here and we can do it better. We need to close the circle — we need someone to buy them, shell them, blanch them, and roast them,” says Johnson.

Stand establishment and seed quality is a problem in organic production, he says, and there aren’t any good seed treatments. “You have to plant in good conditions and have good seed to begin with. Marginal quality seed will betray you in organics.”

Researchers with the University of Georgia Peanut Team continue to evaluate different cultivars in various planting systems at the Expo site. They’re currently looking at eight runner-type varieties in single and twin-row planting patterns. Five are currently available to growers while three are newly released.

This is a duplication location of a test we’ve been running in Tifton for several years on tillage versus cultivar versus row pattern,” says John Paulk, research coordinator.

“We initiated this test in November of last year. We mowed cotton stalks, disked them and planted wheat. We killed the wheat in late March and started harrowing for our conventional-tillage part of the test. On April 11, we laid off rows and strip-tilled on the same day,” he says.

Peanuts at the Expo were planted on April 16, says Paulk, and followed with an application of Prowl, Valor, Strongarm and Dual.

Hot mix

“It’s a hot mix, but we have not pulled any weeds. We followed that on June 13 with Basagran and Dual. We’re following a standard fungicide program on these peanuts. It’s critical that we continue to update our research on new varieties,” he says.

Also at Field Day, members of the UGA Cotton Team reported on their long-term fertility, insect and agronomy trials.

“Potassium on cotton continues to be a big issue,” says soil fertility specialist Glen Harris. “We’re looking at split applications of potassium and foliar applications, early and late, on six varieties.

“Last year, the varieties did seem to react differently between early and late foliar applications, so we’re trying to see if that’ll happen again. We’re also looking at a lot of different nitrogen materials,” he says.

Extension entomologist Phillip Roberts says most of his efforts at Expo are efficacy trials to compare different insecticides on whichever pest might be present at the time.

“We have thresholds for all our common pests, and we want to advise growers on what’ll do a good job for them. In addition to looking at the effect on target pests, we also look at the impact on beneficial insects or how a certain pesticide is likely to flare another pest.

“We know that insecticide selection can cause a certain pest to be more of a problem. We encourage our scouts to be aware of uncommon pests as well as the more common ones,” says Roberts.

Agronomist Guy Collins says he’s trying to identify the cotton varieties that perform consistently in the top. “We also want to learn how to better manage these new varieties. Some are earlier maturing than DPL 555. We’re also looking at irrigation and its effect on different varieties. We’re learning how to position these varieties.”