Drought and extreme heat were weighing heavily on the minds of the 450 farmers and others who braved soaring temperatures to view the latest in agricultural research at the Sunbelt Ag Expo Field Day, held recently in Moultrie, Ga.
Dry weather conditions and temperatures in the 95-degree-plus range have been prevalent in the lower Southeast this summer, and the Expo's 550 acres of crops have been no exception. “It has been extremely dry for us this year,” says Darrell Williams, Sunbelt Ag Expo farm manager. “This is a big change from the previous two years, when we received good rainfall.”
As a comparison, Williams says the Expo site received about 20 inches of rain in May and June of 2006, while it has received only 5 inches this year during the same two-month period. “I used to say the dry weather didn't bother us so much here because we can water all of our crops and control the amount of moisture, but the rising cost of diesel has just about changed my mind on that,” he says.
Those attending this year's Expo Field Day got the opportunity to view traditional variety and yield testing for cotton, peanuts, corn, soybeans and grain sorghum, in addition to various other plot work and cutting-edge technologies.
University of Georgia Extension specialists and researchers are using the Expo site this year to look at the effects of various planting dates on peanuts. “One of the most important aspects of our work is to stay accurate with our recommendations in the Tomato Spotted Wilt Virus Risk Index,” says John Paulk, University of Georgia research assistant. “We're looking at six varieties — Georgia Green, AP-3, Georgia-03L, C-99R, Georgia-01R and Georgia-02C — planted at different times to determine if we can possibly plant earlier than the typical optimal window in the index.”
Researchers will be collecting yield data this year from 17 peanut varieties, says Paulk. Included in these are some newer ones from Florida such as McCloud, York and Fla.-07 or “Lucky Seven.” “It's being called Lucky Seven because it has consistently produced 7,000 pounds of peanuts per acre, and it has good resistance to tomato spotted wilt virus,” he says.
University of Georgia Research Entomologist Jim Todd is looking at incorporating new sources of disease resistance into peanut varieties. One new variety — Attaboy — has resistance to tomato spotted wilt virus, leafspot, white mold and other diseases.
Todd also warned growers that during a dry year, insects can cause damage to peanuts. “Unfortunately, it looks a though it's a bad year for soil moisture. Lesser cornstalk borer is a dry-year pest that we need to be looking for. It isn't as much of a problem as it once was because so many of our peanuts are irrigated, but you need to scout for it and make sure you don't get into a bad situation,” says Todd.
Spider mites are a late-season insect pest that still can reduce peanut yields, he says. “When you combine insect problems with the other stresses of a dry year, there's no margin for error.”
Conservation-tillage plots also are being featured at Sunbelt Ag Expo, and researchers with Team Conservation-Tillage are looking at the fuel savings that can be gained from such practices.
Ben Moore with the Natural Resources Conservation Service says farm surveys and studies have shown significant fuel savings with conservation-tillage. One study looked at a 1,000-acre farm with a three-year crop rotation of corn, cotton and peanuts. A conventional-tillage system with no cover crop required 19 field operations at $10 per acre per year or $10,000 at a fuel cost of $2.23 per gallon.
A strip-tillage system with a cover crop required 13 field operations at $5 per acre per year or $5,000 at a fuel cost of $2.23 per gallon. These costs did not include harvest or pest management.
Savings can vary significantly based on the size of the farm and the number of field operations, says Moore, but a survey of farms has shown that on a 1,000-acre farm, 6,300 gallons of fuel will be used in a conventional system versus 2,400 gallons in a conservation-tillage system. The average savings — including equipment, fuel and labor — from using conservation-tillage can range from $13 to $60 per acre.
The University of Georgia Extension Cotton Team has about 26 studies at the Sunbelt Ag Expo site this year, says Cotton Specialist Steve M. Brown, including one looking at the new plant growth regulator Stance. The new product features a simple rate of 2 to 3 ounces per acre, he says.
Taking into consideration the rising cost of nitrogen, cotton researchers also are looking at the rates and timing of nitrogen applications, including split applications — preplant, sidedress and foliar, says Glen Harris, Extension soil scientist.
“With the rising cost of nitrogen, we're also seeing a shift from ammonium nitrate to urea. The issue with urea is that it has inhibitors that keep down volatilization, so we're taking a closer look at that. We're also looking at manganese to see if it might help with cotton uniformity,” says Harris.
The Expo site is part of a regional stink bug trial that is refining treatment options for the pest, says Phillip Roberts, Extension entomologist. “We're applying controls at various times to determine the critical window for controlling stink bugs. We're also refining our treatment thresholds,” he says.
Extension weed scientist Stanley Culpepper talked about weeds that are becoming increasingly troublesome for Georgia cotton producers — tropical spiderwort and Palmer amaranth pigweed. “Tropical spiderwort is having its way with us. We're looking at 70 different herbicide systems to determine the best control for this weed. It'll cost us at least one-third more and 50 percent more in some cases to control tropical spiderwort. This weed might take some of our growers out of conservation-tillage, since the moldboard plow seems to be one our best treatments,” he says.
Palmer amaranth pigweed, says Culpepper, can grow up to 2 inches per day and produces both male and female plants. “This plant is glyphosate resistant, and no one in the state of Georgia is safe from it. It could double our weed management costs or increase them by as much as two and a half times. Some of our fields won't be picked this year because of this weed,” he says.
Phil Howard of Southern States Cooperative is working with former University of Georgia Extension Soybean Specialist John Woodruff at the Expo to test an early planted, early maturing soybean system. The 10-acre test compares early maturing Zone 4 and 5 soybean varieties to more traditional Zone 6, 7 and 8 varieties.