Apr 3, 2008
Southeast Drought Adds to the Woes of Fruit Growers There

The prolonged drought in the southeastern United States has had only a moderate impact on vegetable growers, who normally rely on irrigation to water their crops, but is hurting fruit growers.

Not only will continued drought threaten young trees, it will affect the ability of older trees to carry a crop. And the fruit set could be heavy this spring, following the freezes that wiped most of the fruit crop out last year.

“Virtually all the newer blueberry plantings are irrigated,” said Girard Krewer, University of Georgia fruit specialist in Tifton. “Older plantings that were not irrigated are suffering badly and some are already lost.”

In Georgia, much of the vegetable production is in the south, and fruit production there is mainly peaches and blueberries. Fruit growers in northern Georgia and across the Carolinas and Tennessee didn’t complain much about drought last year because freezes in early April took out a large portion of their grapes, peaches and apples.

Dave Lockwood, the University of Tennessee Extension fruit specialist with a shared position serving apple, grape and nut growers in east Tennessee and northern Georgia, said the drought in the mid-South and Southeast continues to get deeper, with no end in sight. North Georgia fell seven inches behind in 2006 and then 15 more in 2007.

Last year was an oddball, he said. Record high temperatures in March set the crop up for disaster when mid-teen temperatures came in April.

“It really worked over the crops,” he said. “They needed water to recover, and they didn’t get it. One of the better things was losing the crop because there was no water to support it. Fruit was just another stress on the trees. Young trees were hurt very badly.”

In an area where normal rainfall is usually 40 to 50 inches, growers have felt little need to irrigate. Sometimes drip irrigation is used to establish orchards or vineyards and some growers use overhead irrigation for frost protection, but irrigation is in not commonly used in fruit across the South.

Manage for moderate crop

Lockwood recommends that Southeastern growers manage their trees in preparation for a moderate crop load this year. Yes, they could use the income a big crop might deliver after losing the crop last year, but the water shortage might give more stress than the trees can handle. They might have to choose between saving the crop and saving the trees.

He suggested moderate pruning, moderate fertility and possibly heavier thinning this spring. In apples, a heavy bud set noted during late winter spring could put a lot of apples on the trees this spring, weather permitting, he said.

The freezes hit grapes hard last spring and the drought following didn’t help. Many roots lost their scion varieties completely and need to be regrafted.

In a year when a crop is lost to early freezes, other things can go wrong later. Given less incentive to protect the crop, growers may skimp on sprays, letting scab and mites do some damage to leaves. Low-functioning leaves, accompanied by drought, can set trees and vines up for further damage.

Lockwood is recommending growers be aggressive this spring, getting on copper and bactericides to prevent fire blight. Codling moth pressure may be higher this year, “so growers need to be aggressive on that,” he said.

Be aggressive, too, on ground cover management, he said. Weeds and grasses compete for water and, on frosty nights, add to the risk.

The area of drought covers Tennessee, part of Kentucky, much of the Carolinas, eastern Alabama and Georgia, Lockwood said. Some areas received fair rains during the winter.

But the outlook is for continuation of the La Nina pattern, which brings higher than usual temperatures and lower than usual rainfall to the southeast.

“We need rainfall, more than anything else,” Lockwood said.

Pam Knox, the assistant state climatologist for Georgia, said that southern Georgia sits atop the Floridan aquifer, which contains a “fairly inexhaustible” supply of water that is close to the surface and easy to access. Since water in the state flows south, there is more in the watershed further south.

The major fruit production area is further north, where the water supply situation is quite different. The area around Atlanta and in northwest Georgia is highly dependent on rainfall, captured in reservoirs and manmade lakes like Lake Lanier, which supplies fresh water to the booming Atlanta metropolitan area.

On the national drought monitor, Knox said, northwest Georgia is in a D-4 drought, the worst category, corresponding to a once or twice in a century occurrence. In the last two years, the area has had a rainfall deficit of about 17 inches.

For vegetable growers who irrigate, drought in not as big a problem.

“Growers like enough rain to keep wells and ponds full, but not so much that it creates disease and other problems,” said Terry Kelley, University of Georgia Extension vegetable specialist in Tifton, Ga. “Growers like to see it on the drier side. They get a better quality crop.

“Part of what makes Georgia a good place to grow vegetables is the abundance of aquifers with good water,” he said. “Now, if ponds and wells go dry, that’s another hurdle.”

Rainfall this winter recharged ponds so they looked pretty good going into spring, he said.

Saving gray water

One indicator of the shortage of water can be seen in new advice for homeowners coming from the University of Georgia.

They are working on ways to reuse gray water collected from showers, baths, sinks and washing machines for use to flush toilets, water yards and gardens and conserve water. While not significant for commercial horticulture operations, gray water can be directed into drip irrigation systems and used to save trees and shrubs.

When the drought and subsequent water bans sent gardens and lawns from green to dead, Georgians’ interest in reusing water on their landscapes spiked.

Frank Henning, a University of Georgia Extension watershed agent, is working with other faculty members and north Georgia governments to guide Georgians on how to safely and legally install and use gray water recycling systems in their homes, particularly to flush toilets. Their work is meant as a model for counties considering code changes.

The gray water advisory group has discussed safety features for recycling systems, such as backflow prevention, purple pipes and dye injection units to separate gray water from drinking water physically and visually.
David Stooksbury, Georgia’s state climatologist located at the University of Georgia, said winter rains were a welcome sight for Georgians tired of dealing with the drought that started in March 2006.

Unfortunately, drought conditions persist across much of the state, and will likely continue, he said as winter was ending.

The area north and west of the Chattahoochee River is in exceptional drought. The river, one of two that runs into Lake Lanier and provides drinking water to Atlanta, was running at from 34 to 44 percent of its normal rate. The Chesatee River, the other major river that supplies water to Lake Lanier, was flowing at 40 percent of its normal rate.

“The outlook isn’t promising,” Stooksbury said. “There is still a very good probability that drought conditions will intensify. Thanks to a moderate to strong La Nina climate pattern, there is a high probability that Georgia will experience temperatures above normal and rainfall below normal through spring.

“There is concern Georgia will not receive enough rain this winter and spring to cushion us this summer. If we do not receive enough rain, we may need strong conservation efforts in summer to protect the water supply.”




Current Issue

On-farm AI: Water, farm, labor research guide decisions

Data collection tool expands farm management

Carmel Valley winegrapes: Parsonage Village Vineyard

IFTA Yakima Valley tour provides orchard insights

IFTA recognizes tree fruit honorees

Pennsylvania recognizes fruit industry professionals

Fresh Views 40 Under 40

see all current issue »

Be sure to check out our other specialty agriculture brands

produceprocessingsm Organic Grower