Factors to Consider

Climate and Elevation
Warm days, cool nights and low humidity generally produce higher quality grapes. The most consistent high quality has come from vineyards above 3,000 feet, one exception being Chardonnay with its susceptibility to spring frost. As elevation climbs, average temperature and humidity decline. Higher elevation provides lower temperatures during ripening, enabling grapes to ripen more slowly, develop flavor and retain the necessary acidity.

Elevation in the Hill Country ranges from approximately 800 to 1,800 feet; Fort Stockton, about 2,700 feet; Lubbock, over 3,000 feet; Fort Davis, 5,000 feet.

This is not to say quality fruit is not grown at lower elevations, but Texas weather presents big challenges. Stimulated by the heat, grapes grow rapidly, which can lead to early harvest and minimum "hang time," giving the fruit less time to develop flavor. Warm winters and rainfall in East, South and Central Texas can also create serious cultural problems. Rainfall can cause berry splitting and prohibit tractor and sprayer passage for fungicide protection. North Texas also has risks associated with higher rainfall.

High temperatures may limit sugar production and at night will increase respiration rates, causing the fruit's acid levels to fall rapidly. However, with proper management, most grapes can be ripened adequately.

Hot sun and summer heat does not usually damage grapes growing in the sun all season, but if grapes grown in canopy shade are suddenly exposed to sun, significant damage can result.

Areas with higher rainfall and humidity have serious problems growing grapes without significant applications of fungicides and pesticides. This is because leaf wetness encourages fungal diseases and insects tend to be more active in wetter areas.

Winter injury from freeze, frost or hail can severely damage crops. Frost can be especially damaging and is considered by some to have the greatest economic impact of any environmental factor on grape growing in Texas. Many growers are planting primarily red-fruited varieties, which generally break dormancy later than white grape varieties, leading to a reduced risk of spring frost damage.

Extreme low temperatures, especially when vines are not fully winter hardy, can cause vine damage or crop loss. While most wine grape varieties can survive undamaged below 0 degrees F when fully dormant during the winter, extreme changes in temperatures can leave vines less than hardy, possibly causing them to be injured at higher temperatures during the year's first freeze or a late spring frost.

Choosing A Site
Choosing the right site is crucial to a vineyard's success and is the greatest single decision a prospective grower can make. Because of the risk of Pierce's disease in certain parts of the state, this should be one of the primary considerations when choosing a growing location. If you meet certain criteria, including having a sound business plan, the Texas Department of Agriculture may be able to provide funding assistance through the Texas Agricultural Finance Authority. TAFA is a public authority within TDA that provides assistance to eligible creditworthy individuals and businesses through six financial assistance programs. Depending on the program, funds may assist with crop diversification, water conservation equipment and purchase of farmland. For more information call (800) TELL-TDA or (512) 475-1614.

Ideally, the site should be close to home. Long drives prevent optimum vineyard management. If planting grapes susceptible to Pierce's disease in an area at risk for the disease, you should clear a buffer zone of 150 feet or more around the vineyard to create an environment unfavorable to harmful insects, meaning you should be prepared to buy more land than you will plant.

Some other considerations: soil pH, drainage and structure; water volume and quality; rainfall; risks from hail, wind and disease; and marketing alternatives. Be sure to find out the likelihood of frost.

As long as soil is deep enough, a hillside or hilltop is superior to a low vineyard site. In spring, cold air drains to the lowest point. A vineyard on a slope has a better chance of surviving late spring frosts than one on flat ground or in a river bottom or depression.

Local county Extension agents can provide a county's fruit production history. The Natural Resources Conservation Service county office has information on soil types in the area.

Soil Requirements A soil sample should be collected and analyzed for pH before buying a site. Optimum soil pH is 6.5-7.5; acceptable soil pH is 6.0-8.0. Soils below 6.0 may require incorporating high volumes of lime before planting. Those above 8.0 have problems utilizing iron and zinc and have the potential for developing cotton root rot, one of the most destructive fungal plant organisms. Cotton root rot can attack more than 2,000 plant species, including grapes.

A soil analysis to determine nutritional deficiencies is also needed before planting. For a soil analysis, contact the Texas A& M University Soil, Water and Forage Testing Laboratory at (979) 845-4816. More information is available at the laboratory's website (http://soil-testing.tamu.edu). Private laboratories also provide soil analysis.

Grapes require well-drained, highly aerated soil at least 2 feet deep, and preferably 4 to 6 feet deep. Deep sandy loam with some gravel is recommended. Rocky soil is better than clay, though some clay soils are acceptable. Heavy clay is not suited to root growth. Uneven soil types can be a problem.

Surface drainage is important. Because vineyards are often "clean cultivated," significant soil erosion from rainfall may occur. Grapes like "dry feet." Water standing in a vineyard reduces oxygen, which can kill the plants.

"Cross-ripping" to a depth of 4 to 6 feet is the most beneficial single soil preparation, allowing grape roots to penetrate deeply. Cross-ripping may require a 6-foot ripping shank that disrupts physical barriers such as hardpan or thin rock layers. It is not necessary with deep, sandy loam soil.

Water Needs
Grapes require approximately 24 inches of rainfall or irrigation during the growing season. Sandy soils may need more. Clay soils have greater water-holding capacity and can be irrigated longer, but less frequently, than sandy soils. Extended dry spells, especially in June or July, make irrigation a necessity. Depending on depth and size, irrigation wells cost between $10,000 to $50,000. City water contains chloride and possibly sodium, ruling it out as the primary source of irrigation water.

Grapes return more dollars to growers per gallon of irrigation water than any other major crop in Texas. In Pecos County, for example, grapes require 2 acre-feet of irrigation water a year, while cotton requires 3 acre-feet and alfalfa up to 6 acre-feet.

Many irrigation systems are available, but drip is the most practical and widely used. Drip irrigation systems range from $1,000 to $2,000 per acre, depending on type, vine spacing and installation.

Grapes do not compete well for water and nutrients with grassy and broad-leaved weeds. Clean, cultivated vineyards will lower water consumption. In wet areas, a ground cover between grape rows may be necessary.

Chemicals
To grow grapes, Texas producers must fight a host of natural enemies. Growers in the eastern two-thirds of the state generally apply more chemicals to combat disease and insects than those in the western third, who use relatively small amounts. Applying regulated herbicides or state-limited-use or restricted-use pesticides requires obtaining a private applicator's license from TDA. For information, call (800) TELL-TDA or (512) 936-2638 or fax (512)463-1618.

Growing areas other than the High Plains and Trans-Pecos usually require more chemical input to control fungal diseases and limit Pierce's disease. Left unchecked, Pierce's disease can destroy a vineyard. Timely cultural practices such as removal of wild grape vines, immaculate weed control and establishing a weed-free perimeter around the vineyard will also help manage this disease.

Weed control is essential. Most annual weeds can be removed mechanically, but equipment is costly. Perennial grasses and weeds such as Nightshade can be removed with pre-and post-emergent herbicides.

Organic Production Disease risk makes large-scale organic cultivation of wine grapes difficult, if not impossible, in 95 percent of the state.

Diseases, Pests and Other Foes

Pierce's Disease: The most serious threat to wine grapes in Texas, California and other growing areas is Pierce's disease, which has caused millions of dollars in losses since the 1990s. Pierce's disease occurs in all areas of Texas that do not have severe winters and has attacked vineyards in every region but the South Plains. Before growers consider other crucial economic factors, they must understand the risk from Pierce's disease, which can wipe out a vineyard. Currently, there is no preventative or curative treatment for it.

Efforts to reduce the risk of Pierce's disease include controlling the glassy-winged sharpshooter and other xylem-feeding insects that spread the bacterium causing the disease. Site selection away from rivers, ponds and creeks, good habitat management and chemical control help prevent the pathogen's spread. Imidacloprid, a new chemical approved for use in Texas, has shown excellent results in control-ling glassy-winged sharpshooters when applied through a drip irrigation system. Vines pick up the chemical at the root, preventing harm to beneficial insects in the vineyard. Although a large research effort is underway to discover methods for controlling Pierce's disease, it will probably be a long time, perhaps 10 years or more by some estimates, before a practical, effective solution is available.

Fungi and Viruses:
Powdery mildew, downy mildew, black rot, cotton root rot and bunch rot are among the fungal diseases found in Texas vineyards. Powdery mildew occurs in all parts of Texas, but is more common in West Texas. Downy mildew prefers a cool, humid environment, thriving during a cool, wet spring or fall. It is prevalent in Southeast Texas and appears in other areas during extended periods of high humidity. Black rot thrives in areas of heat and high humidity including North, East, Southeast and Central Texas. Cotton root rot is significant in areas with high pH alkaline soils, such as Central Texas, but it is not a problem in East Texas or on the South Plains. Bunch rot can be a serious problem in any vineyard when rainfall occurs just before or during harvest.

Numerous viral diseases result in less vigor and productivity.

Pests Leafhoppers, flea beetles, grasshoppers, caterpillars, worms, nematodes, birds, rabbits, deer, raccoons, opossums, porcupines and many more pests like nothing better than a vineyard. Deer, rabbit and varmint-proof fencing is needed everywhere except the South Plains and parts of the Trans-Pecos. Growers should estimate $3.50 a linear foot to deer-proof a new site.

Labor Issues
Wine grapes are one of the most intensively managed crops, and most of the work is not done from the seat of a tractor. Growing grapes requires far more work and training than most people imagine.

A vineyard's first 2 to 3 years are especially labor-intensive and include planting and training vines. One full-time person is needed for 2 to 5 acres during this period. Afterwards, one full-time person can handle 20 to 30 acres, assuming the necessary equipment is available. Seasonal activities will require more workers and trained labor is costly and not always available. Depending on grape variety, hand-harvesting costs $75 to $400 a ton.

At large vineyards, mid-level supervisors oversee specific production areas or activities such as irrigation. They must have vineyard experience and training in pesticide use and other worker safety issues. Manual workers need job training and experience, as well as Worker Protection Standard and pesticide training. Equipment handlers require additional safety training.

Labor is the main reason many small vineyards have lower returns and why the trend is toward mechanization. But even mechanized vineyards require physical labor. For example, a High Plains grower with a 100-acre vineyard employs five full-time workers from February to mid-September.

A new mechanical harvester costs between $85,000 to $175,000 or more. Harvesters can also be rented from California. Several growers located nearby can also look into the possibility of pooling their resources to share equipment. Custom harvesting costs between $200-$ 300 or more an acre.

Education and Training
Training in wine grape production - viticulture - is vital for consistent grape quality and quantity. A vine-yard owner or manager should have field experience or formal education in wine grape production supplemented with continuing education.

Currently, viticulture classes are taught at Grayson County College in Denison. Texas Cooperative Extension agents also conduct educational events annually in several growing areas of the state. The Texas Wine and Grape Growers Association (TWGGA) plans to work with community colleges to develop more training programs and short courses. TWGGA also holds educational programs at its fall Harvest Festival and its February Grape Camp in Junction.

Some out-of-state training is also available, including distance learning via the Internet.

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