|Flue-Cured Energy Efficiency Program|
|Black Shank and Granville Wilt Resistant Varieties|
|Blue Mold Forecast|
|Tobacco Cyst Nematode|
|Tobacco Mosaic Virus|
Greenhouse Transplant Production
|Media Testing Float Greenhouse|
|Production Guides and Variety Bulletins|
Alfalfa Variety Trial
Alfalfa is often call the "Queen of Forages" and is the most important forage legume in the United States. It possesses the highest nutritive value of all commonly grown forage plants. In Virginia, alfalfa is grown on more than 1.15 million acres. Although alfalfa is commonly thought of as hay, it can also be an important component of pasture swards. Virginia Tech’s Alfalfa Variety Trials tests commercially available varieties at three locations in Virginia. The best varieties will perform well at all locations.
Bermudagrass is commonly considered a weed due to its prolific growth habit. However, bermudagrass has the potential to provide reliable summer pasture. It is drought tolerant, high yielding, responsive to nitrogen fertilization, and tolerant of close and frequent grazing. Bermudagrass hybrids must be established from sprigs (plant parts). This has limited bermudagrass use in Virginia. Recent development of seeded forage bermudagrasses may provide a viable alternative for producers in Virginia. On going research at the Southern Piedmont AREC is evaluating the yield, nutritive value, and persistence of both sprigged and seeded bermudagrasses.
Crabgrass is a warm-season species that is well adapted to southside Virginia. It is commonly considered a weed due to its prolific growth habit. In other regions of the country, improved crabgrass routinely produces between 4,000 and 10,000 lb DM/A. Crabgrass is very palatable and possesses a high digestibility and protein concentration when compared to other warm-season grasses. Little is known about the performance and management of improved crabgrass in Virginia. Research has been initiated at Virginia Tech?s Southern Piedmont AREC to evaluate the performance of improved crabgrass and establish management guidelines.
Small Grain Silage
In Virginia, 200,000 acres of corn were harvested as silage in 1999 (Virginia Agricultural Statistics Service, 2000). In the southeastern United States, the time of the year that corn is grown does not have consistent rainfall. This results in large year to year variation in corn silage yield. In contrast, small grain growth is not normally limited by moisture and therefore has the potential to provide a reliable alternative to corn based silage systems. Research is being conducted at the Southern Piedmont AREC to evaluate production of silage systems based on small grains followed by four warm-season annuals which include corn, sorghum, soybean, and crabgrass.
Research from the Midwestern United States has shown that corn can provide grazing in late summer, allowing for stockpiling of cool-season grasses. It may also be possible to stockpile standing corn for deferred grazing during the winter months. This could reduce hay needs and fill in the gap between stockpiled tall fescue and new growth in the spring. A study currently underway at the Southern Piedmont AREC will track the yield and quality of standing corn and sorghum from September to March.
Corn Silage Variety Trial
Corn harvested as silage plays an important role in providing the energy requirements of more than 119,000 dairy cows in Virginia. In 1999, more than 200,000 acres of corn were harvested as silage (Virginia Agricultural Statistics Service, 2000). Virginia Tech’s Corn Silage Hybrid Evaluation Program provides unbiased estimates of yield and forage quality of commercially available corn hybrids. In 2001, corn silage hybrids are being tested at three locations in Virginia one of which is the Southern Piedmont AREC.
Strawberries are produced using the plasticulture system in Virginia. This has been adopted due to the high productivity and consumer preference for picking on plastic. The two most critical factors affecting the productivity and economics of the sytem are planting date and choice of cultivar. Cultivars are selected to either fill a season gap, marketing niche, or on total season yield. Early planting resulted in an increase in unmarketable yields, smaller fruit size, and less sugar compared to the optimum planting date.
Teenage workers smeared a Project Leader's blue Ford with purple raspberries to express their feelings about harvest conditions in our 'V-trellised' research plots in 1988. The crop-load was very heavy and most of it was located between 2 curtains of leafy floricanes (as were the fast-growing, prickly primocanes). We understood the workers' frustrations and began research on ways to improve harvestibility of bramble crops. The Single-Sided Shift-Trellis (SSST) and the Limited Arm-Rotation System (LARS) are now available to manage plant canopies so that their fruits are displayed in a highly visible and easily accessible zone on a single side of the trellis. Isolation and open display of the fruiting zone allows harvesters to quickly identify and gather ripe fruits. Thus, harvesting speed, timeliness, and thoroughness all may be improved by use of SSST or LARS. These systems' effects upon plant canopy structure can also protect berries from sunscald, reduce heat load in harvested berries, increase air movement around plant parts, increase the exposure of young primocanes to sunlight, and improve the targeting of pesticide sprays. Such effects should greatly improve the feasibility of "organic production" and increase the efficacy of Integrated Pest Management (IPM) in these crops. Improved harvesting conditions should also increase customer satisfaction (and sales volume) among "U-Pick" bramble enterprises.
Our newest canopy management system (with a Modified LARS trellis) is being demonstrated and refined in the raspberry/fabric mulch study. This system features a simpler structural design, fewer materials, and it eleminates certain constructions tasks. Although SSST, LARS, and Modified LARS trellises initially are more expensive than standard trellises, their net economic impacts should be calculated to include reductions in: harvest costs; cullage; pre-cooling energy expenditures; and pesticide costs. Partial mechanization of certain pruning tasks, and reductions or re-distributions of other pruning labor, may further increase the net value of these trellises.
Three-year-old potted plants of rabbiteye (Premier, Powderblue, and Tifblue) and 2 northern highbush (Bluechip and Harrison) cultivars were transplanted to wide, 18" tall, raised beds during 1983. Soil was fumigated with Vorlex and pH was adjusted by incorporation of sulfur and well-rotted sawdust in 4'-wide strips throughout each bed's length. Rows were spaced at 10' on centers; rabbiteye transplants were spaced at 6' and highbush at 4' within the row. All cultivars were harvested during 1987, 1988, 1989, and 1993. Rabbiteyes were harvested also during 1995, 1996, and 1997. No winter injuries of stems or twig tissues have been observed in any of these cultivars to the present date (15 winter seasons), but late winter freezes and spring frosts have been associated with injuries of current seasons growth and flower blossoms in some years. The latter injuries appeared to be no more serious in rabbiteye than in highbush cultivars during any year. Fungicides (except lime-sulfur in March 1997) have not been employed since 1993, and since that time, mummyberry disease has become so prevalent among highbush fruits that harvests of Bluechip and Harrison were discontinued during the latter three observation years. Mummyberry was not evident among fruits of the three rabbiteye cultivars. Harvest seasons of mature rabbiteye cultivars were longer and later, and yields were higher, than those of the 2 northern highbush cultivars, so direct-marketers probably should consider both types for production in this area.
The climatic uniqueness of the southern and eastern Piedmont regions warrants specific cultivar evaluations to support existing and potential grape and wine producers in this region. Southern Virginia and northern Piedmont region of North Carolina have warmer day and night temperatures and receive greater precipitation. A wine grape cultivar evaluation was established at Virginia Tech?s Southern Piedmont Agricultural Research and Extension Center in spring 2001. Plantings consist of three-vine plots replicated six times in a randomized complete block design. Drip irrigation and deer exclusion fencing were installed. Vines and vineyard will be managed following commercially recommended practices. Cultivars being evaluated include Vidal, Traminette, Norton, Tannat#1, Mourvedre, Viognier#1, Rousanne#1, Cabernet Sauvignon#7, Cabernet Sauvignon#337, Chardonnay#96, Tempranillo, Petit Manseng, Touriga nacionale, Tinta cao, Aleatico, and Muscat. Cultivar rationale is based on favorable performance at Winchester (Petit Manseng, Mourvedre, Vidal, Viognier, Cabernet Sauvignon), a late-bud characteristic (Vidal, Cabernet, Tannat, Mourvedre), pronounced aromas or flavors that may persist under less than optimal ripening conditions (Muscat blanc, Petit Manseng), limited but favorable commercial experience (Norton, Tinta cao, Touriga), or a combination of these reasons. Data collection will begin in 2003 and wines will be made in the Food Services and Technology Department at Blacksburg.
|VAES Bulletin 99-1||Limited Arm-Rotation Shift-Trellis (LARS) and Primocane Management Apparatus (PMA) for Raspberries and Blackberries (Rubus cvs. or crops)||H.D. Stiles|
|VAES Bulletin 95-2||Shift-Trellises for Better Management of Brambles (Rubus cvs.)||H.D. Stiles|