Two 30’ x 96’ research high tunnels are part of a project to compare yields, fruit quality, nutrient uptake and disease levels in organic high tunnel and field production systems. High tunnels can give growers the ability to start crops earlier in the spring and grow them later in the fall. When used in conjunction with row covers, high tunnels can provide up to 15 degrees F protection at night, and tomatoes can be planted 30 days prior to typical frost-free dates without the use of energy-intensive furnaces. Another crop advantage of tunnels is protection from wind, rain and hail damage. Severe rainstorms in which several inches of rain fall in a day, or even over the course of several hours, damage plants and can cause severe fruit cracking. High tunnels offer protection from long periods of rainy weather and nighttime dew formation, conditions that encourage foliar diseases in field-grown crops. Since high tunnels act as rain shelters, workers have expanded opportunities for management and harvesting during inclement weather.
Another aspect of this research is to compare the productivity, nutrient uptake, and disease resistance of grafted and non-grafted heirloom tomatoes. Vegetable grafting is relatively new in American production, but widely practiced in Korea, Japan, other areas of Asia and the Mediterranean. Grafting is also becoming common in large commercial greenhouses. The purpose of grafting is to combine desirable traits from two different cultivars into a single plant. Usually the rootstock contributes resistance to specific soilborne diseases, and may also confer additional advantages, such as vigor, heat, cold and salinity tolerance and increased nutrient uptake efficiency. The scion, or top, contributes desirable fruit characteristics, such as size and flavor.
Grafting may be particularly promising for organic heirloom tomato growers. Heirloom cultivars are typically antique, open-pollinated lines, which are popular with consumers, but lack the disease resistances and vigor of modern hybrids. In 2007, ‘Cherokee Purple’, was used as the scion cultivar and a number of rootstocks were investigated in both tunnel and production systems. ‘Cherokee Purple’ has consistently been a favorite of customers at the Carrboro Farmers’ Market tomato tasting events. Each of these treatments will be replicated within the two tunnels and adjacent field plots. Further grafting research at the Small Farm Unit has been implemented to observe various rootstock combinations with four heirloom scions including: ‘Green Zebra’, ‘Yellow Brandywine’, ‘Pruden’s Purple’, and ‘German Johnson’.
give growers the ability to start crops earlier in the spring and grow them later in the fall. When used in conjunction with row covers, high tunnels can provide up to 15 degrees F protection at night, and tomatoes can be planted 30 days prior to typical frost-free dates without the use of energy-intensive furnaces. Another crop advantage of tunnels is protection from wind, rain and hail damage. Severe rainstorms in which several inches of rain fall in a day, or even over the course of several hours, damage plants and can cause severe fruit cracking. High tunnels offer protection from long periods of rainy weather and nighttime dew formation, conditions that encourage foliar diseases in field-grown crops. Since high tunnels act as rain shelters, workers have expanded opportunities for management and harvesting during inclement weather.
cultivars are typically antique, open-pollinated lines, which are popular with consumers, but lack the disease resistances and vigor of modern hybrids. In 2007, ‘Cherokee Purple’, was used as the scion cultivar and a number of rootstocks were investigated in both tunnel and production systems. ‘Cherokee Purple’ has consistently been a favorite of customers at the Carrboro Farmers’ Market tomato tasting events. Each of these treatments will be replicated within the two tunnels and adjacent field plots. Further grafting research at the Small Farm Unit has been implemented to observe various rootstock combinations with four heirloom scions including: ‘Green Zebra’, ‘Yellow Brandywine’, ‘Pruden’s Purple’, and ‘German Johnson’.