Promising horticultural crops for production in high tunnels in the mid-atlantic area of the United States

At The Pennsylvania State University High Tunnel Research and Education Facility located at the Horticulture Research Farm, Rock Springs, PA, there are twenty-eight (5.2 x 11.0 m) research high tunnel units. The Penn State high tunnels were designed so that the endwalls can be raised up to facilitate easy access into the tunnel for a small tractor, rototiller and other machinery. Since the inception of the high tunnel facility in the Fall of 1999, there have been many horticultural crops grown in the high tunnels including; many vegetables, small fruits, cut flowers, herbs, and tree fruits. Generally there are at least two crops and sometime three crops grown in each high tunnel per year depending on time to maturity of the crop and the crops optimum growing temperatures. Of these crops, the most promising in terms of economics were tomato (Lycopersicon lycopersicum), bell pepper (Capsicum annuum), garlic (Allium sativum), sweet Spanish onion (Allium cepa), red raspberry (Rubus idaeas), blackberries (Rubus allegheniensis) and cut flowers. Most insect problems in the high tunnel have been controlled with the release of biological organisms. There tend to be very few annual weeds in the tunnels, but it is important to control perennial weeds prior to establishing a crop in the high tunnels. The only serious disease problem that has been encountered in high tunnel crop production has been powdery mildew. Use of powdery mildew resistant varieties helps to control this disease in high tunnels.