UNH Researchers Produce Overwintered Onions in Low Tunnels
University of New Hampshire researchers have grown bulbing onions with the aid of inexpensive low tunnels. The onions, which were planted in fall for a spring harvest, were grown in response to a high demand for year-round local produce. New Hampshire Agricultural Experiment Station (NHAES) faculty researcher, Becky Sideman, extension professor of sustainable horticulture production at UNH and her colleagues presented their research findings in the December issue of HortTechnology. The researchers evaluated the survival, bolting and bulbing of several cultivars of fall-planted onions in two sites in New Hampshire over two growing seasons. Plants were seeded in August and September, and transplanted in September and October into raised beds covered with black plastic mulch. Low tunnels were installed over the plants in late fall and onions were harvested from mid-April to early June 2012 and late May to early July 2013. Study findings showed high percentages of survival in all onion cultivars (between 65 and 100 percent). Onions that were planted later exhibited lower percentages of bolting and smaller bulbs at harvest. Researchers concluded that cultivar selections play a crucial role in successful overwintering of onion production systems in cold climates. The research was funded by the NHAES and Northeast SARE. For more information, visit www.unh.edu.
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