• High tunnel production of lettuce (Lactuca sativa) and snap beans (Phaseolus vulgaris l.) in a High Latitude location

      Rader, Heidi B.; Karlsson, Meriam; Zhang, Mingchu; Smeenk, Jeffrey (University of Alaska Fairbanks, 2006-12)
      Fairbanks, Alaska (lat. 64°49’N) has a short, variable growing season which necessitates alternative growing techniques for reliable vegetable production. Air and soil temperatures, relative humidity, light penetration, and management requirements were evaluated for a double bay high tunnel [15.8 m wide × 3.7 m high × 14.6 m long]. Mean air temperature was 0.5 °C and soil 1.2 °C higher in the high tunnel than the adjacent field, but differences varied with ventilation and heating practices. Yield and growth characteristics of lettuce (Lactuca sativa: ‘Paris Island cos’ and ‘Two Star’) and snap beans (Phaseolus vulgaris L.: ‘Concesa’ and ‘Provider’) were evaluated. Lettuce was frost hardy in the open field, prone to bolting in the high tunnel, and in general did not benefit from the high tunnel environment, except in quality due to cleanliness. ‘Concesa’ produced significantly more in the high tunnel compared with the field (P < 0.005). ‘Provider’, produced more in the high tunnel in 2006 compared to the field, but differences were not statistically significant over two seasons. The perceived benefits of high tunnel production included protection from frost, wind, pest, and rain, improved yields depending on crop and cultivar, and decreased weed emergence and moisture accumulation.