Summary of Vegetable Variety Trials, Fairbanks, Alaska, 1978-1985

Abstract

Selection of the appropriate cultivar (cultivated variety, referred to as a variety hereafter) is a major factor in determining the success or failure of that crop for commercial growers and home gardeners. Plant breeding has brought about vast improvements in crop productivity by incorporating disease resistance, increased yield potential and environmental adaptability into new varieties. Because the environment and growing season in Interior Alaska are much different from most other agricultural regions, it is difficult to predict how a new variety will perform here without actual testing. For instance, the long hours of daylight during the growing season are used to advantage by such varieties as O–S Cross cabbage and Shogun broccoli, which grow to extremely large size. However, long days may cause some varieties of crops such as radishes, beets, spinach, carrots, cauliflower and Chinese cabbage to bolt (form flower stalks) before forming a usable product. Long days may delay fruiting with some varieties of winter squash and melons.

Another important aspect of the climate is the amount of heat received during the growing season (approximately 90 frost–free days in Fairbanks). Many varieties of warm–season crops such as sweet corn, tomatoes, peppers, and melons may not mature here because insufficient heat is accumulated during the growing season, even though the growing season is potentially long enough. The use of cultural techniques such as clear polyethylene row covers to increase air temperatures may enable adapted varieties to reach maturity.

Soil temperature is another important factor in the adaptability of vegetable varieties to our climate. The relatively cool soil temperatures (reaching a maximum of 70 degrees Fahrenheit) are adequate for good growth with cool–season crops (in general, crops where the stems, leaves, immature flower buds or roots are eaten — for example, broccoli, lettuce and carrots), but severely limit the growth of warm–season crops (crops where, in general, the fruit is eaten). With cultural techniques such as use of clear plastic mulch to raise soil temperatures, and the use of adapted varieties, many warm–season crops can be grown here.