Apple production potential in Interior Alaska within a state of amplified climatic change

Abstract

Successful apple (Malus Domestica) tree and fruit growing have been ongoing in Alaska for over 100 years. At the outset, crabapples were the only varieties produced, but as agriculturalists, orchardists, and farmers began to experiment with grafting coldhardy rootstock with scions, new cultivars began to emerge, with varying degrees of success, throughout the state. In addition to experimental cultivars, the climate began to change, with an overall warming trend emerging. Together these variables could be the winning combination to large-scale apple orchards being started in the state of Alaska. More fruit production in the state would strengthen both the small agricultural industry and the state’s food security posture. If raw fruit products can be produced, then possibly other related business and commerce will become possible, such as production of apple cider, apple sauce, fruit leather, and preserves. The state of Washington, particularly the Eastern side, has prime apple-growing weather and climate. Of all the states, Washington produces the most apples annually. The national top ten most consumed apples are grown there. The Eastern Washington climatic region was chosen for comparison and a point of reference versus the projected interior Alaska region climate. Long-season, later-harvest apples are grown in Eastern Washington, but not in Alaska. This type of apple is valuable and desirable due to its potential for stable, long-term storage. Currently, Alaska-grown apples can be of high quality but are smaller to medium-sized, in general, and not conducive to long-term storage. Long-term storage compatible apples are desirable because that trait makes year-round apple eating possible. The purpose of this research project is to evaluate whether longer growing seasons, due to climate change, will potentially allow production, in interior Alaska, of late season apples. The analysis approach includes a combination of personal observations, literature review, climatic modeling, evaluation, and synthesis of data from multiple sources. Climatic trends and data from both past and future years were examined. Environmental variables such as atmospheric temperatures, precipitation, first and last frost dates, plant hardiness zones, and growing degree days were included in the analysis. It was found that within the next two to three decades, or sooner, with some model predictions, that the interior Alaska climate will be approaching that of Eastern Washington, although still cooler in both the winter and summer. Nevertheless, hardiness zone compatibility indicates that interior Alaska will have a climate that is conducive to growing both the shorter season apples (generally used for cider) and later-harvest, long-term storage apple varieties (mainly used for direct consumption). Interior Alaska average annual air temperatures have been slowly but steadily climbing over time, with increases evident year-round. Precipitation has also been found to be increasing, with rain in some locations during the winter (where previously there was no rainfall) melting the snow and affecting the snow coverage of an area. Rainfall has been increasing in the shoulder seasons too, affecting the growing season. Evapotranspiration has also been projected to increase, potentially nullifying the benefit of increased precipitation for natural crop irrigation purposes. With permafrost also degrading statewide, soil conditions may naturally get drier. Irrigation and on-farm water storage may prove to be a short-term method to overcome more arid environmental conditions.