2017 ASHS Annual Conference

Frost can have a devastating impact on potato production since most cultivated potatoes are very sensitive to frost and are severely damaged at air temperatures below -2 or -3 C. In the Altiplano of Peru and Bolivia over 60,000 hectares of potato production is impacted by frost. It has been estimated that in this area potato production can be increased by 40% by simply increasing frost tolerance by 1-2 C. At present over 60% of the frost prone areas are planted with bitter but frost hardy potatoes. Similarly in many areas of China and India, winter crop can be severely impacted by frost. In the global climate change scenario frosts are predicted to be more erratic and severe. This is already happening in the Altiplano. For example in mid-January of 2015 air temperature dropped to -3C creating a severe foliage damage to cultivated potatoes. Mid-January is mid-summer season for these areas and thus peak growing season. Over the last two decades we have taken a systematic approach to developing frost tolerant potatoes. During a natural frost, ice is produced extracellularly. This results in cellular desiccation and mechanical stress to the leaf tissue. Frost hardy species such as S. acaule and S. commersonii survive by tolerating the stresses induced by extracellular ice. We have used these two species as of source of frost hardiness to select commercial type cultivated clones. Some of these clones are hardy to -5C after cold acclimation. Using similar strategy we are making some progress in moving frost tolerance to native potatoes cultivated in the Peruvian Highlands. These studies demonstrate that there is potential for developing commercially desired cultivars with improved tolerance to frost.