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  • Author or Editor: Conrad J. Weiser x
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Abstract

The threat of economic losses due to frost injury is present in almost every region of the world where potatoes are cultivated. Frost damage to foliage is particularly important in parts of South America where potatoes are a primary dietary staple, but losses are also significant in many regions of North America, Asia, Northern Europe and the USSR. Potatoes are commonly grown in the temperate regions and at high elevations in the tropics where frost is a chronic problem. A particularly harsh frost in Colombia, in 1967 caused an estimated $50 million loss. Fortunately many growers in the Andean region plant small insurance crops of wild-type potatoes which possess substantial frost resistance, although the the yield and quality is poor.

Open Access

Abstract

Effects of temperature on cold acclimation and deacclimation of red-osier dogwood (Cornus sericea L. syn. Cornus stolonifera Michx.) plants were determined at different stages of plant development. Results were used to develop models for predicting stem hardiness. Acclimation and deacclimation rates were related to temperature and plant developmental stage (expressed as degree growth stage, °GS). Decreasing temperature promoted increasing acclimation. Maximum acclimation rates in the temperature range of 5° to 20°C occurred at maximum rest (270°GS). During the decreasing rest phase (270 to 315°GS), deacclimation occurred at temperatures from 7° to 20°C. At earlier stages of development (315° and 335°GS) during the quiescent phase (315 to 360°GS), 5°C was the only temperature that promoted hardiness, whereas at a later stage (341°GS) all temperatures tested caused deacclimation. The models, using bihourly temperatures and accumulating °GS, predicted hardiness within an average deviation of 4.7°C.

Open Access