Spring frost vulnerability of sweet cherries under controlled conditions

Abstract

Spring frost is a significant production hazard in nearly all temperate fruit-growing regions. Sweet cherries are among the first fruit varieties starting their development in spring and therefore highly susceptible to late frost. Temperatures at which injuries are likely to occur are widely published, but their origin and determination methods are not well documented. In this study, a standardized method was used to investigate critical frost temperatures for the sweet cherry cultivar 'Summit' under controlled conditions. Twigs were sampled at four development stages ("side green," "green tip," "open cluster," "full bloom") and subjected to three frost temperatures (-2.5, -5.0, -10.0 °C). The main advantage of this method, compared to other approaches, was that the exposition period and the time interval required to reach the target temperature were always constant (2 h). Furthermore, then, the twigs were placed in a climate chamber until full bloom, before the examination of the flowers and not further developed buds started. For the first two sampling stages (side green, green tip), the number of buds found in open cluster, "first white," and full bloom at the evaluation date decreased with the strength of the frost treatment. The flower organs showed different levels of cold hardiness and became more vulnerable in more advanced development stages. In this paper, we developed four empirical functions which allow calculating possible frost damages on sweet cherry buds or flowers at the investigated development stages. These equations can help farmers to estimate possible frost damages on cherry buds due to frost events. However, it is necessary to validate the critical temperatures obtained in laboratory with some field observations.

Spatiotemporal Variation of Frost within Growing Periods

“…Frost is among the agroclimate risks that are detrimental to crop and fruit production in most places of the mid and high latitudes [2,3]. Frost normally occurs when air temperature drops to or below 0 ∘ C resulting in ice formation on plant material and soil [4].…”

Spatial and temporal variability of the frost‐free season in Central Europe and its circulation background

“…Perennial crops such as fruit trees are very sensitive to fluctuating temperatures. Most damage at mid-latitudes occurs during the spring bloom season when below-freezing temperatures harm flower buds following the loss of cold hardiness (Rigby and Porporato, 2008;Kreyling et al, 2012;Winkler et al, 2013;Matzneller et al, 2016).…”

Occurrence and synoptic background of strong and very strong frost in spring and autumn in Central Europe

“…Dennis and Howell 1974;Proebsting and Mills 1978;Longstroth and Perry 1996;Miranda et al 2005;Chmielewski et al 2018). The occurrence of frost before the onset of blooming may cause damage to flower buds, but the damage is even larger in the blooming period, when frost may lead to complete loss of crop yield (Chmielewski et al 2004;Matzneller et al 2016). At mid-latitudes, most damage occurs during the spring bloom season, when below-freezing temperatures harm flower buds after the loss of cold hardiness; in a changing climate, this risk will remain, due to increasing variance of temperature (Rigby and Porporato 2008).…”