Frost Resistance in Seven Commercial Walnut Cultivars
Walnut orchards currently extend worldwide and are even found in areas less climatically suitable to obtaining large crops.When choosing cultivars, it is essential for bursting to take place outside the winter frost period, but the potential danger of early frost in autumn is often disregarded.Early frost events could be more damaging as the species are enlarging their vegetative cycles as the result of climatic change.Although walnut trees can thrive in continental climates and can withstand temperatures of as low as-30℃ during dormancy, the response of the main walnut cultivars to frost damage has hardly been studied.In this work, we assessed the response of the main commercial cultivars planted in many new orchards throughout the world, such as: Chandler, Fernette, Fernor, Franquette, Howard, Serr and Tulare to sub-zero temperatures.Budsticks of these cultivars were submitted to sub-zero temperatures:-8,-12,-16 and-20℃, in a controlled climatic chamber.Frost damage was evaluated by the loss of electrolytes from basal slices of budstick in a water solution.Based on the damage observed at each of the temperatures studied, the value of LT50 (℃) was calculated for each cultivar following adjustment to a non-linear model (logistic 4p) proposed for walnut trees.There were differences on winter frost resistance among cultivars, Chandler was the most resistant and differed from Tulare, Serr, Howard, Franquette or even Fernor.Damage by frost autumn simulation resulted in a different cultivar ranking of susceptibility being Serr and Fernette significantly less damaged by sudden autumn frost than Chandler, Franquette or Tulare.
Juglans regia Persian walnut supercooling adaptive traits winter frost autumn frost
N.Aletà A.Vilanova E.Tomàs M.Guàrdia
Institut de Recerca i Tecnologia Agroalimentàries (IRTA) Torre Marimon,08140,Caldes de Montbui Spain
国际会议
The 7th International Walnut Symposium(第七届世界核桃大会)
山西汾阳
英文
389-393
2013-07-20（万方平台首次上网日期，不代表论文的发表时间）