Almond fruit tolerance to frost temperatures in new Spanish cultivars

D. Masip, L. Torguet, I. Batlle, S. Alegre, X. Miarnau
Late blooming is a desired character in new almond cultivars to prevent spring frost damages at flowering time. Thus, it is one of the main aims in the Spanish almond breeding programs. However, to delay spring frost problems, it is also important that the genetic cultivar is tolerant to frost damage, during blooming, fruit set and early growth. Therefore, it is important to assess the cultivar tolerance level to low temperatures in the most sensitive phenological stages. In earlier works, we evaluated the flower tolerance to low temperatures, finding some differences between genotypes. During one year, different frost periods were simulated in a climatic chamber set with a temperature and humidity program, to assess frost damage at ‘H’ stage (fruit set) using 20 cultivars. Three replications of five samples of one-year-old shoots, carrying 10-15 fruits, were tested setting 5-6 temperatures (average of 750 fruits cultivar-1 in total). The lethal temperatures to produce damage in a population percentage (LT10, LT50 and LT90) were calculated for each cultivar at ‘H’ stage. The results obtained showed differences in susceptibility to low temperatures between the 20 cultivars evaluated; however, these differences were always lower than 2°C.
Masip, D., Torguet, L., Batlle, I., Alegre, S. and Miarnau, X. (2018). Almond fruit tolerance to frost temperatures in new Spanish cultivars. Acta Hortic. 1219, 67-72
DOI: 10.17660/ActaHortic.2018.1219.12
Prunus dulcis, cultivar, tolerance, lethal temperature, damage

Acta Horticulturae