Observations on the frost resistance of the fernor walnut variety during the rest period (january-april), under the pedoclimatic conditions in Sălcioara area, Dâmboviţa county

Abstract

t is well known that walnut varieties with lateral fructification have a lower resistance to temperature variations during relative rest and on the entering vegetation.In the first decade of January 2017, in Salcioaravillage, Dambovitacounty there was recorded extremely high variations in the negative temperatures, which could affect the viability of the male florids (men) and the small unisexed female buds.At the end of April (26-28 April) there were late spring frosts that caused massive tissue necrosis of young tissues in native walnut trees and partial frosts of male ‘Fernor’sprouts found in the phenophase of swelling of the buds.If the autochthonous genotypes produced 80% of the production of walnuts in the year 2017, these late frosts did not affect the subsequent developmentof fruit buds in the ‘Fernor’variety. Approximately 10% of male florid shoots (avenues) showed partial frostbite without having their total pollen emission capacity and 3% of small buds unisexed females were affected by frost.