PHENOLOGICAL DEVELOPMENT AND GROWING DEGREE DAYS IN GEVUINA AVELLANA MOL.

Gevuina avellana Mol. is a temperate tree which produces nuts with interesting nutritional and pharmacological properties. Despite this, there is a lack of information about the effect of temperature on its phenological development, specially on nut growth. In Valdivia, Chile, a selection of trees was evaluated during several years to describe the new shoot, leaves, leaflets, anthesis and nut development. Phenological development data was plotted against the sum of growing degree days. ANOVAs tests and correlation analysis were conducted to assess changes in nut traits in regard to sum of growing degree days (>10°C). Phenological development was well related to the sum of growing degree days, and three main stages were observed: nut and shoot growth period, full flowering period, and nut drop period. Variations in diameter, dry weight, and moisture content for nut-in-shell, shell and kernel, were significantly (P<0.05) and highly correlated with the sum of growing degree days (r≥0.779 and ≤-0.969). Kernel diameter and dry weight significantly increased (P<0.05) until the sum of 500 to 600 and 800 to 900 growing degree days, respectively. Results are useful in plant breeding, environment selection for orchards establishment and for their cultural management.