Nut and kernel growth and shell hardening in eighteen hazelnut cultivars (Corylus avellana L.)

Abstract

Valentini N., Moraglio S.T., Rolle L., Tavella L., Botta R. (2015): Nut and kernel growth and shell hardening in eighteen hazelnut cultivars (Corylus avellana L.). Hort. Sci. (Prague), 42: 149-158.Growth and development of nuts and kernels were measured in 18 hazelnut (Corylus avellana L.) cultivars from cluster appearance until nut maturity and drop. At harvest, shell thickness and force to penetrate the shell were determined and related to the incidence of nut weevil damage. The force to penetrate the shells started to increase when nuts reached 80-90% of their final size, and continued until kernel full size. During nut growth, shell hardness and kernel size were highly correlated (R 2 = 0.921). At maturity, values of force ranged from 46.7 to 185.7 N. Values of nut weevil damage ranged from 0.6 to 24.4%. At harvest, the force to penetrate the shells was highly correlated with the shell thickness (r = 0.945) and negatively correlated with the nut weevil damage (r = -0.564). Late onset of nut development was associated with a high percentage of nut weevil damage (R = 0.638). These information can be used to model nut development and provide important tools for planning orchard management activities.

Hazelnut and Walnut Nutshell Features as Emerging Added-Value Byproducts of the Nut Industry: A Review

“…Structurally, nutshells (rich in lignocellulosic compounds) are characterized by exhibiting high hardness and firmness [5,6,44]. Valentini et al [45] studied such properties, reporting values of force required for penetration of shells (from 18 hazelnut cultivars from different countries in Europe: Germany, France, Italy, Spain and England).…”

Trend Analysis of Different Climate Parameters and Watering Requirements for Hazelnut in Central Italy Related to Climate Change

“…Ripening occurs in August/September, according to the cultivar. A lack of water during nut growth (from June to July) results in reduced nut size, while during kernel growth (July and August) it leads to poorly filled nuts [38]. The seasonal cycle of hazelnuts shows the overlapping of different vegetative and reproductive processes (shoot growth, fruit set, shell expansion, kernel filling, flower bud initiation, and differentiation) from the beginning of June to the end of August, depending on the cultivars and growing environments, and this makes the availability of water a priority to overcome the physiological competition between different organs [13].…”

Hazelnut and Walnut Nutshell Features, as Emerging Added Value by-Products of the Nut Industry: A Review

“…[5,6,44]. Valentini et al (2015) [45] studied such properties, reporting values of force required for penetration of shells (from 18 hazelnut cultivars from different countries in Europe: Germany, France, Italy, Spain and England). These values ranged from 48.0 ± 3.8 to 185.7 ± 4.0 Newton (N) (an average of 87.89 ± 4.0).…”