Cluster drop phenomenon in hazelnut (Corylus avellana L.). Impact on productivity, nut traits and leaf nutrients content

Abstract

Nut yield per bush, nut and kernel traits and nutritional status of leaves of three hazelnut cultivars ('Tonda Gentile Romana', 'Nocchione' and 'Istarski Duguljasti') were examined under different intensity of cluster drop during 2005-2007 in Western Serbia. Cluster drop between fruit set and maturity period was identified and significantly influenced nut yield, % of good kernels and % of blank nuts, while did not affect the caliber, nut and kernel weight, percent kernel and shell thickness. With exception of leaf Mg, the content of macronutrients was not significantly influenced by different intensities of cluster drop, whereas content of micronutrients was significantly affected by cluster drop intensity within each cultivar. Deviation from optimum percentage (DOP index) indicated that leaf N contents were lower than optimum, whereas a high excessive leaf P, K, Ca and Mg contents were found in all cluster drop intensity. Leaf Fe, Cu and B contents were lower than normal, whereas an excessive Zn, especially Mn contents were found in all cluster drop intensity. The ΣDOP values indicated that intensity of imbalances were higher among micronutrients than macronutrients content. Significant correlation was observed between nut yield and nut weight, good kernels and blank nuts, leaf P and Ca or Zn, and Ca and Zn. Generally, the results from this study could be a useful tool for hazelnut cultivars choosing for growing in similar pedo-climatic conditions. © 2012 Elsevier B.V.