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

► Cluster drop between fruit set and maturity period in hazelnut was identified. ► There was significant effect on yield, % of good kernels and % of blank nuts. ► Cluster drop intensity had a significant effect on Mg and micronutrients content. ► Leaf N, Fe, Cu and B values were below optimum; P, K, Ca, Mg, Zn and Mn were above. ► This study gives valuable information when choosing hazelnut cultivars for planting.