Effect of foliar fertilization on hazelnuts growing in Mount Etna area

Hazelnut [Corylus avellana (L.)] is cultivated on Mount Etna between 500 and1200 meters above sea level in uneven soils and slopes and it has a high landscapevalue. Production costs are particularly high and growers frequently reduce culturalpractices so that the yield is often compromised. However, in rational orchards,higher yields may be achieved using appropriate cultural practices. A territorialrecognition of hazelnut cultivation in Mount Etna area, as reported in a previouswork (Nicolosi et al., 2007), has been useful to identify locally diffused accessionsselected by the growers; some of these appear to be really interesting and should bepreserved from genetic loss.The aim of this research was to analyze some aspects related to culturalpractices adopted in the Etna area and, particularly, to verify the effect of foliarfertilization on yield parameters. The analyses were carried out from 2005 to 2007 ina flat field placed in the north-east of Mount Etna, in Castiglione di Sicilia district.The treatments consisted of foliar fertilization applied in different periods. Weapplied a 8.5% organic nitrogen fertilizer and an NPK fertilizer (20:20:20) pluschelated micro-elements at a concentration of 3%. Two different trials, with tenplants each, were set up. Trial A: plants were treated twice, in late May after fruitset and in late June during nut increment. Trial B: plants were treated as for trial A,but a third treatment was applied in mid-July during shell hardening. In September,100 nuts per tree were used to calculate nut and kernel weight, nut and kernel size,kernel percentage and frequency of blanks. The treated plants showed asignificantly higher kernel weight and nut size as compared to the control plants;there were also significant differences in the percentage of blanks. The foliarfertilization practices can be conveniently combined with pest control treatments sothat it has little effect on production costs.