Reperimento e valutazione bio-agronomica del germoplasma corilicolo etneo

Hazelnut [Corylus avellana (L.)] is cultivated on Mount Etna between 500 and 1200 meters above sea level in uneven soils and slopes and it has a high landscape value. Production costs are particularly high and growers frequently reduce cultural practices so that the yield is often compromised. However, in rational orchards, higher yields may be achieved using appropriate cultural practices. A territorial recognition of hazelnut cultivation in Mount Etna area, as reported in a previous work (Nicolosi et al., 2007), has been useful to identify locally diffused accessions selected by the growers; some of these appear to be really interesting and should be preserved from genetic loss. The aim of this research was to analyze some aspects related to cultural practices adopted in the Etna area and, particularly, to verify the effect of foliar fertilization on yield parameters. The analyses were carried out from 2005 to 2007 in a 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. We applied a 8.5% organic nitrogen fertilizer and an NPK fertilizer (20:20:20) plus chelated micro-elements at a concentration of 3%. Two different trials, with ten plants each, were set up. Trial A: plants were treated twice, in late May after fruit set 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 a significantly higher kernel weight and nut size as compared to the control plants; there were also significant differences in the percentage of blanks. The foliar fertilization practices can be conveniently combined with pest control treatments so that it has little effect on production costs.