Indagine sulla coltivazione del noce da legno in Campania

Abstract

Abstract: A total of 13 timber walnut (Juglans regia L.) plantations located in the Campania region (Southern Italy) and ranging from 7 to 27 yrs in age were surveyed. The main site (elevation, soil texture, summer precipitations) and growth (stem diameter at 1.30 m and stem height, wood yield) characteristics were evaluated. Furthermore, stem form and quality (presence of knots and mechanical damages), as well as the stem radial increment for a two-years period (1999-2000) were assessed. For the plantations with age from 7 to 15 yrs., the average stem radial increment (obtained dividing stem diameter by plantation age) was negatively correlated with soil clay content while the radial increment for the two-year period 1999-2000 was positively correlated with summer (June, July and August) precipitations. The highest growth rates were found in sites at elevation less then 600 m a.s.l., with a clay content less than 25-30% and summer precipitation above 140-150 mm. Overall, the productivity of the walnut plantations in Campania region was comparable to that observed in other regions in Central-Italy (Bordin et al. 1995). In favourable site conditions, a minimum rotation age of about 30-35 yrs may be expected. In some plantations stems were frequently affected by knots and/or mechanical damages; therefore, the improvement of pruning and other growing techniques is needed in order to preserve wood quality.