Università degli studi di Sassari, Dipartimento di Economia e sistemi arborei
Abstract
An open field research and a pot-grown plant trial have been planned in order to evaluate the
influence of mineral nutrition, i.e. nitrogen fertilization, on the agronomic and qualitative response of
myrtle variety selections. In a randomized field located in the DESA experimental station in Oristano,
Sardinia (Italy) during February 2004 three different levels (0g, 50g and 100g) of NH4NO3 at 26%
were applied on 15 plants of three myrtle cultivars named BOS1, BOS 2 and CPT 5.
At harvest time plant size (height and diameter) and yield were recorded and on 100 leaves the
macro and micro elements (N, P, K, Na, Ca, Mg, Cu, Zn, Fe e Mn) content was measured. On 100 ripe
fruits, berry and seed weights were determined and the amount of SST, total acids, pH, polyphenols
and anthocyans were also recorded. Nitrogen fertilization induced increase in fruit number and yield
and reduced fruit size in different extent among the selections. On fruit quality (total acids, SST) the
influence of the genetic factor was higher than fertilization.
In the pot-grown plant trial the response of three-year old self rooted myrtle plants of the CPT 5
variety selection to an eight nitrogen fertilization levels applications (0g, 4g, 8g, 12g, 16g, 20g, 24g,
28g,) was evaluate measuring the percentage of plant survival, the leaf number and the macro and
microelements content. The nitrogen fertilization (until 12g) positively influenced plant growth while
higher levels of nitrogen caused toxic effect
