Growth dynamics and reproductive activity of annual shoots in the walnut cultivar 'Elit'

Abstract

An architectural analysis of a fruiting branch in the Slovenian variety 'Elit' was conducted during three successive years. The fruit bearing branch was constructed of a three-year-old parent shoot plus all corresponding two-year-old shoots and annual shoots (1Y). The construction of the bearing branch during the time caused a statistically significant increase in the number of annual shoots. The basal diameter and the length of 1Y significantly depended on a year whereas their angles did not. In spite of decreasing length of 1Y, the number of vegetative buds per shoot increased from the first to the third year of observations. The number of nodes was closely correlated with the length of the shoots. Activity points on the 1Y were most often on the apical two or three nodes, what was expressed by a marked acrotony. The number of active points varied as the tree matured. The ratio fruit bearing 1Y / total 1Y was 0.47 in year 1; 0.18 in year 2; 0.74 in year 3. It points to the slightly alternance. As the tree grew the number of flowering buds per 1Y as well as the number of female flowers per 1Y increased. The results of the three-year-long research show some growth and development rules in the walnut cultivar ‘Elit’, however, they do not allow a reliable prediction of the following activities. We assume that this will be possible after another three-year-long analysis, with the help of the Hidden Mark Model.