TEN YEARS OF RESEARCH ON PEACH AND NECTARINE IN A HIGH DENSITY SYSTEM IN THE VERONA AREA.

This paper reports the results of studies conducted since 1974 in the Verona area on peach (cvs. 'Springcrest', 'Redhaven') and nectarine (cvs. 'Early Sungrand', 'Flavor top', 'Stark Redgold'), budded on 'GF 655-2', trained to a free spindle and spaced at 4 x 2 m (1 250 trees/ha).

A second trial was begun in 1976 on trees of 'Suncrest' and 'Stark Redgold' planted at densities of 1 250, 1 655 and 2 500 trees/ha (4m x 10, 1.5 and 2.0m respectively) and trained to free spindle.

Trees began cropping during the second growing season, giving varying yields according to the different cultivars and densities.

The cumulative yields reached by the eighth growing season (1983) were very satisfactory, ranging from 156.5 to 274.6 tons/ha with 'Springcrest' and 'Stark Redgold' respectively. Such yields are remarkably higher than those commonly obtained with the traditional planting systems in the Verona area.

Concerning the different densities, the highest cumulative yield by the sixth season of growth was reached with trees spaced at 4.0 x 1.0 m (2 500 trees/ha). However, the difference between the distances 4.0 x 1.0 m (2 500 trees/ha) and 4.0 x 1.50 m (1 665 trees/ha) was quite small, especially for 'Stark Redgold'. Therefore, considering the higher cost of establishment, the higher input of labour for pruning and the difficulties in maintaining the canopy in a balanced growth pattern in trees planted at the highest density, distances of less than 1.5 m along the row do not appear suitable. A greater distance between the rows (4.5 m) seems advisable, in order to facilitate cultural operations.