EXTINCTION TRAINING OF SWEET CHERRIES IN FRANCE - APPRAISAL AFTER SIX YEARS
For a number of years in France, the Solaxe training system has been proposed for sweet cherries as a way of increasing tree density/ha and reducing time before the first commercial crop. Planting distances usually are 4.5 to 5 m between the rows and 1.5 to 2 m within each row, giving tree densities ranging from 1000 to 1500 trees/ha. Bending, rather than heading cuts, is used to control the vegetative growth of the trunk (at a height of 2.5 to 3.5 m) and side branches. For certain cultivars, bending also is used to increase fruiting. More recently, the removal of fruiting spurs from side branches has been suggested as a training tool for improving the balance between vegetative growth and fruit load. This method, known as extinction, has now been integrated in training programs in several commercial orchards with the collaboration of the applied research network Mafcot (Maîtrise de la Fructification - Concepts et Techniques; Fruiting Control - Concepts and Applications). This paper presents two experiments carried out (i) on 10- and 6-year-old trees to compare standard winter heading cuts and extinction, and (ii) on 6-year-old trees to evaluate how cultivar ('Burlat', 'Duroni 3', 'Sumele', 'Summit') affects sweet cherry growth and fruiting responses to various heading cuts and extinction treatments, all involving the removal of ~30% of the fruiting spurs. Synthesis of these experiments confirms the benefits of the extinction method, as compared to standard heading cuts, for improving fruit size while maintaining a good balance between vegetative growth and fruiting. Although not quantified in this study, these extinction experiments resulted in two unexpected side effects that are now being studied carefully: enhanced fruit maturity (by 2 to 4 days) in the early-ripening 'Burlat' and reduced sensitivity to European brown rot. The better light and air penetration within the canopy brought about by extinction training may explain these observations.
Claverie, J. and Lauri, P.E. (2005). EXTINCTION TRAINING OF SWEET CHERRIES IN FRANCE - APPRAISAL AFTER SIX YEARS. Acta Hortic. 667, 367-372
Prunus avium, Tabel® Edabriz, Burlat, Duroni 3, Sumele, Summit, Solaxe, fruit size, fruit load