EVOLUTION OF PLANTING AND TRAINING SYSTEMS IN APPLE AND PEACH ORCHARDS OVER 25 YEARS OF INTENSIVE FRUIT INDUSTRY DEVELOPMENT IN CHILE

The fruit industry in Chile has changed significantly in the past 25 years. In the late seventies, apple and peach orchards were characterized by standard cultivars, low density (8×8 m for apples and 5×5 m for peaches) and open vase trained trees grown on seedling rootstocks. Even when dwarf apple rootstocks were introduced in early seventies planting densities remained low. Since then the fruit industry has been highly innovative and advances have been made through trial and error. Peach orchards have been steadily intensified, predominantly using denser orchards with refined forms of the open vase system, with the perpendicular Vee (1,000 trees/ha), or three arm trees (700 trees/ha) currently being the most common systems. The most common rootstock for peach has been Nemaguard. With apples, as spur ‘Delicious’ type cultivars were introduced in late seventies (grafted on seedling), higher planting densities were used (400-700 trees/ha, pollenized with ‘Granny Smith’ on MM.106 or M.7 rootstocks). The trees were trained to the central leader training system but in many cases, those orchards failed to be highly productive because high precocity resulted in leader stunting and lower than optimum planting density. With the introduction of bicolored cultivars in the early nineties (mainly ‘Gala’ and ‘Fuji’ strains), MM.106 became the standard rootstock with densities from 700 to 1000 trees/ha and vertical axe tree training. Many of these orchards had excessive vigor with permanent tier branches that were too strong resulting in shading of the lower and inner tree canopy. In the recent past, many of these orchards have been turned into solaxe, resulting in a calmer tree. Currently there is a strong trend toward denser orchards (2,000 or more trees/ha) using M.9 rootstock, and adopting tree forms as tall spindle, vertical axe or solaxe. As the industry moves forward with replanting to higher density orchards, the primary challenges are replant disease and high density orchard design and management.