Adopting vigorous olive cultivars to high density hedgerow cultivation by soil applications of uniconazol, a gibberellin synthesis inhibitor

Abstract

The high-density planting system recently adopted for olive, facilitates the use of efficient over-head mechanical harvesters. To accommodate the harvester only cultivars with restrained vegetative vigor can be used and managed to limit tree size while maintaining high productivity. Spray application of the 0.05% “Magic” (a commercial product containing 50 g L–1 uniconazol), or soil application of 2 and 4 g tree–1 “Magic”, were tested to control the canopy size of fruitful vigorous cultivars to suit the high density hedgerow system and over-head harvesting. Two year old plants were chosen for the initial application. Soil application of 2 g “Magic” (0.1 g tree–1 uniconazol) caused a satisfactory balanced growth inhibition of the vigorous cvs. Barnea, Leccino and Picholine to suit the high density hedgerow system. Thus, a significant increase of the choice of cultivars to be used for over-head harvesting could be significantly increased. The use of vigorous cultivars treated with uniconazol for over-head harvesting started in commercial plantations in 2006. In some cases an increase of the annual dosage was required with aging of the trees. This required increase of the annual soil application of uniconazol with aging of the trees needs further observations. An increase in fruit production due to the optimal uniconazol treatment was apparent, though results were rather erratic. Still, production in treated orchards was at least within the country’s average for each of the tested cultivars during the experimental years.