The effect of planting distances and tree shape on yield and harvest efficiency of cv. Manzanillo table olives

The effect of different tree shapes and spacing on the yield, fruit characteristics, fruiting alternance and harvest efficiency of cv. Manzanillo table olives was studied under two different climatic environments. Four tree shapes were developed, ‘High trunk’, ‘Low trunk’, ‘Multi trunk’ and ‘High hedge’. Spacing was kept uniform either within the rows (5 m) in the coastal plain plot at Bet-Dagan and between the rows (7 m) in the hot continental Bet-Shean valley. The varying distances ranged in both regions according to the potential tree size between 5 and 8 m. Three ‘on’/’off” cycles between age 7 and 12 were chosen for the major comparisons between the tree forms and accompanying spacing. The cumulating yield during the first 13 years per hectare was the highest on the ‘Multi trunk’ trees in both growing regions followed by the ‘High hedge’ system in the coastal plain and the ‘Low trunk’ in the continental valley. In both regions the high trunk system developed the lowest fruit yield per hectare, though in Bet-Dagan per tree the cumulative yield was the highest. This was in part due to the plant spacing affecting canopy size of the trees in each training system. Fruit size was rather similar in all four training systems but larger in the coastal plain with the generally lower yield and particularly in both regions during the ‘off’ years. The oil content in the fruits of the ‘High trunk’ trees was somewhat lower than the oil in fruit of the other tree shapes. The mean oil content of all treatments was annually in the hot continental region significantly lower than in the coastal plain. The level of alternate bearing varied considerable between the training systems, the regions and the years but was high and inconsistent in all three ‘on/off’ year cycles. Manual harvest efficiency was significantly increased by reducing the tree size and thus increasing the crop value. Harvest efficiency of the ‘High hedge’ system could be improved by using a moving platform along the hedge for the upper fruit collection. Still, for manual harvesting the highest crop values as well as simple tree training and earliest bearing were achieved in the ‘Multi trunk’ system in both regions.

► The study compared four training systems of ‘Manzanillo’ in two climatic regions.
► High hedgerow training was production and harvest efficient in the coastal plain.
► A multi trunk training system produced in two climatic regions the highest crop value.
► The tree shape–spacing systems had no significant effect on alternate bearing.