Profitability of Artificial Pollination in ‘Manzanillo’ Olive Orchards

The fruit set in monovarietal ‘Manzanillo’ olive orchards is significantly increased under cross-pollination. This response lead to pollination designs including pollinizer selection, the number of pollinizer trees per hectare and their distribution in the orchard. However, the assignment of a substantial area to pollinizers of lesser commercial value might decrease profits. The strong influence of variable climates on the overlap of the blooming phenology of ‘Manzanillo’ and its pollinizer, and on pollen production and dispersal, are also notable risks. Artificial pollination is a feasible alternative to pollination designs, especially for wind-pollination crops such as olives. Here, we present the effects of treatments with different number (zero, one, two or four) of mechanical applications of ‘Barouni’ pollen on fruit set, size, yield, and cost–benefit ratios in heavy- and light-flowering trees of ‘Manzanillo’ trees situated in monovarietal orchards in Sonora, Mexico. Our results showed that, in “on” years (seasons where most trees display abundant flowering), a larger number of cross-pollen artificial applications increased more the final fruit set, yield and, hence, the profits. Fruit size was scarcely affected by the number of applications, although treatments with lower fruit sets had a higher proportion of large-sized fruit and less fruit of petite size. Despite its higher costs, the higher increase in yield made it more profitable to apply cross-pollination four times throughout the blooming period. On the other hand, no significant differences were observed among treatments, regardless of the number of pollinations, in the “off” season (the season in which most trees had a light flowering level).