Pollination designs in ʻManzanilloʼ olive orchards

Abstract

ʻManzanilloʼ groves in non-traditional olive producing countries often suffer pollination deficits that reduce fruit set, fruit size and yield. Growers then should design orchards with a minimum number of compatible pollinizers to enhance ʻManzanilloʼ productivity. In order to select plantation designs considering the most effective distance between pollen donors and main variety but without sacrificing too much area for less valuable but largely required pollinizers, we compared three plantations with ‘Barouni’ trees acting as pollinizers at increasing distances (8, 32 and 80 m). In these three orchards, we analyzed pollen-pistil interaction and measured fruit set and size and estimated ‘Manzanillo’ yield and economic returns. The results showed that close proximity (8 m) between the main variety and pollinizers is beneficial in terms of flower fertilization levels and fruit set. However, the reduced fruit set in pollination designs with more distant rows between main variety and pollinizer was partially compensated by an increase in fruit weight and better fruit size distribution (leading to higher price per unit). This trend occurred in “on” as well as in “off” flowering seasons. Considering the incomes obtained we recommend for our experimental conditions, a close distance between the main variety and pollinizers increasing the proportion of the latter.