Ground cover management strategies in an Apulian oil-producing olive grove: Agronomic and ecological assessment proposals

Several studies have pointed out that ground flora in olive groves, such as in any orchard, should ideally combine adequate positive effects on the agro-environment with only marginal negative competitive effects on the olive plants. This paper reports the results of an experiment carried out in an irrigated olive orchard (cv. Leccino), located in the area of Savelletri, Puglia (southern Italy), regarding the effects of ground flora as a consequence of different management techniques. An aggregate index is proposed, able to provide a comprehensive evaluation of flora from both an ecological and agronomic point of view. Four different weed control strategies were compared: A) seeding, every other year, of a cover crop (Vicia sativa L.) chopped in springtime; B) weed control using a mixture of a systemic herbicide and a residual herbicide; C) weed control using a systemic herbicide only; D) chopping. The results revealed that the different management practices largely influenced the ground cover values in each study year, but not the yield. Ground cover features, assessed both from an agronomic and ecological point of view varied in particular, as was well reflected by the applied index, which proved to easily and effectively describe the flora features in different plots.