Land use at landscape and field scales can increase the diversity and abundance of natural enemies for pest control. In this study, we investigated interactions between landscape elements (semi-natural vegetation, olive orchards, vineyards, other agricultural areas) and inter-row management (vegetation cover vs. bare soil) in relation to arthropod populations in Andalusian vineyards. Arthropods were collected from grapevine foliage in 15 vineyards using suction sampling. Landscape structure was analyzed within a 750 m radius surrounding the studied vineyards. Arthropods were categorized into functional groups (predators, parasitoids, herbivores), and their responses to the most influencing factors were analyzed by likelihood methods and model selection. Of the total of 650 arthropods collected, 48% were predators, 33% herbivores and 19% parasitoids. Numbers of predatory aeolothrips, parasitoids and herbivorous cicadas in the study vineyards decreased with an increased proportion of vineyards in the surroundings. Spider populations in vineyards increased with increasing proportions of other agricultural fields (non-flowering crops) in the surroundings. Semi-natural elements and olive orchards had no influence on the abundance of collected arthropods. We observed synergistic effects between landscape elements and inter-row management. The total numbers of arthropods, herbivores and parasitoids in vineyards benefitted from inter-row vegetation, while spiders benefitted from bare soil. Our findings underline the importance of both surrounding landscape elements and vineyard ground cover management to promote beneficial arthropods for potential natural pest control.
The large amount of olive cultivars conserved in germplasm banks can be used to overcome some of the challenges faced by the olive growing industry, including climate warming. One effect of climate warming in olive is the difficulty to fulfill the chilling requirements for flowering due to mild winter temperatures. In the present work, we evaluate seven olive cultivars for their adaptation to high winter temperatures by comparing their flowering phenology in the standard Mediterranean climate of Cordoba, Southern Iberian Peninsula, with the subtropical climate of Tenerife, Canary Islands. Flowering phenology in Tenerife was significantly earlier and longer than in Cordoba. However, genotype seems to have little influence on the effects of the lack of winter chilling temperatures, as in Tenerife. This was found even though the cultivars studied had a high genetic distance between them. In fact, all the cultivars tested in Tenerife flowered during the three-year study but showed asynchronous flowering bud burst. ‘Arbequina’ showed an earlier day of full flowering compared with the rest of the cultivars. The results observed here could be of interest to refine the phenological simulation models, including the length of the flowering period. More genetic variability should be evaluated in warm winter conditions to look for adaptation to climate warming.