Fruit set, yield and carpological characteristics of five almond cultivars (Prunus dulcis (Mill.) D.A. Webb) as affected by different soil management in Southern Italy

Almond cultivation is of considerable importance among fruit crops of the warm-temperate climate and has been growing steadily worldwide since the early 1990s, reaching about 1.87 million cultivated hectares in 2016. In the Mediterranean Region, where the main parts of almond orchard are located, high erosion rates have been observed in many tree crops, including almond. Tillage is the traditional and prevailing soil management technique in the Mediterranean Basin despite many studies reported negative effects on soil quality highlighting the significant increase of soil erosion determined by this technique. But very few data are available in the literature, especially for almond, about the effects on vegetative and reproductive activities, yields and fruit quality of tree crops. The trial aimed to evaluate the effect of three different soil management techniques (‘conventional tillage’, ‘no-till without cover crop’, ‘frequently mown cover crop’) on five almond cultivars (‘Ferragnés’, ‘Filippo Ceo’, ‘Genco’, ‘Supernova’, ‘Tuono’), grown in a commercial almond orchard located in Southern Italy. Average fruit set, yield tree-1 and dimensional parameters of fruits and kernel were determined. The tested cultivar showed difference in their fruiting behaviour regarding the distribution of both floral buds and fruits on different types of bearing shoots. This suggested, with the aim to increase productivity, that during pruning it is necessary to mainly preserve a different type of shoots in each one of these cultivars. For all the cultivars evaluated, quite negative effects resulted in terms of both yield and carpological parameters for the ‘no tillage’ treatment, while the best performances were observed for the ‘conventional tillage’ treatment.