Agronomic behaviour of 35 blueberry cultivars in central Italy

Rising demand for blueberries for fresh consumption and the need to reduce transportation costs of the product have triggered the extension of sustainable and cost-efficient production systems in Italy. This study analyzed the adaptability of old and new cultivars to new cultivation areas in central Italy. The evaluation of 35 blueberry cultivars (northern highbush, southern highbush, rabbiteye) was carried out at the experimental fields of the CREA-Fruit Tree Research Center (CREA-FRU) in Rome, central Italy, under Mediterranean climatic conditions. Two different cultivation systems were compared: 1) traditionally in the field (TF) with acid peat and a specific fertigation programme, and 2) cultivation in plastic containers (CS) with a specific acid substrate. In both systems, drip irrigation was applied. In TF, after an initially good growth during the first year, plants had reduced vegetative and productive activity in the following two years, probably due to unfavourable pH of the soil, despite a constant acidification of the irrigation water. Yields differed widely among cultivars within all observed species, with a minimum of slightly more than 110 g and a maximum of 2.460 g plant^-1. Average fruit weight was also variable, with a minimum and a maximum of 0,86 and 2,27 g, respectively. In the CS system, the plants resulted more vigorous, with a very intense vegetative renewal, which lead to an increased unitary yield of up to a maximum of 8.900 g plant^-1, but slightly reduced the average fruit weight. Overall observations suggest that CS cultivation can be considered a good solution for new areas where the chemical soil proprieties do not match the requirements of blueberry plants. Compared to traditional cultivation, the CS method significantly increased the yield per plant and was advantageous from an economical point of view. In spite of the initial cost of containers, production costs were significantly lower due to easy management of irrigation and fertilization, and higher efficiency of manpower.