Evaluation of Pecan [Carya illinoinensis (Wangenh.) K. Koch] Cultivars for Possible Cultivation for Both Fruit and Truffle Production in the Puglia Region, Southeastern Italy

Yield and different nut parameters were measured for two growing seasons on mature (28-29 years) trees of 11 pecan cultivars grown in an experimental orchard located in the Puglia Region, Southeastern Italy. 'Shoshoni' and 'Shawnee' pecan seedlings were inoculated with three truffle species (Tuber borchii-known as the 'whitish truffle', T. aestivum-called the 'summer truffle', and T. melanosporum-the common 'Black truffle') and investigated for six months. The level of ectomycorrhizal colonization was assessed 6 and 12 months after inoculation. Results indicated that 'Wichita', 'Shoshoni', and 'Pawnee' performed well in the pedoclimatic conditions of the area with a yield higher than 20 kg/tree and a kernel dry weight of approximately equal to 3 g. These preliminary yield results suggested that some pecan cultivars could deserve consideration for cultivation in the Puglia Region, whereas others with low yield and a stronger alternate bearing should not be considered. Plant height, number of leaves, chlorophyll content (expressed as a SPAD unit) and stem diameter partially indicated the increase in ecological fitness in truffles-inoculated plants. Successful mycorrhization indicated 'Shoshoni' and 'Shawnee' as suitable to establish ectomycorrhizal symbiosis with T. aestivum, T. borchii, and T. melanosporum cultivation under Puglia climatic conditions. The results also showed that the applied protocol was adequate to obtain healthy mycorrhized seedlings appropriate for commercialization and plantation for truffles production on pecan in the future.