Bioagronomic evaluation of peach rootstocks by the italian MiPAF targeted project

Evaluation of nine peach rootstocks (the peach seedlings ‘Rubira’, ‘P.S. A5’, ‘P.S. A6’ and the hybrid clones ‘Ishtara-Ferciana’, ‘Julior-Ferdor’, ‘Jaspi-Fereley’, ‘Citation-Zaipime’, ‘Barrier 1’ and ‘GF 677’), grafted with cultivar ‘Suncrest’, has been carried out in eight different locations in Italy, inside the MiPAF (the Italian Ministry of Agriculture) Project “Rootstocks evaluation”, in order to assess the bioagronomic characteristics of the rootstocks recently introduced on the Italian nursery market. Orchards were distributed throughout Italy: two in the north (Cuneo and Forlì), two in the center (Pisa and Ancona) and four in the south and on Sardinia Island (Caserta, Metaponto, Catanzaro and Cagliari). Each of the eight orchards was planted in 1995, with 15 trees per rootstock, at the distance of 5 x 5 m on different soil conditions and trained to free open vase. This report highlights the main results obtained after 8 years of growth (4 years of production). Data on vegetative and productive activity and on fruit quality are reported and summarized either per rootstock or per location. Independently of the location considered, ‘GF 677’ and ‘Barrier 1’ rootstocks appeared to be very vigorous and productive, with positive effect on mean fruit weight. The last clone constantly delays (5-7 days) bud burst, blooming time, fruit harvest and leaf fall time. Peach seedling rootstocks ‘Rubira’, ‘P.S. A5’ and ‘P.S. A6’ performed well in good soil conditions, where productivity and vigor were respectively only slightly lower or at least 20% less than ‘GF 677’. On the contrary, in low fertile soils they showed vigor, yield and fruit quality lower than trees grafted on the peach x almond hybrid. Diffuse symptoms of graft incompatibility have been observed on the two plum hybrid rootstocks ‘Citation’ and ‘Jaspi’, while the other two, ‘Julior’ and ‘Ishtara’, performed quite well as regard yield per tree and fruit size. ‘Julior’ and ‘Jaspi’ showed important sucker ability on almost 50% of trees. Peach seedlings ‘P.S. A5’ and ‘Ishtara’ appeared to be very interesting for high density plantings in very fertile soils because their vigor allows to increase up to 30% the planting density established in the trial orchards