Graft compatibility for new released Prunus rootstocks

Graft compatibility for new Prunus rootstocks recently introduced into the Spanish market or under selection in public and private programmes is assessed in nursery trials. Part of the evaluated material belongs to the Aula Dei Experimental Station (EEAD-CSIC) selection program in Zaragoza, Spain. Another group of rootstocks under test is from the private nursery Agromillora Iberia, S.L. Some of those rootstocks showed good adaptation to Mediterranean growing conditions and resistance to root-knot nematodes. As control, peach-almond (‘GF 677’), peach × P. davidiana (‘Cadaman’), other interspecific plum-based rootstocks (‘Damas GF 1869’, ‘Ishtara’) and different plum species (P. cerasifera: ‘Adara’; P. domestica: ‘Constantí 1’; P. insititia: ‘Adesoto’ and other ‘Pollizo de Murcia’ clones, ‘Saint Julien A’) are used. New evaluated rootstocks include: ‘Densipac R 20’ (P. besseyi × P. cerasifera), ‘Nanopac R 40’ (P. dulcis × P. persica), ‘Replantpac RR’ (P. dulcis × P. cerasifera), ‘AP 45’ [(P. besseyi × P. salicina) × P. armeniaca], ‘Aprimed AP 65’ [(P. armeniaca L. × P. cerasifera Ehrh) × P. pumila L. var. besseyi], and ‘LC 52’ (P. cerasifera × P. maackii), among others. To determine graft-compatibility, commercial cultivars of different Prunus species were budded on some of the evaluated rootstocks. They include: ‘Moniquí’ and ‘Portici’ (apricot); ‘Lauranne’, ‘Nonpareil’, ‘Penta’ and ‘Soleta’ (almond); ‘Angeleno’ and ‘Golden Japan’ (Japanese plum); ‘Big Top’ and ‘Sumergrand’ (nectarine) and ‘Aida’, ‘Carmen’, ‘Cordia’, ‘Ferrovia’, ‘Kovics’, ‘Krupnoplodnaja’, and ‘Sandor’ (cherries). Several degrees of graft incompatibility have been observed for the ‘translocated’ type of incompatibility. In general, peach-almond hybrids and slow-growing plums (P. domestica and P. insititia plums as ‘Adesoto’ and other ‘Pollizo de Murcia’ clones) were graft-compatible with peach, almond and Japanese plum tested cultivars. However, in the case of P. cerasifera, P. besseyi and interspecific hybrids with these species, performance differed substantially depending on the evaluated genotype.