Prunus Rootstock Evaluation to Root-knot and Lesion Nematodes in Spain.

Two screening and one resistance verification trial involving 20 Prunus rootstocks were conducted under greenhouse conditions against Meloidogyne spp. and Pratylenchus vulnus. Most of the rootstocks were experimental genotypes or new commercial peach and plums of Spanish and French origin. Nearly all are interspecific hybrid rootstocks. In the first trial, the rootstocks Bruce, Cadaman, Mirac, G x N No. 15, Cachirulo x (G x N No. 9), and P. myra x peach were immune or resistant to a mixture of seven isolates of M. incognita. In the second screening trial, the hybrid plum P 2588 was a poor host to a mixture of four isolates of P. vulnus. The remaining seven rootstocks were good hosts to the root-lesion nematode. In the resistance verification trial GF-31, G x N No. 15, Torinel, AD- l 01, Monpol, Nemaguard, and Cadaman maintained a high level of resistance when tested against a mixture of 17 isolates comprising M. incognita, M. javanica, M. arenaria, M. hapla, and M. hispanica. Barrier peach suffered a partial loss of resistance not detected in previous tests.