Damage by a Lesion Nematode, Pratylenchus vulnus, to Prunus Rootstocks. J. Pinochet, Departamento de Patologia Vegetal, Institut de Recerca i Tecnologia Agroalimentaries, IRTA, Crta. de Cabrils s/n 08348, Cabrils, Barcelona, Spain. C. Fernandez, and E. Alcaniz, Departamento de Patologia Vegetal, Institut de Recerca i Tecnologia Agroalimentaries, IRTA, Crta. de Cabrils s/n 08348, Cabrils, Barcelona, Spain; and A. Felipe, Servicio de Investi-gacion Agraria, Apartado 727, 50080 Zaragoza, Spain. Plant Dis. 80:754-757. Accepted for publication 26 March 1996. Copyright 1996 The American Phytopathological Society. DOI: 10.1094/PD-80-0754.

The effects of Pratylenchus vulnus on growth and nutrition of seven Prunus rootstocks were evaluated in two field microplot experiments. Plant materials were experimental rootstocks in advanced stages of selection or new commercial introductions into the Spanish market. In a first trial, fresh shoot weights, shoot lengths, and root weights of D-3-5 almond (Prunus dulcis), Nemared peach (P. persica), and the peach-almond hybrid (P. dulcis ? P. persica) G x N No. 9 were reduced in nematode-infested microplots compared with those in noninfested microplots at the end of the third growing season. Stem diameter was not affected by nematode infestation. In a second experiment lasting two growing seasons, most growth parameters were reduced in microplots infested with P. vulnus in Afgano (P. dasycarpa) and Myrobalan 29 C (P. cerasifera) plums, and in the peach-almond hybrid G x N No. 15. Damage was evident in the second year. Fresh top and root weights were reduced in Marianna GF 8-1 plum (P. munsoniana x P. cerasifera) at the end of the second growing season in nematode-infested microplots, whereas only shoot length was reduced in Nemared peach. No nutrient deficiencies were detected by foliar analysis in any of the rootstocks. Higher levels of phosphorus and zinc were found in P. vulnus-infested plants of G x N No. 15 than in control plants. All the tested rootstocks were good hosts for P. vulnus, which reached a high population density in the roots that fluctuated between 1,290 (G x N No. 15) and 5,311 (G x N No. 9) nematodes per g of root (fresh weight).

Keyword(s): pathogenicity, tolerance