RESISTANCE TO CAPNODIS TENEBRIONIS IN NEW PRUNUS ROOTSTOCKS

Abstract

Capnode (Capnodis tenebrionis L.) is one of the most important pests for stone fruits in the Mediterranean area, mainly in drought conditions. Among these fruit species, almond is very susceptible to capnode. Due to the biological cycle of the insect, the chemical control is difficult and the use of genetic resistance in plant material would be the definitive solution to this problem. In this work twelve Prunus rootstocks were tested against the grubs of capnode. Last year, ten plants of each rootstock were grown in the orchard, spaced 2 × 3 m, till the inoculation time. Adults of capnode were captured in the field, taken to small jails and feed with young apricot branches for two months. Capnode adults laid the eggs in the bottom of the jail in trays with sand. Weekly, the eggs were taken from the trays and 50 eggs were placed in the orchard soil (1 cm in depth) next to the trunk of each plant, in summer. Six months later, in winter, the rootstocks were pulled up to evaluate the presence of grubs and their damage in the roots. Most of the rootstocks were shown susceptible, presenting some grubs and different damage degrees. Only Rootpac-40 (Nanopac) and PAC 00-05 (AP 65) did not show grubs or damages in the roots. This could be a sign that they are resistant. These results must be double checked for two more years in order to accurately assess their level of resistance.