The present work was aimed at evaluating inoculation methods of Phytophthoraparasitica on citrus (Citrus spp.) seedlings and young plants to determine the resistance of citrus rootstocks to Phytophthora gummosis. The following inoculation methods were tested: non-wounded host-pathogen contact, bark removal, insertion of culture disc under bark, insertion of inoculated needle or toothpick in the collar region and, the culture disc method. The assessment of resistance to gummosis in citrus seedlings produced in vitro was achieved by inserting an inoculatum in collar region. The disc method and insertion of disc under the bark were the best inoculation methods for young plants under both orchard and greenhouse conditions. The best variable for disease assessment had been the measurement of the total lesion area. Lesion length can also be used when carried out in nurseries and in the field.
