Glasshouse method for screening seedlings of cocoa Theobroma cacao L for resistance to black pod caused by Phytophthora palmivoraButl Butl

A new method for screening cocoa seedlings for resistance to black pod caused by the fungus Phytophthora palmivora (Butl.) Butl. is described in which pregerminated seeds are inoculated with a culture of the fungus. Seedling mortality at eight weeks appears to be related to the susceptibility of the parents to black pod in the field. Unlike previous methods for testing resistance, the new method may make possible the screening of large quantities of seedling progenies from clones with known field resistance, leaving relatively resistant seedlings for field planting. The method offers prospects for studying the genetics of black pod resistance.