Combining ability of superior cacao clones for assembling high productivity and disease resistant cocoa

This research aimed to determine the potentiality of P1 and P2 as parents to produce superior strains of hybrid cacao by estimating general combining ability (GCA) and specific combining ability from crossed diallel among high yielding parents which are resistant to P. palmivora. The study was conducted at the Experimental Farm Sumber Asin, Malang, East Java, from 2010 to 2018. The research was arranged in Randomized Block Design (RBD) consisted of 10 hybrids and 5 parents so that the treatment used 15 genotypes. Each treatment consisted of 12 plants in triplicates. Resistance test on parents and F1 showed that all crossed combination strains were infected by pod rot disease (P. palmivora) with various intensity. The highest disease intensity was a strain combination of DR 1 x ICS 13 and the lowest one was ICS 13 and SCa 6. All crossed combination strains in the field had not shown symptoms of any pest infection. Cacao clones that have low GCA value based on the disease intensity were TSH 858, ICCRI 3 and SCa 6. These clones have the potential to be used in the assembly of disease-resistant and high-yielding cocoa hybrids in the future.