Tarqui-Freire, Omar Miguel, Ignacio A Sotomayor-Cantos, T Casanova, G Rodríguez, L Plaza & Zambrano 2017
Selection of Cocoa Genotypes (Theobroma Cacao L) Resistant to Witches’ Broom Disease (Moniliophthora Perniciosa) in Los Ríos, Ecuador. Ciencia y Tecnología, 10: 17–26
Notes
Results from trials to identify and select cocoa clones having a low incidence of witches broom disease. Progenies were created in crossing schemes based on Upper Amazon x Upper Amazon (A), Nacional x Upper Amazon (B), National x National (C), and CCN 51 x Upper Amazon (D) and seedlings evaluated for field incidence of Witches' Broom under heavy natural inoculation pressure. Promising individuals were propagated and planted in trials together with clones TIP 1 and TAP 6 as controls (four repetitions, with three plants per clone in each repitition) and using EET 109 as borders. The following data were recorded at harvest (15 day intervals) between December 2007 and November 2013: Number of healthy pods, Fresh weight beans per tree, Number of Witches Broom infected pods, Number of vegetative brooms, Number of Witches' Broom infected flower cushions and Number of chirimoya fruits (pathenocarpic fruits). A Principal Components Analysis and a cluster analysis were performed using the Ward method and a dendrogram was constructed to determine the similarity between productive and disease resistance characteristics, and three groups were identified. Genotypes resulting from the Amazonian x Amazonian crossing: INIAPT 527, INIAPT 560 and INIAPT 526 were found to have the lower levels of Witches Broom disease with good productivity.