Cocoa production in Ecuador in relation to dry‐season escape from pod rot caused by Crinipellis perniciosa and Moniliophthora roreri

Abstract

Cropping and disease patterns were observed over a period of 4 years in individual cocoa trees at three contrasting sites near Quevedo, Ecuador, with the aim of evaluating the importance of dry season production and the consequent avoidance of pod disease caused by Crinipellis perniciosa and Moniliophthora roreri. Distinction of the diseases on necrotic pods was aided by splitting open pods after removal from the tree. The year was divided into wet season (April to September) and dry season (October to March) harvest periods. The 3‐month lag between the actual wet and dry seasons and these harvest periods allowed time for symptom development. Combined disease losses ranged from 19·0% to 62·1 % at the various sites. At all sites and in each year, more ripe healthy pods were harvested in the dry season harvest period than in the wet season harvest period. In general, pod losses caused by C, perniciosa were curtailed more sharply by the dry season than those caused by M. roreri, which at one site caused as much damage in the dry season as in the wet season. The proportion of the annual production falling in the dry season harvest period varied among sites and between years at a given site. A comparison of trees from two progenies growing side by side showed consistent differences in cropping patterns, and identified certain trees that were productive, yielded consistently in the dry season harvest period, and were little affected by M, roreri. Analysis of long‐term rainfall data for the Quevedo region indicated that years which lack a normal dry season do occur, but only once every 10 years on average. Further exploitation of disease escape through selection and breeding appears to be both feasible and appropriate.

Effect of Fruiting Traits on the Field Resistance of Cocoa (Theobroma cacao L.) Clones to Phytophthora megakarya

“…This clone is also susceptible under conditions of high rainfall. Studies on escape mechanisms of diseases caused by Moniliophthora roreri and Crinepellis perniciosa were carried out in the main cocoa‐growing region of Ecuador (Maddison et al., 1995). For both diseases, the protracted dry season gives opportunity for pods to ‘escape’ disease by forming and maturing under much‐reduced risk of attack.…”

A disease and production index (DPI) for selection of cacao (Theobroma cacao) clones highly productive and tolerant to pod rot diseases

“…From the weather data, the bimodal weather pattern (Cedeño et al ., ) of the coast of the Ecuador location is revealed. The weather varied between years, something expected to influence subsequent fruit set, disease, and yield (Maddison et al , ). Rain typically falls between November and May, during which most cacao trees flush, flower, and set fruit.…”

Moniliophthora perniciosa, the causal agent of witches’ broom disease of cacao: what's new from this old foe?

“…Moniliophthora perniciosa is also responsible for one of the main pod rotting diseases of cacao, previously know as Crinipellis pod rot (Maddison et al ., 1995) (Fig. 2D,E).…”