Archivio Journal of Plant Pathology

Abstract:

Frosty pod rot of cocoa, induced by Moniliophthora roreri. has become the principal parasitic limitation for cocoa production in Tabasco (Mexico), which has prompted studies on its temporal progress and management. The temporal progress was desumed from estimation of the percentage of diseased fruits in three fruit flushes in the production cycle of 2008-09, whereas a regional management was compared with an Integrated Crop Management (ICM) in two systems of shade (50 and 70%). Three epidemics occurred from May 2008 to April 2009 with crop losses of over 70%. The epidemics occurred during 11 consecutive months associated with cool temperature (20-26.9ºC) and relative humidity (higher than 90%) 49 days prior to the appearance of the symptoms. The ICM treatment with 50% shade showed a protection effectiveness of 90%. The reduction of shade to 50% alone reduced the incidence of frosty pod rot by 20%. The results suggest the convenience of independent management of the epidemics and the advantage of the following integrated control measures in each of the three fruit flush periods: weekly removal of diseased fruits, pruning of lateral and internal branches, reduction of tree height to 4 m, total elimination of fruits in low production period (purge), treatment of eliminated fruits and harvested litter with 15% urea, a single application with Azoxystrobin (250 g a.i./ha) to fruits under two months of age, and after it, three monthly sprays with copper hydroxide (1500 g a.i./ha). Additionally, weed control and improvement of soil drainage were implemented in both ICM and regional treatments.