The phytosanitary pruning effect on the witches' broom disease in the cocoa farming

Abstract

The witches’ broom disease in the main phytosanitary problem of cocoa and its management is a function of pod removal, however, their efficiency is subject to application time. The aim was to establish the right time in summer season. Pruning the plant was studied in two months in the summer season. The first in August (1-15) and the second in December (1-15). Clones 575 and 576 of 15 years cocoa with a planting density of 1111 pl.ha-1 was used as experimental material. The life cycle of Moniliophthora perniciosa was identified: inoculation, incubation and infection, taken the time in days for each stage. Furthermore, after the pruning infections, bearings and ears were counted, and thus the average number of infections per tree was obtained. Between 10 and 15 January sporulation of the fungus starts. The presence of symptoms was observed 45,6 ± 0,9 days after sporulation. The parasitic phase was 39,4 ± 9,22 days and total necrosis was 10,11 ± 3,4 days. After the phytosanitary pruning in August, new formations of M. perniciosa were able to form basidiocarps in subsequent winter season. In December the fungus were not capable of forming basidiocarps. The evidence shows the influence of plant pruning in December on the biological cycle of M. perniciosa and infestation levels of cocoa.