The influence of management and plantation characteristic variables on witches' broom disease intensity level and cocoa bean production in Rondônia, Brazil. In: Agrotrópica v. 4 p. 45-52, 1992.

Abstract

The Brazilian state of Rondônia produces an amount of cocoa with an estimated worth of US$ 12 million annually. This levei of production ranks Rondania second only to Bahia for cocoa production in Brazil. However, tbe fungaI disease Witcbes' Broom severely limits cocoa production in Rondônia. This study represents an attempt to quantify the factors that are involved in increasing the disease intensity leveI' of Witches' Broom on a cocoa plantation. This was achieved by the development of a statistical model. A similar approacb was used to identify the factors which influence cocoa production at the plantation leveI. The models were based on data for the município of Ouro Preto do Oeste in Rondônia. The models show that control of Witches' Broom is the singIe most important fact influencing the probability of the bigbest Witcbes' Broom disease intensity levei occurring on a plantation. Control, aIong with disease intensity leveI, was also an important variable in predicting cocoa bean production. If control of the disease is attempted, production per hectare of cocoa increases. In addition to control, other management, plantation characteristic, anel locational variables were important factors influencing both the probability of high disease intensity and production.