Control techniques and evaluation of pathogen influence on African mahogany (Khaya grandifoliola C. Dc.) infected by Lasiodiplodia theobromae Pat.

Abstract

The constant demand by society for quality timber associated with reduced exploitation of native forests has promoted the use of alternative species such as the African Mahogany (Khaya grandifoliola C. Dc.). The production cycle of this species began with the introduction of seeds in the 1970s and good silvicultural performance of the first planted matrix trees, then spreading throughout several Brazilian regions and resulting in increased occurrence of pest insects and diseases, such as African mahogany canker (Lasiodiplodia theobromae Pat.). In this context, this work aimed to identify control methods and to analyze the damage caused by canker in symptomatic African mahogany trees. Scraping and chemical treatments were carried out in different concentrations to analyze the best method to prevent an increase of lesions caused by the pathogen. The anatomical characteristics and basic density of wood with and without canker were evaluated. It was observed that scraping until reaching the healthy tissue is an effective method of control which stimulates the healing process after a certain period. For the chemical treatment without scraping, Nativo® fungicide is efficient through direct application. The presence of canker promoted an increase in wood density and changes in anatomical characteristics.