Levantamento das doenças bióticas e abióticas que ocorrem em Tectona grandis L. f. no estado de Mato Grosso

Abstract

The forest species Tectona grandis L.f, popularly known as teak, native to the Asian continent, more specifically India, Myanmar, Thailand and Laos. Its wood is known worldwide for its characteristics of workability, density, strength, stability, durability and its natural beauty. Due to the prohibition of extraction in its native area and the value added to the wood the area planted with teak has been expanding around the world. There are now more than 6.8 million hectares planted worldwide. In Brazil, teak farming began in the 1970s, and due to favorable climatic conditions, properly adopted silvicultural treatments and adapted genetic material have reached a productivity > 15m³ / ha / year in a 20-year cycle. Along with the expansion of the species, the problems of biotic and abiotic origin appear, still little studied for this culture. Thus, in order to identify the diseases that affect the productivity of teak in the state of Mato Grosso, collections were carried out in four municipalities of the state (São José dos Quatro Marcos, Sinop and Várzea Grande). Eighteen samples were analyzed, including stem, leaf and root samples, as well as field inspections and area history studies. From macro and microscopic analyzes, it was possible to diagnose that 14 samples were of biotic and four abiotic origin diseases. The pathogens found associated with biotic diseases were Cercospora sp., Cladosporium sp, Colletotrichum sp., Xanthomonas sp. and Myrothecium sp. associated with leaf spot, Myrothecium sp. Causing rot of cuttings, Kretzschmaria zonata, Curvularia aeria and Fusarium solani associated with root rot, Ceratocystis fimbriata causing vascular wilt and Olive neotectonae causing rust in teak. Among the biotic diseases that deserve more attention are keratocystis wilt by Ceratocystis fimbriata, root rot caused by Kretzschmaria zonata and teak rust by Olivea neotectonae, as they are more frequent and cause great economic losses. The abiotic diseases detected were: incidence of winds causing tree breakage, phytotoxicity, nutritional imbalance and lightning incidence. In view of these results, it is clear the need for more phytopathological studies for the culture, as well as the importance of developing genetic materials resistant to these diseases.