Fusariosis incited by Fusarium guttiforme is the main limiting factor for pineapple cultivation in Brazil and
other South American countries. Disease management based on biological agents is desired because resistant varieties are not yet widespread through the producing areas and there is no information on the
durability of the resistance. Fungicide application has led to the selection of resistant populations of
the fungus in the field, besides the negative effects of these chemicals on human health and the environment. Because pineapple cultivation is expanding in the Caatinga biome, this study is an attempt to
employ Trichoderma species isolated as endophytes of plants from this region, which is characterized
by low precipitation and high temperatures. A total of 109 isolates of Trichoderma were obtained from
the sapwood of four plant species: Ananas comosus var. bracteatus (Bromeliaceae), Astronium fraxinifolium
(Anacardiaceae), Bowdichia virgilioides (Fabaceae) and Caesalpinia pyramidalis (Fabaceae). The 109 isolates
were clustered in 11 BOX groups and one isolate of each group was identified by sequencing the ITS and
tef-1a regions. The isolates were subjected to a series of experiments in vitro in Petri dishes and pineapple
stalk discs, and in vivo in a greenhouse and in the field. The number of isolates showing ability to inhibit
the pathogen and control the disease at levels higher than 80% was 26 in Petri plates, 21 in stalk discs, and
3 in the greenhouse and field assays. These three isolates were consistently able to decrease disease
severity by 68–84% across two field experiments.