Isolation and Biological Control of Colletotrichum sp. Causing Anthracnosis in Theobroma cacao L. in Chiapas, Mexico

Anthracnose is a phytosanitary issue caused by various species of <i>Colletotrichum</i>. This study aims to revise the presence of <i>Colletotrichum</i> in the south of Mexico (the Soconusco area in Chiapas) and assess the inhibitory capacity of <i>Paenibacillus</i> sp. NMA1017 against <i>Colletotrichum</i> in in vitro and field experiments. The study involved sampling pods with anthracnose from 17 sites in the Soconusco area, Chiapas, Mexico. The incidence of the disease ranged from 0.6 to 11.63%. A total of 142 isolates exhibiting the morphological characteristics of the <i>Colletotrichum</i> genus were obtained. Fifty selected isolates were identified using the ITS region and were classified as <i>Colletotrichum gloeosporioides</i> with 99% similarity. The concatenation of morphological and physiological characteristics resulted in nine main clusters. The in vitro test showed that <i>Paenibacillus</i> sp. NMA1017 inhibited the fungal growth of selected strains by 30-50%. The field experiments included three commercial biocontrol agents, <i>Paenibacillus</i> sp. NMA1017, and a water control. The incidence of anthracnose (control with water) ranged from 32 to 65%, while the commercial biocontrol agents and <i>Paenibacillus</i> showed an incidence range of 12 to 20%. These findings support the use of <i>Paenibacillus</i> sp. NMA1017 as a biocontrol agent for cacao anthracnose.