Effect of Endophytic Trichoderma sp. Strains on the Agronomic Characteristics of Ecotypes of Theobroma cacao L. under Nursery Conditions in Peru

Abstract

Expanding its territory greatly in recent years, Peru has become one of the primary producers of exquisite aroma native cacao. As a result, it is vital to search out sufficient management choices to generate beneficial yields. The purpose of this study was to examine, in a controlled environment in the Cajaruro area of Utcubamba, Amazonas, Peru, how endophytic strains of Trichoderma sp. affected the agronomic traits of Theobroma cacao L. ecotypes. Ecotypes CCN51, TCHS565, and Nativo fino de aroma cocoa seedlings were infected with the following Trichoderma strains: T. breve, T. harzianum, T. longibrachatum, T. afrojarzianum, and Trichoderma sp. Agronomic traits (such as plant height, number of leaves, stem diameter, root dry and fresh weight, root size, etc.), chlorophyll indices (at30,45,60, and 70 days after planting), root hair growth, trichomes on stems, and percentage of endophyte colonisation were among the factors examined. In the study, it was found that Trichoderma breve had the best effects on the number of leaves (12.00 ± 3.46), percentage of colonisation in the root hairs (66.67%), and the highest chlorophyll index at 75 days after planting (DAP) for the apex and leaf base, respectively, when applied to the fine aroma native cocoa ecotype (T12). Chlorophyll index, plant height, and the number of leaves were all positively affected by T12. Two treatments, one based on T. harzianum and the other on T. afroharzianum and TSHS565, resulted in complete colonisation of the root hairs and stem trichomes. An alternative to conventional methods, endophytic Trichoderma fungus enhance the agronomic traits of excellent aroma cocoa grown organically in Peru.