Trichoderma asperellum increases crop yield and fruit weight of blackberry (Rubus glaucus) under subtropical Andean conditions

Mora de Castilla (Rubus glaucus, Benth), also called blackberry, is grown mainly in Colombia and Ecuador. This fruit crop is of economic importance for farmers in the Province of Tungurahua (Ecuador). In this field research, the effect of Trichoderma asperellum (1.53 × 109 CFU/g) inoculation was assessed on crop yield and fruit weight at three production sites (Huachi Grande, Pillaro and Tisaleo in Ecuador). Factorial experiments were conducted consisting of treatments of 0.18 g of a commercial product per plant and a second uninoculated treatment). The product was applied eight times per month and the weekly fruit harvest recorded in each of the eight applications. The inoculation of T. asperellum had a significant effect on crop yield and fruit weight: yield was greatest in Tisaleo (5350 g/plant) with T. asperellum treatment, which was increased by 17% over the uninoculated witness (4447 g/plant). Fruit weight in Pillaro was improved from 5.36 g/fruit for the uninoculated control to 6.04 g/fruit (12.6%). Additionally, the organic matter (OM) content was correlated with the fungal population in the soil. Tisaleo had the highest OM (4%) and the highest yield in this study. In conclusion, the inoculation of T. asperellum in the soil positively affected crop productivity.