Trichoderma application increases yield and individual fruit weight of blackberries grown by small farmers in Ecuador

The Castillian blackberry "mora" (Rubus glaucus) is a native blackberry grown in Ecuador by small farmers, but yields are low due to inefficient management and disease. As part of a program to improve yields, we applied a Trichoderma asperellum granular formulation to plants in farmers' fields. Trichoderma spp. fungi are well known as antagonists against pathogenic fungi and as growth promoters in plants, but few studies have been carried out in perennial fruit crops. In the present study, 5 g of Trichoderma asperellum granulated formulation (1x108 conidia g(-1)) was inoculated into the soil at the base of the plants on three farms in the temperate valleys of the Ecuadorian Andes (2800-3000 m a.s.l.). Over a period of 9 months, fruit was harvested weekly with yield, individual fruit weight, and vigor of the plant recorded. Plants treated with Trichoderma sp. had an average yield of 973 g plant-1 month-1, significantly higher than the control of 689 g plant(-1) month(-1). The weight of the fruit also turned out to be higher on average in the plants treated with Trichoderma sp. (6.3 g fruit(-1)) compared to their controls (5.2 g fruit(-1)) The phenomenon occurred in the three locations studied, observing an increase of 26.1%, thus improving the quality of the fruit. The populations of Trichoderma in the soil after 30 days of application were significantly different with respect to the controls in the three localities, which is evidence of a persistence of the fungus in the soil over time. There were significant differences in yield and fruit weight with respect to the type of soil (p<0.05) positively associated with the content of organic matter.