Control biológico del añublo sureño (Sclerotium rolfsii L.) en frijol (Phaseolus vulgaris L.) con Trichoderma harzianum R. y tres biopreparados como enmienda al suelo y tratamiento a la semilla

Abstract

The research was conducted in the laboratory and greenhouse of the Department of Plant Protection of the Faculty of Agricultural Sciences, University of El Salvador, from September 2016 to May 2017, the effectiveness of control of three biopreparados was evaluated (lombriabono, bocashi and mountain microorganisms), an antagonist Trichoderma harzianum (Excalibur Gold®), a relative control Copper Hydroxide (Kocide WG ®) and an absolute control in two application methods (soil amendment, seed pelletizing), on the phytopathogen Sclerotium rolfsii L. causative of southern blight disease in beans. A trial was carried out with 11 treatments and 5 repetitions, plus a duplicate, the culture was carried from planting to the first month in the greenhouse, inoculating the phytopathogen in sterile substrate, taking emergency data and infection in seed five days after sowing, and then every three days to measure the level of infection in plant. The methods of application had an influence on the control of beans seed infection by S. rolfsii L. (X1 = 93.96% p= 2.2x10-16). The lowest percentage of probability was soil amendment (2.5%, EE = 0.60), suggesting that this method reduces the effects of infection. The evaluation in application of products showed differences for infection in seed (X4 = 62.52, p <8.55x10-13), being Trichoderma harzianum (Excalibur Gold FS®) applied pelleted the one that presented lower percentage of infection (4.5% EE = 3.2%). There were strong effects of interaction between products and forms of application, for emergence (X4 = 48.921 p= 6.066x1010), infection in seed (X4 = 32.894 p= 1.256x106) and bean plant infection (X4 = 15.6784 p= 0.003483).