Effects of the application of Trichoderma asperellum and its culture filtrate on the growth of onion seedlings

Abstract

The application of Trichoderma spp in onion has focused mainly on the fight against diseases such as Sclerotium cepivorum, its principal phytopathological problem. With the application of biocontrollers, we seek to reduce the use of chemical fungicides and to prepare the plant from the first stages of the seedbed with the application of culture filtrate that strengthen and colonize the root providing a protection against the attack of pathogens. The objective of this research was to determine the effects of a native strain of Trichoderma asperellum and a secondary metabolite culture filtrate on the growth of onion seedlings (Allium cepa). The research was made in two different years: 2015 and 2016. Each treatment consisted of 2 trays, each with 288 plants: T 1 = T. asperellum prepared at 100%, T2 = T. asperellum prepared at 50%, T3 = Vitavax commercial product ®, T4 = Control, T5 = 100% filtered and T6 = 50% filtered. In 2015 were tested only the first four treatments. By 2015, it was observed that T1 is the best treatment, as it showed a greater effect on elongation and dry weight as well as on fresh root weight and aerial dry weight. In the elongation of the root for 2016, the T2, T1 and T6 treatments presented the largest sizes. Based on the observed, treatment of 50% filtrate has the same effects as treatments T1 and T2 in all variables.