Control de Rhizoctonia solani Kühn en tomate (Lycopersicon esculentum) con el hongo Trichoderma harzianum

The disease “Damping off” caused by Rhizoctonia solani, causing of the necrosis in the stem of tomato seedling, it is one from the main problems to level of seedling. The objective was to evaluate the control of Rhizoctonia solani in tomato, incorporating Trichoderma harzianum to an organic substrate. Tomato seeds were sowed in seedbed with the organic substratum that contained the biocontrolador to reason of 50g/25 Kg substratum. They conformed to four treatments for a total of 400 seedlings and the population of T. harzianum was determined in four samplings, taking sample from the substratum to 3 cm of depth. The incidence of the disease was evaluated and the height, fresh weight was determined and I dry off of the air port and fresh weight of the roots. The population growth was sustained, not presenting signifi cant differences (P>0,05) where was applied, while if there are signifi cant differences with regard to the treatments where it was not applied (P <0,05). The presence of the disease was detected starting from the ninth day, presenting the biggest incidence in the witness with 32% of sick plants. The obtained results indicate that the combined presence of the organic substratum and T. harzianum still limit the appearance of the disease existing the pathogen in the fl oor and it stimulates the multiplication of this biocontrolador, increasing the vigor of the plants, what suggests that this biocontrolador can be an employee for the control of the well-known disease as “Damping off” in the cultivation of the tomato that is caused by Rhizoctonia solani.