Resumo

GARCIA CRESPO, Rosaima G; ARCIA MONTESUMA, Miguel A.; PEREZ TORTOLERO, Miguel R  e  RIERA TONA, Ramón F. Effect of Trichoderma on potato development and biocontrol of Rhizoctonia at three times from applying. Agronomía Trop. [online]. 2012, vol.62, n.1-4, pp.077-096. ISSN 0002-192X.

Rhizoctoniasis caused by the fungus Rhizoctonia solani Kühn, decreases potato yield. Seeking for environmentally and friendly alternative management of the disease, this study was conducted to evaluate the effect of Trichoderma on development of potato, Solanum tuberosum L. and biocontrol of R. solani in the seed production process. Two replicas of a test cultivation house at Campo Experimental Mucuchíes, INIA-Merida were performed, under completely randomized design, where the application of three strains of Trichoderma asperellum (M-4, M-11, M-18 and their mixture) on potato plants cv “Andinita” was evaluated initiating at three different times: seed, furrow at planting and emergence of plants. Trichoderma treated plants showed significant increases in physiological variables (growth, photosynthesis) and yield; with low incidence, severity of injury and rhizoctoniasis reduction in tubers, maintained at all stages of development. The best responses were obtained with M-11 and the mixture, when the application is started in the emergence of plants, low incidences that were reached at 2.23 and 3.9%, grade 1 severity of injury, disease reduction 83 and 80%, respectively, higher yields, ranging from 77.000 a 83.333 kg ha-1, compared with the control. The endophytic strain M-11 T. asperellum represents an alternative for the management of potato rhizoctoniasis crop for seed.

Palavras-chave : Solanum tuberosum; management; seed; physiology.