Microbiolização em sementes de feijão-fava

Abstract

The fava bean (Phaseolus lunatus L.), also known as fava beans or lima beans is one of the species belonging to the family of Fabaceae and the genus Phaseolus. The seeds are the main means of propagation of the crop, being of fundamental importance that they have high genetic, physical, sanitary and physiological quality. Thus, the present work aimed to evaluate the effect of different concentrations of Trichoderma asperellum and Saccharomyces cerevisiae on the quality of fava bean seeds of the varieties "Cara larga" and "Orelha de vó". The seeds were initially disinfested, and later, being immersed for five minutes, in the treatments: (T1) - Witness (sterilized distilled water – ADE); (T2) - Captan® Fungicide (240 g/100 kg of seeds); for the concentrations of Tricho-turbo®, a product based on T. asperellum, (T3) - 0.8 mL L-1 , (T4) - 1.7 mL L-1 , (T5) - 2.5 mL L-1 and (T6) - 3.3 mL L-1 , diluted in ADE - (I). (T1) - Witness (sterilized distilled water – ADE); (T2) - Captan® Fungicide (240 g/100 kg of seeds); for the concentrations of SAF-INSTANT, product based on the dry yeast of S. cerevisiae, (T3) - 0.5 g/L, (T4) 1.0 g/L, (T5) - 1.5 g/L and (T6) - 2.0 g/L, diluted in ADE - (II). The health test was composed of 100 seeds, in 10 replications with 10 seeds for each repetition. The seeds were incubated in Petri dishes (9 cm) with a double layer of sterile filter paper moistened with ADE. In the germination test, the seeds were sown on previously sterilized Germitest® paper. Being composed of 100 seeds, being four replicates of 25 seeds for each treatment. The emergency test was performed in a greenhouse, composed of 100 seeds, with four replicates of 25 seeds for each treatment, then sown in tubes with sterile sand and watered daily. The concentrations of 0.8 mL/L, 1.7 mL/L and 3.3 mL/L of T. asperellum reduced the incidence of Aspergillus spp.. Thus, T. asperellum is efficient in inhibiting fungi and promoting plant growth, but reacts in different ways depending on the dosages and environmental conditions it is exposed to, making further studies necessary to identify the best condition to be used. The percentage of first count for the Cara larga variety was higher in the concentrations of 1.5 g/L and 2.0 g/L of S. cerevisiae, with 80%, being higher than the fungicide that presented a percentage of 35%. S. cerevisiae was efficient in seed treatment, which allows it to be used as a substitute for the use of fungicide.