Sanitary and physiological quality of ‘purple’ corn (Zea mays L.) seeds submitted to thermotherapy

ABSTRACT: The use of seeds with good sanitary and physiological potential ensures the establishment of the crop, with a uniform, vigorous and disease-free seedling stand, which will result in good productivity levels. Seen that, the objective was to evaluate the sanitary and physiological quality of purple corn seeds (Zea mays L.) submitted to thermotherapy. They were subjected to heat treatment with immersion in sterile distilled water (SDW) heated at 50, 60 and 70 °C for 1, 2, and 3 minutes. The control (0 min) correspondens only to immersing the seeds in SDW, which were submitted to sanitary and germination tests in a completely randomized experimental design, in a factorial arrangement 3 × 3 + 1 (exposure time × temperature + additional control). Data were subjected to analysis of variance, and the means were compared with the Scott-Knott test up to 5% of probability, with the aid of the statistical program SISVAR®. Immersing Zea mays seeds in hot water at 50, 60 and 70 °C for 1, 2, and 3 minutes is efficient to prevent the increased incidence of Aspergillus sp., Penicillium sp., and Fusarium sp. The heat treatment at 60 °C for 1 and 2 minutes of immersion reduces the incidence of fungal mycoflora without impairing the physiological quality of seeds.