The dry heat treatment aiming to control microorganisms in the seeds can cause damage to the physiological quality of seeds. Osmotic conditioning can be useful tool for recovering the physiological quality of the heat treated seeds. The study was carried out to evaluate the effects of dry heat treatments on the tomato seeds sanitary and physiologic quality, as well as to analyze the effect of the osmotic conditioning on seeds submitted to dry heat treatment. The seeds of cultivars Quadrado Mix, Topmec and Calmec VFN were heated at 70; 72.5 and 75ºC by periods of zero, 48; 96 and 120 hours. After the heat treatment, the seeds were evaluated for the presence of pathogens and were submitted to the osmotic conditioning using polyethylenoglicol in the 0.0 and -1.0 MPa osmotic potentials. Seed moisture content, germination test and vigor tests were performed. The dry heat treatment did not eliminate the microorganisms in the tomato seeds, depending on variety evaluted. The prolonged periods of dry heat treatments caused severe seed damage and the osmotic conditioning treatment was not able to improve the seed quality.
Lycopersicum esculentum; thermoterapy; seed health; germination
