Potencial fisiológico de sementes de alface submetidas a diferentes tratamentos físicos para controle de patogénios

Abstract

Plant propagation through seeds can be a source of disease transmission, so the use of seed treatment methods is of paramount importance. The objective of this study was to evaluate the physiological and sanitary potential of different batches of lettuce seeds submitted to physical treatment methods. Thermotherapy and exposure to ozone gas were tested for 100 and 200 minutes. The efficiency and level of physiological damage caused by the treatments were evaluated by germination, accelerated aging, length, dry mass, total emergence, emergency speed index (LVI), and health (Blotter test) tests. The experimental design was completely randomized with four replications, and the results submitted to analysis of variance and Tukey test at 5% probability. Thermotherapy increased lettuce seed germination and accelerated the formation of normal seedlings with higher dry mass of shoots and roots. Both ozone treatments accelerated germination speed and root formation. Exposure to ozone for 200 minutes increased the shoot dry mass. The heat treatment was efficient in the control of Alternaria sp. Fungus, however favored the development of Aspergillus sp.