Back H. Tokeshi and P. R. R. Chagas
USP-ESALQ, 13419 900, Piracicaba, Brazil
Full Paper (PDF File: 100KB)
Abstract
The energy supply of seeds decreases during germination, exposing seedlings to pathogen attack. The survival probability increases if the period of germination is reduced. The potential of seedling survival is called vigor, which is measured by emergence speed and is used to estimate the potential of success in the field. Knowing that effective microorganisms (EM) have hormonal action as gibberellic acid, the emergence speed was evaluated in tangerine cv. Cleopatra treated with metalaxyl (1.05 g. a.i./kg of seeds) as control, in comparison to EM 0.1 % v/v per 30 minutes and weekly spray 0.05 % v/v. A sterilized substract and non-contaminated water were used in the whole experiment with 108 replications and 13,824 seedlings per treatment. The emergence speed of the EM treatment was superior to the control and the percentages of vigor increase were 810 %, 944 %, 646% and 552% at 20, 21, 22 and 23 days, respectively. The hormonal effect of EM was superior during the initial 4 days of emergence. The effect of vigor increase on seedling growth was evaluated on the 40th day of seeding and showed statistically (p < 0.01) that EM produced larger plants than the control.