Seed viability is strongly influenced by storage conditions. In weeds, this information may serve as support for other research works and help to understand infestation dynamics as well. This work, conducted at Universidade Federal de Lavras, was carried out to evaluate the viability of coat button (Tridax procumbens) seeds stored in cold chamber ( temperature of 10 ºC and relative humidity of 50%), in freezer (-18 ºC), conventional warehouse (uncontrolled conditions) and soil, over 2 years. Seed lot with 70.5% initial viability, maintained this condition over the experimental period (730 days) when stored in cold chamber (in paper bags) and in freezer (in airtight plastic tubes). Under soil conditions, viability loss occurred with time, at a constant rate of 8.2% at every 100 days. In a conventional warehouse, seed lot viability (in paper bag) was maintained for 200 days but there was a fast reduction between 300 and 500 days, and at the 730 days end only 2.8% of the seeds were viable. In none of the storage forms, there was induction of secondary dormancy in seeds.
Tridax procumbens; weed; longevity; seed bank
