Vigor tests as a function of harvest time of barley (<i>Hordeum vulgare</i> L.) seeds

Abstract

The study was performed in the Seed Technology Laboratory at the Federal University of Pelotas (Pelotas – RS), with the purpose of evaluating the physiological quality of barley seeds (Hordeum vulgare L.) harvested in different times. The experiment was carried out with seeds of barley varieties NM 721 and Scarlett. The seeds were harvested at 118, 129 and 140 days after sowing, when the relative humidity was below 30%. The seeds were dried in a forced circulated air oven to reach a moisture content of 13% and then stored in a cold room at 17 °C and 35% relative humidity for 18 days. The quality of seeds was assessed using the standard germination test, tetrazolium test, was thousand-seed weight, hectoliter weight and electrical conductivity test. These tests were performed at constant temperature of 20 °C in different soaking periods (1, 3, 6 and 24 h). The statistical procedure were in a completely randomized design, with four replications and a 2 x 3 factorial scheme. The results showed the higher performance of the heavier seeds in relation to the lighter seeds. Tests for germination, tetrazolium and hectoliter weight tended to decrease according to the delay in the harvest time. The use of the electrical conductivity test allowed identifying damages caused by the process of seed harvest in different times.