The cold test has been employed mainly for corn seeds but its use is steadly growing for crops as cotton, soybean, common bean, pea, etc. It seems also to be true that for each of these crops the procedures of the cold test should be standardized. Thus, seed vigor of five cotton delinted seed lots was evaluated by means of different procedures of the cold test: soil plastic boxes, soil in rolled paper towel and rolled paper towel without soil. Seeds were exposed to 10°C during three, five and seven days. Simultaneously, seeds were submitted to the electrical conductivity and the accelerated aging vigor tests to make a comparison with the cold test. The paper towel method for five and seven days allowed, consistently, the detection of different vigor classes of seed lots when compared to the other cold test procedures as well as to the electrical conductivity and accelerated aging tests. The use of the paper towel as substratum and the exposure of seeds to 10°C for five days is therefore indicated as a reliable method for cotton seed vigor evaluation.
Gossypium hirsutum; seed analysis; physiological quality; cold test