The cold test for evaluating maize seed vigor is usually performed in plastic deep-boxes (47 x 30 x 11cm) filled with approximately 16 kg of sand/soil mixture. This study was conducted to verify the influence of prechilling the substrate in the cold test and of the arrangement of deep-boxes inside the cold room (stacked or placed side by side). These factors are not yet completely defined and contribute significantly to variations in cold test results in Brazilian seed laboratories. Maize seeds were submitted to three treatments: substrate and water without prechilling (T1); water prechilled to 10ºC before planting (T2) and substrate and water prechilled to 10ºC before planting (T3). Four deep-boxes of each treatment were stacked and 4 were placed side by side in the cold room. Prechilling of substrate inside the cold room was monitored by evaluating the substratum temperature at 2, 4, 8 and 26 hours after planting. After 7 days in cold chamber, the boxes were transferred to the laboratory (± 25ºC) and the germination was recorded 7 days after transfering. Results showed that the alternative "substrate and water prechilled to 10ºC (T3)", placed side by side, provided uniform conditions for the cold test in maize, producing more consistent results.
cold test; Zea mays L; substrate; methodology
