Hybrids of Zea mays L. (Buffalo, Falcon, H360 y HV313) were treated with citric acid(2000 ppm). The grain yield, the soluble protein and the proteolytic activity were monitored in thephysiological maturity stage of the crop. The citric acid was applied before the appearance of theflag leaf, induced an increase in the production of the grain from 540 to 945 kg?ha-1, in the solubleprotein from 1.39 to 4.2 mg?mg d?w-1 and into the proteolytic activity from 2 to 12 times in theFalcon, H360 and HV313 hybrids, while the Buffalo hybrid responded with less intensity to thetreatment with citric acid. In the H360 hybrid treated with citric acid, an increase in the proteolyticactivity of aspartyl serine proteases was observed. The results indicate that citric acid inducesdifferentially, the proteolytic activity and the vigor of the corn hybrids analyzed.
corn, citric acid, proteolytic activity.