Hybrids of Zea mays L. (Buffalo, Falcon, H360 y HV313) were treated with citric acid (2000 ppm). Grain yield, soluble protein and proteolytic activity were monitored when the crop reached physiological maturity. Citric acid was applied before the appearance of the flag leaf, and induced an increase in the grain yield from 4222 to 5780 kg/ha, in the soluble protein from 6.34 to 7.91 mg/mg and into the proteolytic activity from 14.3 to 65.7 µU mg prot-1. This is an increase of 2 to 12 times in the Falcon, H360 and HV313 hybrids, while the Buffalo hybrid responded with less intensity to the treatment with citric acid. In the H360 hybrid treated with citric acid, an increase in the proteolytic activity of aspartyl serine proteases was observed. The results indicate that citric acid differentially induces proteolytic activity and vigor in the corn hybrids analyzed.
Maize; citric acid; proteolytic activity
