Resumo

MANCERA RICO, Arturo et al. Fracture resistance and physiological quality of corn seeds under axial compression. Rev. Mex. Cienc. Agríc [online]. 2016, vol.7, n.1, pp.45-57. ISSN 2007-0934.

The physical, physiological and sanitary qualities of corn seeds are reduced due to the mechanical damage caused by the mechanization of the production process. Knowing the strength and displacement critical values according to the type of endosperm will help decrease the damage during the cleaning, drying, storing and handling processes. This study assessed the strength and displacement from compression, the visible damage and the physiological quality of corn seeds from the following varieties: Cacahuacintle (floury), HS-2 (semi-floury) and Popcorn (hard) considering a humidity of 12 and 20%. The percentage of soft endosperm in Cacahuacintle, HS-2 and Popcorn was 76.20, 33.43 and 15.27%, respectively, while the percentage of hard endosperm was 5.25, 48.93 and 65.21%, respectively. The displacement and the strength for the Cacahuacintle variety was 0.8264 mm and 274.71 N, for the HS-2 variety was 0.5499 mm and 309.07 N and for the Popcorn variety was 0.5066 mm and 356.29 N, while for 12 and 20% humidity it was 0.3279 mm and 312.52 N and 0.9520 mm and 313.81 N, respectively. The damage indexes in compressed seeds were 276.67, 327.78 and 220.01 for Cacahuacintle, HS-2 and Popcorn, respectively, while for uncompressed seeds (control group) the damage indexes were 0.00. Germination was 85.20% for uncompressed seeds and 55% for those seeds subjected to fracture. The damage index was affected by the variety and the compression, but not by the humidity. Germination was not affected by the damage index, but it was affected by humidity and compression.

Palavras-chave : Zea mays L.; crystalline; endosperm; floury; mechanical damage.