The objective of this study was to develop a method to determine corn grain resistance to mechanical damage. Seven hybrids were evaluated: AS1535, AS1570, AS1575, AS3430, AG7000, P30F80, and DKB390. The impact imposed to the grain consisted of different weights (50, 100, 150, and 200 g) and heights (7, 17 and 23 cm), applied on two kernel regions, dorsal and ventral surface; the grain was then submitted to the iodine and damage severity tests. A completely randomized experimental design was adopted, in a 7 x 3 x 2 factorial scheme represented by seven hybrids, three weights and two regions: four subsamples of 25 grains were used in each treatment. The results allowed the hybrids to be separated into three levels of resistance: susceptible (AS1535, AS1570, and AS1575), intermediately resistant (AG7000 and P30F80), and resistant to mechanical damage (AS3430 and DKB390). The region most susceptible to the impacts was the ventral surface, where embryo is located. The proposed method was effective to produce differential mechanical damage indices between susceptibility and resistance standards.
mechanical damage; grain quality; iodine test
