AN ELECTRICAL-CONDUCTIVITY METHOD SUITABLE FOR QUANTITATIVE MECHANICAL DAMAGE EVALUATION

This investigation deals with the suitability of a method based on ele ctrical conductivity measurements, to evaluate mechanical damage in so ybeans. Two modifications on the electrical conductivity test methodol ogy, used on seed quality evaluation, were made: the utilization of a new number of grains per volume of water; and the introduction of a st irring process. Samples of soybeans, cultivars IAC 8 and Cristalina, w ere damaged by cutting the grain at the cotyledone junction and by imp act of a mass falling from different heights. Samples of varying level s of damage were soaked in distilled water and their electrical conduc tivities were measured during 160 min at time intervals of 20 min. The results showed that at soaking times other than zero, the response of electrical conductivity due to variations in percent of damage was li near for IAC 8 and quadratic for Cristalina. This technique was consid ered suitable for the intervals of the variables and for the condition s used in this study. The introduction of stirring process reduced det ection of low level damage of samples to 20 min.