Single-kernel mass determination for grain inspection using machine vision

The effects of moisture content (m.c.) on artificially wetted grain mass were quantified for wheat (Canada Western Red Spring (CWRS) and durum), barley oats, and rye at moisture content between 10 and 22% (wet basis, w.b.) and for canola at moisture content between 5 to 15.5% (w.b.). The grain mass increased linearly with an increase in grain moisture content. To determine the effect of growing regions on the grain mass, experiments were conducted at two fixed moisture contents (13.5 +/- 0.5% and 16.5 +/- 0.5% w.b.) for CWRS wheat collected from 20 different regions in Western Canada. The variations in grain mass due to growing region were much larger than due to change in moisture content. Relationships between grain mass and other grain features extracted from images acquired for both dorsal (crease-down) and ventral (crease-up) positions were determined. Out of 13 features analyzed grain image-area showed the best correlation with grain mass (correlation coefficient = 0.91). The grain placement (dorsal or ventral view) did not significantly affect the above mentioned correlation.