CROP AND HARVESTING OPERATION CHARACTERISTICS AFFECTING FIELD LOSSES AND PHYSICAL QUALITIES OF SOYBEANS – PART I

Abstract

This study evaluated the effects of soybean moisture content, stink bug and weathering damage, and combineground speed, age, and threshing cylinder rotational speed on seed breakage/splitting, seed coat damage, material other thangrain content (MOG), and field losses. There were significantly more broken/split seeds at moisture contents below 12% andsignificantly less seed coat damage above 14%. There were positive linear correlations between moisture content andweathering damage, threshing cylinder rotation speed, and MOG; a negative linear correlation between moisture contentand broken/split seeds; and a non-linear (quadratic) correlation between moisture content and field losses. Stink bug damageup to 6% resulted in significantly less broken/split seeds, seed coat damage, and MOG. Stink bug damage correlated linearlyand positively with each of the three response variables. Weathering damage up to 6% resulted in significantly lessbroken/split seeds and seed coat damage. Weathering damage also correlated linearly and positively with broken/split seeds,seed coat damage, and MOG. Combine ground speeds above 5.5 km/h resulted in significantly more seed coat damage andless MOG. Ground speed correlated linearly and positively with seed coat damage, linearly and negatively with MOG content,and non-linearly (quadratic) with field losses. There were no significant differences between the two levels of combine agefor any of the response variables. However, there was significant linear correlation between combine age and field lossesshowing trends for obtaining lower field losses with newer combines. Threshing cylinder rotational speeds up to 600 rpmresulted in significantly less broken/split seeds, seed coat damage, and MOG. Threshing cylinder rotational speed alsocorrelated linearly and positively with all three response variables.