EFFECT OF WEATHERING ON FALLING NUMBERS OF STANDING AND WINDROWED WHEAT

Abstract

Weathering damage, as reflected by falling number changes in standing and windrowed red and white wheats, was compared in 14 cultivars grown in small plot trials and in four cultivars grown in field-scale trials. Weathering damage caused a broad range of falling number changes within both the red and white seed coat color classes of cultivars. Mean falling number for the weathering resistant white seed coat class exceeded that of the weathering susceptible red seed coat class in both years, indicating a range of genotypic expression of weathering resistance within both red and white wheats. Falling number was markedly lower in windrowed than in standing wheat following weathering, particularly in the weathering susceptible cultivars. These differences were readily apparent with total rainfall as low as 47 mm during the weathering period. The greater weathering susceptibility of the windrowed than of the standing wheat was attributed to higher moisture contents and slower drying following rains in windrowed compared to standing crops. Test weight was unaffected by harvest treatment. Commercial grades were higher for weathered samples of standing than of windrowed Neepawa wheat at one location.Key words: Triticum aestivum L., falling number, volume weight, red and white seed coat