EFFECT OF TIME OF SWATHING AND DESICCATION ON PLANT DRYING, SEED COLOR AND GERMINATION OF FLAX

In field studies conducted between 1988 and 1990, flax (Linum usitatis simum L.) was swathed or desiccated with diquat, glufosinate-ammonium or glyphosate at various times between the 0 and 100% brown capsule st ages to determine the effects on drying of plant components, seed disc oloration and germination. Leaf and capsule browning were complete abo ut 1 wk after application of diquat and glufosinate-ammonium and about 2 wk after application of glyphosate. Stem browning was variable from one application to another, but was usually adequate for harvesting 1 -2 wk after application of diquat and glufosinate-ammonium and 3 to 4 wks after application of glyphosate. Diquat gave the most rapid stem b rowning and glyphosate the slowest. In most cases, swathing and applic ation of diquat or glufosinate-ammonium resulted in capsule moisture l ow enough for harvest 2 wks after treatment. Drying of capsules follow ing glyphosate application was less rapid. Early applications of glufo sinate-ammonium sometimes resulted in darker brown seed. Glyphosate ap plied before all capsules were mature reduced seed germination.