Title : Producing Fiber Flax Using Modern Machinery and Field Retting

approv Steven J. Knapp Fiber flax (Linum usitatissimum L.) production in the Willamette Valley ended in Oregon around 1957 before newly developed technology and fiber cultivars were available. The purpose of this research was to explore the use of modern methods and new cultivars. Field studies were conducted to evaluate cultivars and optimum cultural practices that would produce the highest yield and best fiber quality in the Willamette Valley on Woodburn silty clay loam. A study was conducted to assess the winter hardiness of fifty flax cultivars. The effect of four different pull dates on straw and fiber yield and fiber quality were investigated at two sites in 1995 and 1996. Pulling in stage 2, 3, or 4 resulted in an increase in straw yield over pulling in stage 1 in 1996. No differences were detected in fiber yield or caustic weight loss in response to pull date in either year. An acceptable pulling window is stages 1-3 (range of 900 to 1300 growing degree days). Retting took Redacted for Privacy 13 weeks in both years. Rainfall during the retting period was 10.7 cm in 1995 and 6.9 cm in 1996. A field study was conducted in 1995 and 1996 to test the effect of three nitrogen (N) levels (50, 75, and 100 kg ha') and three fiber flax cultivars (Ariane, Cascade, and Viking) on straw yield. There was a significant increase in yield with increased N levels in 1996. Higher levels of N increased yield in all three cultivars in both years. Lodging of 'Cascade' increased with increased N levels in 1995. The effect of three planting dates on yield and stand density of Ariane fiber flax were investigated in 1995. The 31 March planting date produced the most retted straw (9704