YIELDING ABILITY AND YIELD STABILITY OF LINSEED IN CENTRAL-EUROPE

Successful linseed (Linum usitatissimum L.) cropping in Central Europe depends on yielding ability and yield stability of cultivars, as well as on reliability of production systems. During 1991 and 1992, two experiments spread over 14 representative locations in Germany and one location in Switzerland were conducted to analyze the effects of cultivar, N fertilization, and seeding rate on yield and, especially, on yield stability. Experiment 1 tested the effects of seeding rate (200, 400, 600 and 800 seeds m(-2)) and N fertilization rate (60 and 100 kg N ha(-1)) at nine locations. Experiment 2 investigated yield performance and yield stability of 16 cultivars and lines at nine locations. At 60 kg N ha(-1), 200 and 800 seeds m(-2) resulted in the lowest yields. Additionally, 200 seeds m(-2) was associated with significant yield instability, At 100 kg N ha(-1), seed yields reached a plateau at seeding rates of 400 and 600 seeds m(-2). At 800 seeds m(-2), yield decreased significantly. Only the 400 seeds m(-2) rate resulted in significant yield stability. Two cultivars (Atalante, McGregor) and two lines (DSV-5, DSV-6) were superior in yield to other genotypes, but only Atalante and DSV-6 were both high yielding and stable in yield. Adjusting seeding rate in relation to soil-available N is a useful tool to optimize linseed production in a given location. It is concluded that high-yielding cultivars are available that respond adequately to production potential at each of the selected locations.