Correlation and Path Coefficient Analysis for Some New Released (00) Spring Rapeseed Cultivars Grown under Different Competitive Systems

The inter-relationships between fifteen quantitative characters of spring oilseed rape were computed using four "free erucic acid" cultivars viz. Callypso, Semit 2080, Semu DNK 203/84 and Semu 304 , grown under two different distances between drill rows (16 and 32 cm) and three population densities (30, 60 and 90 plants/m²). The experiments were carried out in Kiel, West Germany, in 1986 and 1987 seasons.
Positive and highly significant values were obtained in the two seasons between seed yield per plant and the characters: dry matter (DM) per plant, per main stem and per branches, number of branches, siliqua per plant or per branches and yield per branches. All the characters that showed strong association with yield/plant behaved in a similar way and similar magnitudes with yield/branches. By contrast, yield/main stem showed different magnitudes in the two years with the previous characters and the association was weak or absent in most cases.
Seed index and the quality traits (oil and protein %) did not correlate significantly with the majority of the characters studied. Only the association between DM/main stem and protein content showed highly significant negative values in both seasons.
Path coefficient analysis revealed that number of siliqua per plant had the highest direct effect on seed yield/plant in both years. The source character (DM) affected yield/plant indirectly through number of siliqua per plant and the indirect contribution was high m both years.