Differences in competitive ability and coope-rating effect among the lines of sugar beets, Beta vulgaris L.

Abstract

In order to study the effects of competition and cooperation among individuals carring the different genotypes, eight lines of sugar beets were grown in pure stands and incomplete diallel combination of mixtures of between-row. Row component data were collected from center rows grown between the same or different lines. Competitive abilities and cooperating effects of lines were defined in following ways : Competitive ability= (M-P) + (P'-M'), Cooperating effect= (M-P) - (P'-M'), where M and P stand for the mean performances of the line at mixture and at pure stand. respectively, and M' and P' the mean performances of the associate at mixture and at pure stand, respectively. There were statistically signiflcant differences in competitive ability and cooperating effect among the lines. And no relationship was observed each other on performance at pure stand, competitive ability and cooperating effect. These results in sugar beets suggest that competitive ability and cooperating effect would be under the genetic controls and be independent from the plant type and/or growth vigour. respectively, and M' and P' the mean performances of the associate at mixture and at pure stand, respectively. There were statistically signiflcant differences in competitive ability and cooperating effect among the lines. And no relationship was observed each other on performance at pure stand, competitive ability and cooperating effect. These results in sugar beets suggest that competitive ability and cooperating effect would be under the genetic controls and be independent from the plant type and/or growth vigour.