Lichtaufnahme und Stoffproduktion eines konventionellen und eines epigonalen Genotyps der Weißen Lupine (Lupinus albus)

Light interception and dry matter production of a conventional and an epigonal genotype of the white lupine ( Lupinus albus )
Yield formation of two white lupin ( Lupinus albus ) genotypes differing substantially in growth habit was investigated. Grain production was quantified as the product of harvest index and dry matter production, the latter being a function of light interception and utilization. Experimental data were obtained from two-year field experiments with a combined variation of plant density and distribution. The conventional, freely branching cultivar Kalina showed higher leaf area indices and growth rates than the "epigonal" (little branching) genotype. The higher growth rates of Kalina were partly due to increased light interception, but were mainly a result of a higher light use efficiency. This can be explained with a more even light distribution over a greater leaf area. The more rapid increase of the harvest index in the epigonal genotype compared to Kalina only partially compensated for the differences in dry matter production.