A comparison between two- and six-row winter barley genotypes for above-ground dry matter production and distribution

Abstract

A comparison between 2- and 6-row winter barley genetoypes was carried out in 1989 and 1990 at the plant breeding station of Estrées-Mons (Somme, France). The above-ground dry matter (DM) and nitrogen (N) production and distribution were studied at anthesis and at harvest in 22 genotypes in 1989 (11 2-row and 11 6-row) and 31 genotypes in 1990 (15 2-row and 16 6-row) representing the most widely grown winter barley cultivars in France. The average grain yields were high (751 and 839 g.m-2 in 1989 and 1990) thus allowing a comparison of the genotypes at a high level of production. In both years, the 6-row outyielded the 2-row by about 7%. This difference results from their superior DM production (+2.5% on average) and harvest index (49.3 vs 47.4). The 6-row have a higher DM production due to their larger ear dry matter from anthesis onwards. Neither the duration of the sowing-anthesis period nor the leaf area index can explain this difference. Post-anthesis assimilation is quite similar for the 2 types. The 6-row have a better harvest index despite their greater height and the existence of a negative correlation between height and harvest index within each group. Grain N yields are similar. The higher grain yield of 6-row genotypes compensates for their lower grain N concentration. © 1992.