文摘
Durum wheat cropping in semi-arid areas of West Asia and North Africa is frequently integrated into a cereal–livestock farming system. The wheat straw, mostly used for feeding animals, represents an important commodity, its average sale price per unit weight being not less than 40 % of that of grain in three recently surveyed areas. There is uncertainty whether the widespread, short-statured wheat plant type could be economically preferable in these environments relative to a tall type, especially when considering straw yield. Within the Mediterranean durum wheat gene pool, mediterraneum typicum germplasm possesses a markedly tall stature, implying high straw yield. In a first phase of evaluation under prevailing conditions of northern Syria, 13 entries characterized by early heading and good agronomic performance were identified from a collection of about 2000 Tunisian and Algerian accessions. In a second phase reported here, these entries were evaluated in relation to two widely grown adapted cultivars, i.e., the semi-dwarf variety Cham 1 and the local landrace Haurani, across four environments of northern Syria diversified for rainfall and soil characteristics. In an economic assessment, the straw value was expressed in terms of grain-equivalent, defining an economic yield as: grain yield+(0.40×strawyield). Compared with the control cultivars, the mediterraneum typicum entries were taller but tended to later heading with a similar grain filling duration. However, a few entries as early as the controls were also found. Almost all exotic entries outperformed Haurani for economic yield. Two entries showed significantly higher (P<0.05) economic yield (>12 % ) and aerial biomass across environments than Cham 1, owing to higher straw yield and similar grain yield. They compensated for the relatively lower spike fertility by heavier kernels. Genotype×environment interactions were generally limited for yield-related traits. Straw yield was closely associated with plant height (r=0.76, P<0.001) but not with number of fertile tillers. No trade-off between grain and straw yields was apparent. The results support the interest of a tall durum wheat plant type derived from the mediterraneum typicum gene pool for enhancing the profitability as well as the sustainability of semi-arid Mediterranean farming systems.