Dry matter accumulation and distribution in winter wheat grown in a humid continental climate

Abstract

The growth of a crop of 'Arrow' winter wheat (Triticum aestivum L. em Thell.) was studied in detail from 2 weeks before ear emergence to maturity. Aboveground dry weight increased up to 4 weeks after ear emergence, when it reached a maximum value of 1.4 kg∙m−2, and then decreased marginally. The rate of aboveground dry matter accumulation over a 6-week period beginning 2 weeks before ear emergence averaged 24.4 g∙m−2∙day−1.Rapid ear growth commenced some 2 weeks after ear emergence and continued until after the crop had lost all green coloration. Dry matter accumulation in the ears in the period beginning 3 weeks past ear emergence was greater than accumulation in the aboveground parts of the crop as a whole. This indicated that much of the ear dry matter increase in the latter part of the grain filling period occurred as a result of translocation of previously accumulated assimilates. The stem fraction (including leaf sheaths), the major aboveground reservoir of material that is translocated to the ear, decreased from 800 g∙m−2 at 3 weeks after ear emergence to 493 g∙m−2 at maturity.