TY - JA AU - Banziger,M. AU - Feil,B. AU - Stamp,P. TI - Competition between nitrogen accumulation and grain growth for carbohydrates during grain filling of wheat SN - 1435-0653 PY - 1994/// KW - Carbohydrate content KW - Carbohydrate metabolism KW - Nitrogen metabolism KW - Nitrogen retention KW - Plant developmental stages KW - Seeds KW - Triticum aestivum KW - AGROVOC KW - Wheat N1 - Peer-review: Yes - Open Access: Yes|http://science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=MASTER&ISSN=0011-183X N2 - A study was conducted to determine whether increased N accumulation during grain filling of wheat may reduce carbohydrate availability for grain formation. In a field experiment on a sandy loam soil at ETH Zurich, Switzerland in 1990-91, 4 spring wheat genotypes, grown under 3 early N regimes (soil + fertilizer N rates of 40, 90 or 140 kg/ha), were supplied with 0, 50 or 100 kg N/ha at heading. The effects of late N application on photosynthesis rate (only in 1991), water soluble carbohydrates (WSC), grain growth and yield were recorded. N application at heading reduced WSC content of the shoot at anthesis by 8.5 g WSC per gram of accumulated N. During grain filling, a steady regeneration of WSC reserves in the stem occurred, though N accumulation was still enhanced by late application of N. By 320 degree days after anthesis, differences in stem WSC reserves between late N levels had disappeared. Measurements of photosynthesis rate and leaf area duration indicated that photosynthetic capacity of the canopy was increased by application of late N. Apart from the detrimental effect of late tillers which were induced by late N application, late N application generally resulted in higher grain yields. Since N compounds can be invested in light interception (photosynthesis rate, leaf area duration) before they are translocated to the grains, the consumption of energy and carbon skeletons for assimilating N cannot be considered alone as reducing carbohydrate availability for grain formation T2 - Crop Science ER -