Abstract
This study addresses whether a freely tillering wheat cultivar with greater vegetative sink strength (cv. "Silverstar") can benefit more from increasing atmospheric CO2 concentration [CO2] than a restricted tillering cultivar with greater reproductive sink strength (cv. H45) in a water-limited cropping system. Growth, yield, yield components and nitrogen at three developmental stages (stem elongation, anthesis, maturity) and water soluble carbohydrates (WSC, anthesis) were evaluated at two CO2 concentrations (ambient [CO2], ~395ppm, elevated e[CO2], ~550ppm) across six environments using the Australian Grains Free Air CO2 Enrichment (AGFACE) facility. Cv. "Silverstar" had more tillers than cv. "H45" throughout development; whereas, cv. "H45" had greater WSC storage and more and heavier kernels per spike. CO2 enrichment stimulated grain yield in both cultivars similarly, but this stimulation was caused differently: For cv. "Silverstar", grain yield increase was exclusively linked to an increased number of fertile tillers; whereas, in cv. "H45", yield stimulation was additionally associated with increased kernel weight and kernel numbers per spike. We conclude that in a Mediterranean-type, water-limited environment high tillering capacity alone does not ensure greater benefits from CO2 fertilization but that both pre and post-anthesis source-sink relationships play a significant role in this environment as well.
Original language | English |
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Pages (from-to) | 21-28 |
Number of pages | 8 |
Journal | European Journal of Agronomy |
Volume | 64 |
Early online date | 24 Dec 2014 |
DOIs | |
Publication status | Published - 1 Mar 2015 |
Keywords
- Free air carbon dioxide enrichment (FACE)
- Growth
- Low rainfall
- Source-sink relations
- Triticum aestivum L.
- Yield
ASJC Scopus subject areas
- Agronomy and Crop Science
- Plant Science
- Soil Science