Silicon uptake by wheat and its relation to grain yield and water use

Abstract

The Si content in wheat in S Australia was measured in 46 experiments over 4 seasons. The percentage Si, Si uptake and its distribution in the plant tops varied greatly. The maximum uptake was 2.4% of the dry matter production, but high yields were obtained with a lesser percentage than this. Of the total Si uptake, 16-48% was found in the glumes. The correlations between grain yield and Si, either in the glumes or in the plant, were generally poor. There were significant relationships between water use and Si. The relationship with Si uptake in the tops was best and accounted for 77% of the variation in water use, but Si analyses were not a satisfactory measure of water use efficiency. The effect of agronomic practices on the relationships is discussed.