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

Abstract

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