Analysis of yield of winter wheat grown at increasing levels of potassium

Winter wheat was grown in pots receiving 0 ( K 0 ), 60 ( K 1 ) and 120 ( K 2 ) mg K 100 g −1 soil to investigate the effect of potassium (K) supply on the following yield components: number of ears, number of grains per ear and single grain weight. Mature grain yield increased from 34.5 g per pot at K 0 to 81 g at K 1 and 89.9 g per pot at K 2 . Straw yield increased from 35.4 ( K 0 ) to 123.2 g per pot ( K 2 ), reflecting an increase in leaf area and photosynthesis. K fertiliser lengthened the period of grain filling by 3‐4 weeks both by advancing anthesis and delaying senescence. The longer grain filling period fed by more abundant assimilates resulted in single grain weights of about 40 mg in central and lower spikelets and as much as 30 mg in the apical spikelets.