Potassium uptake efficiency of young plants of three potato cultivars as related to root and shoot parameters

Three potato cultivars, Kufri Badshah, Kufri Chandramukhi, and Kufri Jyoti were grown in low potassium (K) soil with and without K in a pot experiment to test their K uptake efficiency. Two harvests were taken to obtain final dry matter accumulation (DMA) rates of shoot and root growth and K uptake per unit root (K-influx). Relative DMA without K (expressed as percent of DMA with K) was 66, 75, and 90% for Kufri Badshah, Kufri Jyoti, and Kufri Chandramukhi, respectively, showing that Kufri Chandramukhi had a higher K uptake efficiency than other cultivars. High K uptake efficiency of Kufri Chandramukhi was due to its high K-influx while low K uptake efficiency of Kufri Badshah and Kufri Jyoti was due to low K-influx which nullified the effect of their high root-shoot (DMA) ratio. The potassium efficient cultivar, Kufri Chandramukhi, utilized more K from non-exchangeable soil source (46%) than Kufri Jyoti (25%) or Kufri Badshah (17%).