The Relation between the Putrescine Content and Potassium Status of Black Currant Leaves

Abstract

Black currant cuttings were grown with six levels of potassium and two levels of phosphorus. Shoot length, leaf number, leaf weight, and deficiency symptoms were recorded 11 and 16 weeks after commencement of the treatments, and leaf samples were analysed for putrescine, potassium, and nitrogen. Shoot length, leaf number and leaf weight were reduced by potassium deficiency, the greatest effect being observed in leaf weight Potassium-deficiency symptoms appeared first on the lower branches, the most severe deficiency symptoms being found on the plants grown with high phosphate. In terms of the fresh weights, the highest concentration of both putrescine and potassium were found in the leaves of the upper shoots. Lower putrescine and higher potassium levels in the leaves were found in the low-phosphate nutrient series. In terms of cation equivalents the deficit of potassium was compensated to the extent of 30 per cent by the formation of putrescine.