Aspects of nutritional physiology in watercress: 'Rorippa nasturtium-aquaticum' (L.) Hayek

Abstract

The roles of adventitious and basal roots were studied experimentally during investigations into the nutritional physiology of watercress. Absorption and translocation experiments with ³²P, ⁸⁶Rb and ⁵⁹Fe showed adventitious roots absorb the major proportion of ions, basal roots a smaller proportion with little direct foliar uptake of nutrients. Field trials demonstrated basal roots could absorb supplementary nutrients from the bed substrate, improving crop uniformity and production.

Watercress cultured in bed simulation tanks at different levels of nitrogen, phosphorus and potassium, responded with increased yields to levels of phosphorus and potassium higher than normally occurs in natural water supplies. Yields in the higher nitrogen solutions were similar to those obtained from natural irrigating waters.