The growth of watercress (Rorippa nasturtium aquaticum (L) Hayek) from seed as affected by the phosphorus nutrition of the parent plant

Abstract

Seed was collected from watercress plants grown in sand cultures supplied with nutrient solutions containing either 0.2, 1.0, or 4.0 me/l of phosphorus. The seed, called P1, P2, and P3 seed respectively, contained 0.47, 0.84, and 0.95 per cent P, while other differences in its composition and in its size were relatively slight. When grown under conditions of phosphorus deficiency, 7- to 9-week-old plants from P3 seed were larger than those from P2, which in turn were larger than those from P1 seed, but such differences were not measurable when the plants were mature at 16 to 20 weeks. When grown in cultures adequately supplied with phosphorus there were no differences between the weights of plant from any of the three kinds of seed either at 6 to 7 weeks or at 16 to 20 weeks. The different levels of phosphorus supply in the first generation had no measurable effects on 6 1/2-week-old plants in the third generation.