Abstract:
Seeds of silver grass and cape-weed contained so little potassium that the roots of these species could only penetrate a highly potassium-deficient sand to a depth of 3 or 4 cm. By contrast, lupin seeds contained enough potassium to allow root development to a depth of at least 90 cm. The behaviour of other species studied was intermediate between these extremes. With seeds low in total potassium, evidence was obtained of a beneficial effect of applied potassium on seedling emergence. A study of seeds varying in total potassium from 1