The Importance of Ash Elements in the Cultivation of Excised Root Tips

Abstract
The beneficial effects on the growth of excised root tips of the addition of agar or qualitative filter paper to a mineral nutrient soln. containing sugar are ascribed to the ash elements contained in those substances rather than their organic constituents or physical character. Additions of filter paper ash or of agar ash proved beneficial. ZnCl2, MnCl2 and Na borate at the concns. used were not as beneficial as the agar or filter paper.