Search

Rutin and pyrogallol applied, using the quick-dip method, in concentrations 500- 1500 mg/liter promoted rooting markedly, provided auxin was given simultaneously. The fungicide Captan used as an admixture to auxin promoted rooting only occasionally. SADH used separately was inactive.

The cuttings taken at flowering time or earlier rooted much better than those taken after flowering. The apical cuttings rooted more aboundantly than those taken from medium or basal part of the shoots. Different auxins: NAA, IAA IBA and 2,4-D in optimal concentrations differed very little in their stimulatory effect or rooting. Several substances: indole, tannin, pyrogallol, thiamine, ascorbic acid, pyridoxine, ryboflavine, niacine, retardant SADH, abscisic acid, and boric acid promoted rooting of cuttings when used separately. Their combined effect with auxin was in most cases additive but sometimes synergistic. Three phases of rooting process were discerned.

Pyrogallol and salicylic acid used alone or in combination with auxin increased markedly the number of rooted cuttings, the number of roots per cutting and the total length of roots per cutting. The effect of phenolic substances was most visible when treatment was done in late summer, i.e. when natural ability to form roots was very low.