SCIENCE, December 8, 1933, Vol. 78, No. 2032, page 532.

PROPAGATION OF HYBRID AMARYLLIS (HIPPEASTRUM) BY CUTTAGE
HAMILTON P. TRAUB
ORLANDO, FLA.

SOME experimental results concerning cuttage in relation to the physiology of reproduction in the Amarylleae Genuinae and Pancratiae are worthy of brief mention, since the subject has apparently received little attention.

1H. Nehrling, ''Die Amaryllis oder Rittersterne (Hippeastrum).'' Paul Parey, Berlin, 1909.

The Nehrling‑Mead strain of Hybrid Amaryllis (Hippeastrum) was used in the initial experiments. In the breeding of this strain, H. reginae, H. equestre, H. aulicum, H. psittacinum, H. pardinum, H. solandriflorum, H. leopoldi and possibly also H. reticulatum were apparently utilized.¹ Blooming size bulbs were cut (1) lengthwise into quarters as far as the middle of the root base, and (2) into quarters. A variation was introduced in each of the two types, consisting of cutting off a little less than half of the top of the bulb before making the lengthwise cuts.

The two "callusing‑sprouting" media used were sand and loam. The partially quartered bulbs and the quarters were planted in these media contained in clay pots. Moderate water was applied until growth had definitely started. Any flower buds already formed in the fractions expanded and flowered, and leaf growth appeared above the surface in some eases in less than 30 days. In three months the original ten bulbs had given rise to 15 new bulbs, an increase of 50 per cent. In another month the number of new bulbs had increased to 43, an increase of 330 per cent.

On inspection it was noticed that new bulbs had been formed at the leaf axes. The roots, however, issued from the root base fraction of the mother bulb. Roots were more abundant and longer in case of partial quartering. Complete severing apparently retards root formation. The partially quartered bulbs had entirely or practically broken into quarters by the pressure of the developing new bulbs. Where still slight connections were present, these were broken at transplanting time. The sand "callusing‑sprouting" medium gave disease‑free plants, as contrasted with some red rust on plants propagated in loam.

The work is being extended to include a study of the maximum number of new bulbs obtainable from one bulb, the time required for new bulbs to reach blooming size, the best season to carry out the operation and also the application of this principle to the propagation of other types of Amarylleae such as Crinum, Hymenocallis, Vallota, Lycoris, etc. A more detailed report will appear in the 1934 Year‑book of the American Amaryllis Society.