SOME STUDIES ON ROOTING IN CASHEW (ANACARDIUM OCCIDENTALE LINN.) AIR LAYERS

ashew can be propagated by air layers but the extent of survival of the air layered plants in the field is limited (40 to 66 percent), probably because of the small number and brittle nature of the adventitious roots formed during propagation. Studies at U.W.I., St. Augustine, have shown that root initation in cashew air layers occurs in the callus which is formed at the wound and increasing the amount of callus increases the total number and length of roots formed. Callus, and consequently root formation, were increased by using two consecutive rings in the marcot, joined by a bridge of bark. However, when three rings were used callus formation, as well as root initiation and elongation, were reduced. Applying auxins, particularly IBA at 300 p.p.m. to the air layers increased root elongation but had no significant effect on root initiation