A New Device for Hot-callusing Graft Unions1

There are various problems associated with hot-callusing graft unions of dormant fruit and nut trees. Since the whole plant is exposed to elevated temperatures, growth is promoted not only at the graft union, but also from the scion buds and the roots. Translocation demands are placed on the graft union once growth of scion buds starts and leafing out occurs. Scion buds and leaves will desiccate if a callus bridge between rootstocks and scion is inadequately formed (1).