Importance of cutting diameter and method of production on early growth of hybrid poplar

Rapid early growth of hybrid poplars--Populus spp. -established from hardwood cuttings is critical to the success of plantations. Without rapid growth, weed competition and drought can significantly affect tree survival and productivity. Producing vigorous cuttings, quickly developing roots, and initiating shoot growth are therefore important. Hardwood cutting diameter was not an indicator of tree vigor for 8 of 15 hybrid poplar clones tested and only a weak indicator for 7 clones. The angle at which cuttings are excised from stems significantly influenced early growth of 1 poplar clone. The assumption that cutting diameter is an important index of subsequent growth is challenged, and the lack of criteria for excising cuttings is addressed