Promotion of Flowering in Young Larix laricina Grafts by gibberellin A4/7 and Root Pruning

1990

S. 1448-1452

1 Abb., 3 Tab., 14 Lit. Ang.

Unselbständiges Werk

200088976

Flowering was promoted on potted, indoor, and field-grown 3-year-old juvenile and mature Larix laricina (Du Roi) K. Koch grafts by foliar sprays of the plant-growth regulator gibberellin A4/7 and root pruning Biweekly gibberellin A4/7 applications of three different durations, commencing at the start of long-shoot elongation, yielded similar increases in female flowering in the greenhouse; this effect was synergistically enhanced by root pruning. Male flowering was promoted by gibberellin A4/7 + root pruning in mature but not juvenile grafts. In the field, female flowering was also promoted by the gibberellin A4/7 treatment commencing at the start of shoot extension, but gibberellin A4/7 applications starting later were not effective. Grafted scions from mature trees responded significantly better to gibberellin A4/7 + root pruning than did seedling scions.