Effects of apical meristem loss on sylleptic branching and growth of hybrid poplar

• Published in: Biomass & bioenergy Vol. 31; no. 7; pp. 453 - 459
• Main Author: Zeleznik, Joseph D.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.07.2007; Elsevier
• Subjects: Applied sciences; Biomass; Energy; Exact sciences and technology; Natural energy; Populus; Short-rotation-intensive culture; Syllepsis; United States; North America; America; Syllepsis; Populus; Biomass; Short-rotation-intensive culture; Short rotation coppice; Plant growth; Hybrid; Meristem; Poplars
• ISSN: 0961-9534; 1873-2909
• DOI: 10.1016/j.biombioe.2007.01.024

The effects of apical meristem loss on the growth and development of hybrid poplar trees was investigated. This was done by clipping back either the apical meristem alone (dividing cells), or the apical meristem plus a small amount of additional stem tissue (expanding cells, <1 cm), at various times during the first growing season. Two clones (NM6–nonsylleptic habit, and DN34–slightly sylleptic habit) were tested at close spacing (0.6 m) in the nursery. Clipping generally increased the number of sylleptic branches formed. Clipping 69 days after planting resulted in the largest number of sylleptic branches while clipping 4 weeks later gave no increase in syllepsis. Clipping temporarily reduced height growth of both clones but total height at the end of the first growing season was not affected by any treatment. There were some slight differences in growth during the second growing season; despite these differences, total stem biomass and total tree biomass after 2 years were not affected by temporary loss of the apical meristem in the first growing season. Results suggest that death or removal of hybrid poplar apical meristems by tip borers or ungulates has no long-term effects on aboveground growth as measured by height or biomass.