Skip to Main Content
Seasonal branch and fine root growth of juvenile loblolly pine five growing seasons after fertilizationAuthor(s): M.A. Sword; D.A. Gravatt; P.L. Faulkner; J.L. Chambers
Source: Tree Physiology. 16: 899-904
Publication Series: Scientific Journal (JRNL)
Station: Southern Research Station
PDF: Download Publication (0 B)
DescriptionIn 1989, we established two replications of two fertilization treatments in a 10-year-old loblolly pine (Pinus taeda L.) plantation. Between March and September 1993, branch internode and needle fascicle expansion in the upper and lower third of crowns were measured weekly on three south-facing branches of each of four trees, and new root initiation and elongation were measured at 10-day intervals in three vertical rhizotrons per plot. In one replication, soil water content was measured daily. Fertilization significantly increased the expansion of first flush internodes in the upper crown and first flush needle fascicles in the upper and lower crown. New root growth was stimulated by fertilization in the second half of the growing season. The timing of root growth responses to fertilization corresponded to branch phenologies in the upper and lower crown that were conducive to increased basipetal transport of photosynthate. We conclude, therefore, that new root growth was linked to source--sink activities in the crown. Root initiation was greater in the upper than in the lower part of the soil profile; however, as the growing season progressed and water deficit increased, this relationship was reversed. The effect of soil depth on seasonal root growth was closely associated with water availability, suggesting that root initiation deep in the soil profile is critical for the continued production of new roots in environments subjected to short-term, but relatively severe, water deficits.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationSword, M.A.; Gravatt, D.A.; Faulkner, P.L.; Chambers, J.L. 1996. Seasonal branch and fine root growth of juvenile loblolly pine five growing seasons after fertilization. Tree Physiology. 16: 899-904. 6 p.
Keywordsbranch phenology, rhizotrons, source--sink relations, water deficit.
- Seasonal Shoot and Needle Growth of Loblolly Pine Responds to Thinning, Fertilization, and Crown Position
- Branch growth and gas exchange in 13-year-old loblolly pine (Pinus taeda) trees in response to elevated carbon dioxide concentration and fertilization
- Reapplication of Silvicultural Treatments Impacts Phenology and Photosynthetic Gas Exchange of Loblolly Pine
XML: View XML