Publication Date:
1981-09-01
Description:
Annual changes in the radial and longitudinal extent of grooves above and below branches on the stem of a 40-year-old red pine (Pinusresinosa Ait.) were determined by examination and measurement of annual rings on cross sections. Grooves appeared above branches when they were in the fourth whorl and maximum vertical extent occurred about the time of branch death. Ring widths within grooves compared with those between grooves decreased slowly at first, then more rapidly, reached a minimum the year after branch death, and then increased. Below branches, groove initiation was later, far less extensive, and minimal within-groove compared with between-groove ring widths occurred the year of branch death. The course of groove development appeared to be associated with the changing vigor of branches and with the nature of the junction between stem and branch. It is suggested that groove development above branches in red pine is the result of localized water deficiency, whereas groove development below branches is related to reduction in photosynthate availability.
Print ISSN:
0045-5067
Electronic ISSN:
1208-6037
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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