An automatic system for measuring shoot length in Sitka spruce and other plant species.
Abstract
The device, which does not require attachment to the shoot apex, includes a light transmitter/receiver system that can be continually repositioned over a range of 250 mm so that the light beam is just clear of the shoot tip. The device has a resolution of plus or minus 0.1 mm at constant temp., and plus or minus 0.2 mm over the range 10-40 deg C. It was successfully used in the field to measure diurnal variations in the growth rate of the leading shoot of a 13-yr-old Picea sitchensis.