RT Journal Article SR Electronic T1 Uptake and Distribution of Trunk Injections in Conifers JF Arboriculture & Urban Forestry (AUF) JO JOA FD International Society of Arboriculture SP 73 OP 79 DO 10.48044/jauf.2004.009 VO 30 IS 2 A1 M.A. Sánchez-Zamora A1 R. Fernández-Escobar YR 2004 UL http://auf.isa-arbor.com/content/30/2/73.abstract AB Seven coniferous species, four of them resinous, were injected with pressurized latex capsules containing 250 mL (7.5 oz) of water using different injector sizes ranging from 3 to 7 mm (0.12 to 0.28 in.) in diameter and from 25 to 70 mm (1 to 2.8 in.) in length. In resinous species, uptake was slow and sometimes incomplete, particularly in spring when resin secretion was high. Water uptake rate decreased when the smaller-diameter injectors were used. An injector with a diameter of 7 mm and length of 70 mm had the fastest rates of water uptake. In nonresinous species, the injector with a diameter of 4 mm (0.16 in.) worked as well as the more widely used 6 mm (0.24 in.) injector in most cases, with the added advantage of reducing wound size and decreasing healing time. Spanish fir (Abies pinsapo) trees were injected with a 50 mM solution of rubidium chloride. Rubidium (Rb+) was recovered in all tree sections sampled for both healthy and unhealthy trees. Healthy trees had a greater and faster uptake rate than unhealthy ones. Results indicate that conifers were injected efficiently. Uptake rate is slower than in angiosperms, but distribution is more uniform. Due to this slowness, the low-pressure trunk injection methods composed of individual devices on each injection point are more efficient for injecting coniferous trees.