BUCK, MEGHAN*, ROBERT REINSVOLD, GERRY SAUNDERS, and TERESA HINZ. University of Northern Colorado, Greeley, CO. - Effects of magnesium chloride on Pinus contorta seedlings.
The objective of this study was to examine the effects of a spray
application of magnesium chloride on pine seedlings. Magnesium
chloride is used statewide in Colorado as a soil stabilizer on dirt
roads and de-icing agent for roadways in winter. Magnesium chloride is
replacing sodium chloride in these uses because of the reduced
corrosive effects. However, little is known about the physiological
effects of MgCl2 on roadside vegetation. With a controlled
greenhouse experiment, we examined the effects of four concentrations
of reagent-grade magnesium chloride (0 M, 0.74 M, 1.48 M, and 2.22 M)
and one treatment of the commercially available magnesium chloride at
the concentration applied to roads (3.15 M) on aboveground organs of
one-year-old Pinus contorta seedlings. Chlorophyll content,
shoot/needle dry weight biomass, and new needle growth at the apical
shoots were measured over a 60-day period. Thirty days after the first
spray application, necrotic needles were apparent on seedling exposed
to the three highest concentrations of MgCl2, and lower
chlorophyll contents were measured. Early results indicate that aerial
drift of magnesium chloride on roadside vegetation can have an impact
on pine health and vigor at the normal rates of commercial application
and lower rates.
Key words: magnesium chloride, Pinus contorta, seedling growth