Effects of Two Wetting Agents on Germination and Shoot Growth of Some Southwestern Range Plants

Abstract

Two soil wetting agents (linear sulfonate and alkyl polyethylene glycol ether) were evaluated on inhibition of germination and shoot growth of alkali sacaton, galleta, blue grama, and fourwing saltbush. Sacaton and galleta seeds were germinated in wetting agent solutions (185, 370, and 740 ppm by volume) as well as in sand and a water-repellent coal mine spoil sample treated with the wetting agents at rates equivalent to 23.5, 47, 94 liters/ha. Blue grama and saltbush were germinated only in the sand and spoil samples. Results indicate that in solution culture these wetting agents reduce germination, severely deter shoot growth of both sacaton and galleta, and cause nearly permanent injury to plumules of galleta seeds. Wetting agents applied to sand at the comparable rates cause only minor reduction in shoot emergence and growth of the tested grass species, presumably due to soil sorption of wetting agents. The wetting agents tested are potentially phytotoxic, especially the sulfonate compound to saltbush, but can improve shoot emergence when applied to water-repellent media.