Effect of Cold Temperature and the Effectiveness of Glyphosate ((N-(phosphonomethy)Glycine) and 2,4-Dichlorophenoxyacetc Acid When Applied to Chickweed (Stelleria media).

Chickweed (Stellaria media) is a persistent winter annual that grows easily in gardens, low maintenance lawns and agricultural areas. Growing without competition, chickweed can produce approximately 800 seeds and it takes 7 to 8 years for 95% of the seeds to lose viability, ensuring infestation for many years. This research investigated the plant kill percentage using four herbicide treatments and a control 2,4-D, Glyphosate, and water alone, and a 2,4-D/glyphosate mix. They were applied in February at a daily temperature at 29°F. There were three replicates for each treatment, sprayed once. The replicates were analyzed on a weekly basis and the kill percentage was ranked from 0-10. Zero being 0% kill and 10 being 100% kill. The percent kill, was determined by observation. After seven weeks of observation the Roundup and Roundup/2-4 D mix had 100% kill, while the 2-4 D and water had zero kill. Surprisingly, at this temperature the 2-4 D had no effect on chickweed. The chickweed sprayed with 2-4 D and the chickweed sprayed with water had no difference in the growth. Future studies might see if chemicals might have a synergistic effect and improve 2-4 D’s ability to kill chickweed.