Herbicidal Effects on Water Uptake of Seeds of Selected Weed Species

Abstract

AbstractSeeds of yellow foxtail, johnsongrass, pigweed and quackgrass were investigated to determine the effects of certain herbicides on water uptake by these species. Seeds of johnsongrass showed slight increase in water uptake over the 20‐h period when treated with 1, 5, 10, and 500 mg/1 of 2,4‐D. Tordon caused a most pronounced increase in water uptake at 0.1 and 1 mg/l as compared with the controls. Johnsongrass gave indications of either increases or decreases in water uptake when treated with herbicides during the 20‐h period, but showed no effects during the 10‐h period. Dormant seeds of yellow foxtail indicated an enhancement in water uptake at all 2,4‐D concentrations during the 20 h period. The effects which the different herbicides had upon the uptake of water in yellow foxtail seeds seemed to be directly proportional to increase in imbibition time. In all cases, more water was imbibed after 20 h over that observed at 10 h. During the 10‐h imbibition period, pigweed seeds treated with 2,4‐D was noted to have a slight stimulating effect on water uptake at all concentrations employed except 5 mg/l, which indicated a depressing effect. It was also observed that 2,4‐D caused a significant stimulating effect on water uptake of pigweed seeds over the 20‐h period as compared with the controls. A stimulation in the total quantity of water imbibed after 20 h was noted at dacthal concentrations below 100 mg/l whereas at the 500 mg/l, a slight depression in water imbibition was observed. At dalapon concentrations of 1 to 100 mg/l, a marked stimulation in total water imbibed by quackgrass seeds was shown during the 10‐h period.