Published online by Cambridge University Press: 12 June 2017
The application of 2,4-D [(2,4-dichlorophenoxy) acetic acid], at 1.1 kg/ha to common dandelion (Taraxacum officinale Weber) resulted in 40% or less survival in lawn and hayfield habitats, in both spring and fall treatments. A significantly lower incidence of regeneration (12 to 20%) was attained independent of the season by shoot removal (spudding) combined with 2,4-D in the lawn, but not in the hayfield habitat. No measure of control was obtained by spudding alone, confirming the high capacity of common dandelion for root regeneration. Removal of leaves 2 weeks after application of 2,4-D diminished the effectiveness of control in both lawn and hayfield habitats, with 49 to 50% and 60 to 70% regeneration, respectively. Apparently, there is incomplete translocation of the herbicide within this interval. Significant mortality from spudding alone was observed only in plants less than 4 months old (64% survival). One-year-old plants responded to all treatments in the same manner as common dandelion populations as a whole. Optimum control of common dandelion in lawns was obtained by 2,4-D application in combination with spudding, during the spring.