Influence of Pyrazon and Dalapon on the Seasonal Growth of Sugarbeets

Mixtures of 5-amino-4-chloro-2-phenyl-3(2 H )-pyridazinone (pyrazon) plus 2,2-dichloropropionic acid (dalapon) were applied to sugarbeets ( Beta vulgaris L.) at three growth stages 1 year and six growth stages another year. The growth of tops and roots was retarded most when sugarbeets were treated in the two-leaf stage of growth. The weight of tops and roots was reduced 43 and 50%, respectively, 6 weeks following an application of a mixture of 3 lb/A each of pyrazon and dalapon. However, when these sugarbeets were sampled 2 weeks later, the tops and roots weighed only 4 and 12% less, respectively, than the untreated controls. Furthermore, the early suppression in the growth of sugarbeets for 3 to 8 weeks following herbicide treatment had no effect on final yield of roots, pounds of sucrose, or sucrose content at harvest.