Influence of Growth Regulators on Ionic Thiocyanate Content of Cruciferous Vegetable Crops1

Abstract

Abstract Under greenhouse conditions, butanedioic acid mono-(2, 2-dimethylhydrazide) (daminozide) at concentrations of 100, 500, or 1000 mg/liter applied to ‘Burpee white’ radish (Raphanus sativus L.) and 500 or 100 mg/liter applied to ‘Snow Ball’ turnip (Brassica rapa L.), significantly increased root thiocyanate content. Concentrations of 1000 mg/liter gibberellic acid (GA), 500 mg/liter 6-benzylamino purine (BA), and 10 mg/liter 2,4-dichlorophenoxyacetic acid (2,4-D) also increased root thiocyanate content of both species. Under field conditions, applications of 1000 mg/liter daminozide, 1000 mg/liter GA, and 500 mg/liter BA increased root thiocyanate in ‘Burpee White’ radish, ‘Tokyo Cross’ turnip, and ‘Snow Ball’ turnip grown on both loam and organic soil. While there was no effect of these growth regulators on thiocyanate content in roots of ‘White Icicle’ radish, heads of ‘Early Green Ball’ cabbage (B. oleracea L., Capitata group), or ‘Green Mountain’ broccoli (B. oleracea L., Italica group), results for head thiocyanate content of ‘Waltham 29’ broccoli were inconsistent. Five of the seven crops grown on organic soil had thiocyanate contents that were higher than those grown on loam soil.