Residue Safety on Ethephon in Soybean Leaf by Drenching and Foliar Application

Ethephon is useful pesticide as ethylene precursor, which is an efficient plant hormone to produce functional secondary metabolites. However, the residual safety of ethephon was not studied on various crops. In here, the dissipation pattern of ethephon residue in soybean leaf was investigated both on the foliar and drenching applications. The biological half-lives of ethephon residues were 26.6, and 21.1 h on the once, and double foliar applications, respectively. Although the residue after three days from the final application was up to 60.6 mg kg-1, the residue was below the limit of quantitation on the dried soybean leaf. In addition, drenching application of ethephon could increase the residue up to 36.3 mg kg-1 after 20.1 h from the application, however, the treatment would not affect to the total phenol content significantly (p >0.01).