Abstract: In view of the nonstandard usage of fenaminosulf on singleharvesting Z.latifolia， the effects of different spraying periods， different concentrations and spraying times on yield and value of singleharvesting Z.latifolia were studied. The results show that in some regions where singleharvesting Z.latifolia could be harvested twice per year， fenaminosulf could significantly promote forming swollen gall， advance the harvest time for about 50 d. Fenaminosulf with 0.5 g·L-1 （a.i.） should be used at 150， 160 and 175 d after transplanting of Z.latifolia last year. In normal singleharvesting Z.latifolia growing regions， once application of fenaminosulf could obviously advance harvest time and improve yield and benefit， but with more frequency of use， yield and benefit of Z.latifolia decreased more significantly. In conclusion， fenaminosulf with 10 g·L-1 （a.i.） should be used only once at 4060 d after transplanting of Z.latifolia.

Key words: fenaminosulf, singleharvesting Zizania latifolia, yield, economic benefit