2001 Volume 29 Issue 2 Pages 115-120
The herbicidal activity of cafenstrole (N, N-diethyl - 3 - mesitylsulfonyl - 1 H - 1, 2, 4 -triazole - 1 - carboxamide, Fig.1.) was evaluated for use as a new turf herbicide and the results were as follows:
1. Cafenstrole effectively controlled annual grassy weeds such as Digitaria ciliaris, Digitaria violascens, Setaria viridis and Poa annua at the dosage of 5 g a.i./a by pre-emergence application under upland conditions (Table 2, 3) . But when cafenstrole was applied post-emergence, herbicidal activities against Digitaria ciliaris and Poa annua were decreased (Fig. 2, 3) .
2. No phytotoxicity was observed even at the dosage of 200g a.i./a of cafenstrole by foliar application to Zoysia matrella and Zoysia japonica but slight phytotoxicity was observed on Agrostis stolonifera at the dosage of 20g a.i./a (Table 4) .
When cafenstrole was applied just after the transplanting of turf grasses, phytotoxicity of cafenstrole to Zoysia matrella and Zoysia japonica and growth inhibition of their roots were not observed (Table 5) .
The phytotoxicity of cafenstrole to Zoysia matrella and Zoysia japonica after four successive foliar applications was not observed (Table 6) .
3. Mobility of cafenstrole in soil was determined by a bioassay using a soil column. The movement of cafenstrole in the soil seemed to be very limited. It was assumed that most of the cafenstrole applied remained in the 1-2cm layer under the soil surface and the mobility of cafenstrole was less than that of simazine (Fig. 4) .
In conclusion, it was suggested that cafenstrole is a useful pre-emergence herbicide for the control of annual grassy weeds in Zoysia japonica and Zoysia matrella.
