Abstract
The purpose of this experiment was to evaluate the effect of the application to soil of herbicides in drained paddy fields in which naked barley being cultivated and where Stellaria alsine GRIMM var. undulate OHWI grew actively. Effects of single -or combined- applications to soil of several herbicides on the weeding efficacy and growth and yield of naked barley were investigated. The results obtained are as follows.
1. Trifluralin was more effective in controlling S. alsine, but less effective in controlling gramineous weeds than the combination of benthiocarb·prometryne. The combined application of trifluralin+prometryne and trifluraline+simazine was more effective in controlling gramineous weeds than the single application of trifluralin. Yield of naked barley was not affected by the treatment with these herbicides.
2. In the case of soil application performed immediately after seedling, photosynthesis and growth of barley were remarkably decreased by the application of photosynthetic inhibitors sach as simazine, prometryne and diuron, and slightly decreased by the application of chrolopropham and dichrobenil, but not by trifluralin.
3. Photosynthesis was decreased by the combined application of trifluralin+simazine, trifluralin+prometryne and trifluralin+diuron at early growth stages in barley, but the inhibition was removed as barley plant grew. Photosynthesis and growth of barley were markedly inhibited by the combined application of trifluralin+simazine.
4. The combined application of trifluralin+prometryne was effective in controlling S. alsine and gramineous weeds in paddy fields.
