The effect of storage conditions (storage in soil, air-drying at 30°C, air-drying at outdoor temperature and air-drying at 5°C) on the seasonal changes of seed germination in Kyllinga brevifolia Rottb. ssp. brevifolia under continuous dark and light conditions and at differrent temperatures (15°C, 20°C, 25°C and 30°C) were studied.
The storage conditions influenced the germination of the seeds under continuous light conditions: the germination percentage of the seeds stored in soil was higher than that of the seeds under the other three storage conditions, and it was higher in the following order, air-drying at 30°C < air-drying at outdoor temperature < air-drying at 5°C. Under continuous dark conditions, seeds stored in soil for 5 to 7 months were able to germinate, unlike those under the other three conditions.
The variation in the percentage of seed germination at 30°C and under continuous light conditions in two taxa of K. brevifolia Rottb., ssp. brevifolia and ssp. leiolepis were also studied. Fresh seed germination percentage of most clones of ssp. brevifolia exceeded 80 percent. Fresh seed germination percentage of ssp. leiolepis varied among clones. After 5 months of storage in soil, the seeds of the two taxa showed a high germination percentage.

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Based on the morphological differences of spikelets, 330 clones of Kyllinga brevifolia Rottb. collectede from Kuwana country club (Kuwana city, Mie) were divided into three taxa, ssp. leiolepis, ssp. brevifolia and their intermediate type. Subspecies leiolepis lacks teeth or shows one spinulose tooth on the scale kee lof the spikelets, whereas ssp. brevifolia shows several teethon the scale keel of the spikelets. In the intermediate type, the spikelets exhibit one tooth or several teeth.
Clones of ssp. leiolepis and the intermediate type fairway and rough parts of turf. Oh the other hand, clones of ssp. brevifolia were not distributed in the green and tee parts. In the tee, rough and fairway parts, the former two taxa and ssp. brevifolia generally infested apart from each other.
There were no differences in the dry weight of the shoots and total fresh weight of the spikelets among the three taxa of K. brevifolia. The length of the involucral scale bract relative to the rachis length of ssp. leiolepis and the intermediate type decreased with the increase of the plant length while that of ssp. brevifolia was constant.
Heading time of ssp. brevifolia was evidently earlier than that of the other two taxa. The 100 kernel weight was the lightest in ssp. brevifolia among the three taxa, and the weight of ssp. leio-lepis was slightly lighter than that of the intermediate type. The germination percentage of the fresh seeds of almost all the clones of ssp. brevifolia exceeded 80%. On the other hand, the germination of ssp. leiolepis and the intermediate type showed highly clonal variation.

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Effects of pyrazosulfuron-ethyl [ethyl 5-[[3-(4, 6-dimethoxypyrimidin-2-yl) ureido] sulfonyl]-1H-1-methylpyrazole-4-carboxylate] on the growth and activity of acetolactate synthase in rice (Oryza sativa) and C. serotinus plant were investigated. The growth of root and shoot was suppressed more remarkably in C. serotinus than in rice. In vitro, the enzyme activity from each organ of both plants was highly and similarly sensitive to pyrazosulfuron-ethyl; however, in vivo the activity was reduced more remarkably in C. serotinus organs after treatment with pyrazosulfuron-ethyl. Only in rice shoot was the reduction of enzyme activity in vivo remarkably recovered as a function of time after treatment. It is presumed that the primary site of action of pyrazosulfuron-ethyl is acetolactate synthase, and that its selectivity depends on the difference in degree of inhibition on acetolactate synthase activity in vivo as a function of time.

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Phytotoxic activity of the thiocarbamate herbicide dimepiperate (S-1-methyl-1-phenylethyl piperidine-1-carbothioate) and its effect on plant metabolism were investigated. The chemical was highly selective against tested monocotyledonous plants. Rice and corn showed strong tolerance, while barnyardgrass and crabgrass were susceptible to the herbicide. Dicotyledonous plants were tolerant.
Dimepiperate (10^-5M) reduced ¹⁴C-acetate incorporation into lipid fraction in leaf disks of barnyardgrass more than 30% at 60min after incubation. Lipid synthesis inhibitor, cerulenin, caused the same level of reduction of the acetate incorporation at 10^-5M, and this incorporation was inhibited even with 10^-6M dimepiperate.
Reduction of ¹⁴C-leucine and ¹⁴C-glucose incorporation into protein and cell wall fraction, respectively, were detected at 120min with 10^-5M. None of RNA and DNA synthesis, photosynthesis or respiration was affected by the herbicide. The results suggest that the primary site of action of dimepiperate is in the lipid synthesis pathway.

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In order to select suitable materials for measuring the activity of acetolactate synthase (ALS) preparation from plant sources, ALS was extracted from various cultivated plants and the enzyme activity was assayed throughout a year. Several compounds were screened to obtain ALS inhibitors by using ALS from selected plants.
1) The leaves of the following plans were found to be suitable materials for measuring the ALS activities: Brassica campestris var, rapa cv. komatuna, Bracssica compestris var. pekinensis cv. santousai and in spring and early summer respectively, cabbage (youg leaves), radish and rice in summer, and spinach, rye and rice in autumn.
2) There was no significant correlation between the planting season and the amount of acetolactate detected by the ALS assay, but the plant growth stage was related to the ALS activity.
3) Acetoin formation was detected in most of the plant materials by the ALS assay.
4) Chlorsulfuron-insensitive ALS was detected in several plants and assumed to be the ALS isozyme.
5) 2-(Methylthio) nicotinic acid, duroquinone and 2, 3-dimethoxy 1-1-, 4-benzoquinone inhibited the ALS prepared from barley as well as the growth of rice.

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The phytotoxic activity of glufosinate and the amount of ammonia accumulated during the application of the herbicide were compared among cucumber, rice and corn seedlings.
The plant seedlings were grown in Kasugai's nutrient solution until the 1-st true leaf stage (cucumber) and the 2.8 leaf stage (rice and corn). The roots of the plant were immersed in a glufosinate solution for one hour. Growth of the seedlings was suppressed and chlorosis of leaf margins was observed after the application of more than 2mM glufosinate.
Effect of glufosinate on the plant seedlings grown with different nitrogen sources (NH⁺₄-N, NO^-₃-N or none) was also analyzed. Although the rate of growth inhibition differed slightly with the difference in the nitrogen sources in the medium, the growth of all the plant species was retarded by the application of 2mM glufosinate and chlorosis of the leaves was observed at 2 days after treatment. The ammonia content increased in all the plant seedlings after the herbicide treatment, suggesting that the type of chemical and amount of absorbed nitrogen did not contribute to the herbicide action of glufosinate. Since a C₄ plant (corn) was injured in the same way as C₃ plants (cucumber and rice), it is assumed that photorespiration also may not be related to the herbicide action.

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No experimental evidence of hybridization between Cyperus iria L. and C. microiria Steud. has heretofore been documented, though occurrence of natural interspecific hybrids in the genus Cyperus has been reported by Koyama (1953, 1961). The authors have obtained new types of plants from an experimental field after a mixed planting of these two species. The new plants showed an intermediate form between the two in shape of floral scale and floret density. They were longer in spikelet length and had a greater number of florets, though seed fertilities were evidently lower than those of the parent species. The seeds of new plants were dormant in each of the reciprocal crossings between C. iria and C. microiria, and the dormancy could be broken by a stratification at 15°C for one month. This character was considered to have been inherited from the dormant parent C. microiria. Progenies of the new type plants also showed a clear segregation in the characters of spikelet and floret morphology. It can thus be confirmed that these plants obtained from mixed planting in the experimental field are to hybrids between C. iria and C. microiria.

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