The seeds ofZoysia japonicaSteud. were encapsulated with alginic acid gel after adding the gibberellic acid in concentrations of 0, 5, 10, 20 and 40 ppm. The encapsulated seeds were then incubated in pots at 25°C under light for 14, 21 and 28 days. The effects of the encapsulation on the germination and the early seedling growth of theZoysiaseeds were investigated by comparing the germination percentage, the plant length and the root length of the encapsulatedZoysiaseeds with those of the control seeds. The results are summarized as follows:
1) The germination percentage of the encapsulated seeds was larger than the control seeds when the addition of gibberellic acid was 10 ppm or more. The promotional effect of the encapsulation on the germination was marked when the amount of gibberellic acid added was 20 ppm.
2) The plant length of the seedlings from encapsulated seeds was higher than that of the control seeds in all cases when the addition of gibberellic acid was 5 ppm or more, i.e., on the 14th day, 2lth day and 28th day after seeding. The effect of the encapsulation on the promotion of the plant length was markedly observed when the amount of the gibberellic acid added was 20 ppm or 40 ppm.
3) The root length of the encapsulated seeds was somewhat shorter than that of the control on the 14 th day and 21 th day after seeding. The promotional effect of the encapsulation on the root length elongation was not apparent. However, on the 28 th day after seeding, the root length of the encapsulated seeds became equal to or exceeded that of the control.

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We investigated the good effects of artificially granulated soil (trade name: Kureha Shiba Ace) for the germination and growth of turfgrasses.
The granulated soil was artificially produced by drying several materials in hot air, and mixed with fine-pulverizing, and several fertilizers. After setting pH value, it was granulated and dryied again at a high temperature. This artificially granulated soil was superior to sand in water holding performance, fertilizer holding performance and the effect of raising geothermal and permeable rate.
The use of the artificially granulated soil as seed mixture and covering soil was studied in terms of germination state, germination rate and vegetative state, compared with the cases, where sand was the covering soil or not. The artificially granulated soil as the seed mixture and as the covering soil was obviously effective on the germination rate in comparison with the case of non-covering soil.
Compared with sand in the same way, the granulated soil showed a rise of about 20% in the germination rate (Fig.8) and of about 1.5 times in the growth (Fig.9) .

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Greenhouse studies were conducted to clarify the herbicidal properties of sulfonylurea herbicides (sulfometuron-methyl, flazasulfuron, pyrazasulfuron-ethyl) and imidazolinone herbicide (imazaquin), which were recently introduced for turfgrass weed control. And the following results were obtained:
1. Weed control spectrum
Three sulfonylurea herbicides at 5-10g/10 a and imazaquin at 20-40g/10 a were applied pre-emergence or post-emergence, and their herbicidal effectiveness was determined 30 days after their applications. Three sulfonylurea herbicides and imazaquin controlled a broad spectrum of annual weeds. The four herbicides applied post-emergence also controlled perenial weeds, such as Trifolium repens andKyllinga brevifolia. But these four herbicides could not effectively controlVeronica caninotesticulateandVicia sativa. Sulfometuron-methyl and pyrazosulfuron-ethyl were not effective against grass weeds. The herbicidal effectiveness of these four herbicides applied post-emergence treatment was relatively greater than that of the herbicides applied preemergence treatment.
2. Injury to turfgrass (Manilagrass, Zoysia matrella)
Sulfometuron-methyl caused unacceptable injury to Manilagrass both at emerging stage and at growing stage. Flazasulfuron and imazaquin moderately inhibited the growth of the turfgrass at emerging stage, but they slightly inhibited the growth of the turfgrass at growing stage. Pyrazosulfuron-ethyl did not injure the turfgrass either at emerging stage or at growing stage.
Sulfometuron-methyl moderately inhibited the photosynthesis of Manilagrass, but other three herbicides slightly or scarcely inhibited the photosynthesis. These four herbicides did not inhibit the respiration of the turfgrass.
3. Behaviours in soil
(1) Downward movement in soil
The downward movement of the herbicides accompanied with movement of water in soil was monitored by using bioassay technique. These four herbicides moved downward to 4-6 cm in the soil. The order of the rate of movement among the tested herbicides was sulfometuron-methyl>flazasulfuron>pyrazosulfuron-ethyl, imazaquin.
(2) Residual activity in soil
Residual effectiveness of the herbicides in soil was determined by using sensitive weeds. Sulfometuron-methyl persisted in the soil more than for 40 days, but pyrazosulfuron-ethyl, flazasulfuron and imazaquin disappeared in 30-40 days.

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Paclobutrazol was applied to retard elongation and growth of weeds in turfgrass field and its effect on elongation and growth of weeds were shown in Table 1 and 7.
The weight of annual emergence of weeds was restrained by yearly application of Paclobutrazol to 39-43% of the control plot to which Paclobutrazol was not applied (Table 2) . In the experiment turfgrass fields where Paclobutrazol was applied only in the first year, the emergence weight of weeds increased as years passed, but weight of the weed emerged in the second year was restricted to 51-63% (Table 2) .
In order to prove the effect of Paclobutrazol on emergence of individual species of weed, variation in emergence ofBromus catharticusvahl andDigitaria adscendensHenr was studied. The retarding effect of Paclobutrazol application on vegetative growth ofBromus catharticuswas prominent in emergence weight and elongation length. The physiological effect such as on flower-bud formation was also observed (Table 3 and 5) . The effect of Paclobutrazol application on vegetative growth ofDigitaria adscendenswas as conspicuous as in the case ofBromus cat harticus. However, the physiological effect such as on flowerbud formation was not clear (Table 4 and 6) .

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[in Japanese]

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