The experiments were performed to evaluated the varieties of perennial ryegrass for overseeding grasses by turf qualites and simulated traffic resistance.
In ground cover, Common perennial ryegrass was reduced very early but Pennfine perennial ryegrass was maintained very well.
Leaf color was dark green in Pennf ine, Parcour and Linn perennial ryegrass, but Manhattan and Sprinter perennial ryegrass was lighter green during January to February.
Manhattan and Pennfine was made up the good putting surface which was fine texture and high shoot density.
Manhattan and Pennfine was superior on the cuttability, while Common and Linn remained many fibers on the cut leaf after mowing.
Italian ryegrass was the least putting quality, and Manhattan and Sprinter was the best.
Perennial ryegrass, which was the most tolerant of wear and compaction by simulated rolling treatments, was Manhattan perennial ryegrass.

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This experiment was carried out on the effect of microbial activity and decomposition of thatch by microbial de-thatching agent (Biseibutsu-bunkaizai S), and their multiplied activity against soil microflora. Microbial de-thatching agent contains micro-organisms which were saturated into dry material. The microorganisms were similar to natural organisms which decomposed organic matter.
Microbial de-thatching agent was tested on the changes of the number soil microflora of Trichoderma spp., Rhizopus spp., bacteria and actinomycetes in the sterilized soil, unsterilized soil and soil mixed with turf. The dilution plate method was used.
We subsequently studied on the time-course changes of the number of fungi under the sterilized soil as above mentioned that increased without microbial de-thatching agent. The influence on the number microflora was not clearly found by this treatment. But only among fungi, Trichoderma spp, andRhizopus spp. increased. The bacteria showed a rapid increase on number in early period by this agent treatment.
The number of fungi and bacteria of these genera in the unsterilized soil was increased by the treatmeut of microbial de-thatching agent. Moreover, an addition of turf to soil remarkably increased the number of the total micoflora. Among the microflora, Trichoderma spp. and Rhizopus spp. increased in the numder in the latest period, but bacteria was not increased by this treatment.

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1. We screened out C-MH (MH choline salt) for practical use from four salts of Maleic hydrazide, because it had the highest physiological activities in our many experiments and its herbicidal effctiveness was stable in various conditions.
2. We tested C-MH at 0.5-1.0% for perennial weed control in spring, summer and autumn in the fields.
Many perennials could not sprout next spring from reproductive organ of the underground portion by autumn application of C-MH.
Philadelphia fleabane, Kentucky bluegrass and dandelion etc. were severely damaged by early spring application. Many perennials recieved only a temporary setback by summer application and were recovered gradually. But cutting off or chemical killing of the overground portion of the perennials 1 week after summer application could inhibit the regeneration.
3. In the turfgrass tested, Manilagrass was damaged a little by C-MH application, but its elongation was inhibited for a long term by cutting off after its application. In this case, howtver, a very fine and green turf was formed with an increase in the number of tillers and leaves.Japanese lawngrass was sensitive to C-MH and was moderately damaged by its application. Bentgrass was more sensitive to C-MH and sometimes killed.
4. C-MH reached 0-3 cm of surface soil by rainfall or water supply. C-MH was easily inactivated in soil by soil micro-organism for about 1 week. The decomposition pathways nvolved : MH-N → NH₄⁺-N → NO₃^--N.
5. In autumn, MH was translocated from overground portion to underground portion of perennials in large quantities in about 1 week by C-MH spray application and was not decomposed till next spring, and then inhibited the sprouting.
As above-mentioned, in summer C-MH could not control the perennials, but inhibited the regrowth of the underground portion by cutting off the overground portion after MH application. For this reason, we first assume that in summer MH is considerably decomposed in leaves and stems, and we secondly estimate that MH inhibits cell division in the meristematic regions, but not cell enlargement, as similar phenomena are observed in the inhibition of sucker of tobacco plant.

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1. According to Dr. A. Mutsuura (Biosystematic Research Institute Agriculture Canada) and Dr. D. C. Ferguson (Systematic Entomology Laboratory, U. S. D. A.), bluegrass webworm is a turfgrass injurious insect, whose scientific name is Pediasia (Crambus) teterrellusZINCKEN and which is distributed in the central and eastern areas of the U. S. A. Recently this insect has intruded into Japan, causing damage to turfgrass. This paper proposes Shibatsutoga as the Japanese name for the webworm.
2. The damage to turfgrass is so serious that everyone can readily notice it if once any damage is caused by this webworm (Shibatsutoga) . Therefore, investigating the history of the damage is inevitable for the study on intrusion route of this webworm. The first damage to turfgrass in Japan was found inZoysia matrellawithin Sanda Golf Course (Sanda City, Hyogo Prefecture) . The first import of Tif ton 328·419 from Tifton, Georgia, U. S. A. into Japan was for Sengari Golf Course in Sanda City.
3. The webworm subjected the authors to the identification was collected from the Tif ton 328·419 in Hamamatsu Seaside Golf Course which had been imported from the United States into Sengari Golf Course. Consequently, the intrusion route of Bluegrass webworm into Japan was verified to be from Southern Turf Nurseries Co. Ltd., U. S. A. to Hamamatsu Seaside Golf Course via Sengari Golf Course.
4. Succeeding mass-import of the Tifton turfgrass by some company motivated this turfgrass to be mix-planted in nurseries for domestic turfgrass. Bluegrass webworm is concluded to have spread in Japan through such process. Plants such as live turfgrass should be imported with careful consideration for the import, after detailed investigation.

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In order to select the effective insecticides for control of moths injurious to the turfgrass, we have investigated the persistent effect of 15 insecticides against the larvae of the Japanese lawn grass cutworm, Rusidrina depravata (B) and bluegrass webworm, Pediasia (Crambus) teterrellus (Z) .
1. Comparing the persistent effect of these insecticides against the larvae of moths, S-3151, karphos (EC), and ortran (WP) are the greatest equally, and then come EPN, diazinon, sumithion, S-5602, salithion, paputhion in decreasing order.
2. The insecticidal formulation for control of these moths showed more effective to EC, WP than G, FG.
3. Dipel effectiveness of the Japanese lawn grass cutworm on turfgrass gave higher control of these early instars, but not the later stages.

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This paper presents the results of investigation on the inoculation tests of nine fungi isolated from turfgrass (Zoysiaspp.) at 12 golf causes of Chugoku and Kyushu district toZoysia matrella (L.) Merr. Results of this experiment were as follows.
When conidiospore suspensions of seven fungi were inoculated onto wounded leaves ofZoysia matrella (L.) Merr., necrotic lesions on the leaves produced byCurvularia lunata (Wakker) Boedijn, Trichodermasp., Phomasp., Fusariumsp. and Trichoderma viridePers. ex Fr., but not byCurvularia verruciformisAgarwall et Sahni andPenicillium purpurogeuumStoll var.rubri-scierotiumThom.
Wounded stems ofZoysia matrella (L.) Merr. at the somewhat upper portion of surface of soil were inoculated with fungi itself cultured by rice bran·wheat bran medium (rice bran: wheat bran: water=1: 1: 2) in two different seasons. According to the results of inoculation test on June, Curvularia verruci formisAgarwall et Sahni, Curvularia lunata (Wakker) Boedijn, Penicillium purpurogenumStoll var.rubri-sclerotiumThom, Trichodermasp., Phoma sp., Fusariumsp., Pithomyces maydicus (Sacs.) M. B. Ellis andTrichoderma viridePers. ex Fr. developed the symptoms on the stems and leaves in some plants out of inoculated plants, butFusarium oxysporumSheld. emend Snyder et Hansen did not develop. On the contrary, at the inoculation tests on FebruaryFusarium oxysporumSheld. emend Snyder et Hansen, Curvularia verruciformisAgarwall et Sahni, Penicillium purpurogcnumStoll var. rubri-sclerotium Thom, Phomasp., Fusariumsp., Pithomyces maydicus (Sacc.) M. B. Ellis andTrichoderma viridePers. ex Fr. developed the symptoms in all pants inoculated, moreover, these plants were seriously damaged.
It is likely that the method using of rice bran·wheat bran medium is very effective for the inoculation of fungi toZoysia matrella (L.) Merr. and its effectiveness, however, differs in seasons under natural conditions.

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In this study, Manilagrassin theZoysia-groupandTifgreenandTifwayin theCynodon-group, which showed sensitivity to isoxathion in the previous pot test, were tested under field condition in August 1976.
The odtained results were summarized as follows ;
1. Manilagrassdid not show any sensitivity to isoxathion.
2. Tifgreenshowed a little sensitivity (yellowing), but recovered in a few days.
3. Tifwayshowed higher sensitivity thanTifgreen. It srecovery was observed later then that ofTifgreen.

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Effect of three Kinds of Snow-Melting agents on the temperature change in turf was examined. In the temperature rise between the depth 0cm and 2cm, A agent was more effective than C agent, while B agent had little effect. However, there was little defference in the effectiveness to the depth lower than 4cm among these agents. Also, no significant difference was found among the agents on the temperature drop. Thus, A was most effective Snow-Melting agent, since the temperature of surface layer was the most important factor against Snow-Melting agent.

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