Experiments were made to clarify the relation between resistance of turfgrass against sulphur dioxide and its environmental temperature.
Turfgrasses used as test samples are: Japanese lawn grasses No-shibaZoysia japanicaSteud.
Bentgrasses Highland bentgrassAgrostis tenuisSibth.
Penncross bentgrassA. patustrisHuds.
The outline of the results obtained are as follows :
1) No-shiba : As in the past experiments little damage is recognized on No-shiba with this method applied of sulphur dioxide treatment, and therefore no effects of temperature upon the damage can be observed in this experiment.
2) Highland bentgrass : With high temperature a damage is observed on the grass, whereas with low temperature no damage shows. So the authors can see that in case of this species the damage is clearly aggravated by high temperature.
3) Penncross bentgrass : As in case of Highland bentgrass, with high temperature the damage is greater. Results were studied with different temperature given before and after the sulphur dioxide treatment. High temperature aggravates the damage in either case. Low temperature given before the treatment lessens the damage considerably. Also, those given medium temperature before the treatment, the damage is smaller if the same medium temperature is given also after the treatment. From this the authors can see that the small variation of temperature -in the adequate range of temperature for the growth of turfgrass-makes damage smaller.

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In 1977, necrotic rings of fairy ring onZoysia matrellaL. are recognized at the golf course of Yachiyo Country Club, Hiroshima Prefecture. From these fairy ringsLepista snbnuda HONGO. is detected at the portion of plant roots area in the soil andHelminthosporium sp. is detected at the necrotic leaves, stems and roots of the plant. The Difolatan, N- (1, 1, 2, 2-tetrachloroet-hylthio) -4-cyclohexene-1, 2-dicarboximide, was effective to cure the disease at the concentrations of 1 to 250, 500 and 1, 000.

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1. This experiment was carried ont on the controlling effects of some soil-fungicides against bentgrass brown patch caused by Rhizoctonia solani using the artificial inoculation method in pots.
2. As the result of the experiments using Captan and TMTD against brown patch, lesions appeared 6-12 days after spraying in spite of their dosages, but afterwards area of lesions increased slowly.
3. To indicate the residual effects of some soil-fungicides used. controlling indices were measured. 50% reduction point of Captan, TMTD and TPN appeared after approximately 6 days, and that of TPN, mixture of Captan ·TMTD and TMTD was observed between 3-6 days. 50% reduction point of Polyoxin was observed after more than 12 days.
4. The fungicidal effect in soil of Captan and TMTD was determined by measuring of number of fungi isolated from treated soil. Continuous treament of soil for 6 days with Captan 2g/m², TMTD 2g/m²and TPN 1.5g/m², decreased number of fungi isolated greatly.

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Damage by the chestnut brown chafer, Adoretus tenuimaculatus Waterhouse, which discharges soil to enter turfgrass grounds, has recently increased. This grub is an important pest injuring the roots of turfgrass. To clarify the life history and seasonal prevalence of this chafer in the Tokai district, insects in each stage were reared under various conditions.
1. Adults were captured by a light trap from early May to early October. The peak of adult emergence is the middle of September. The adults collected in early May laid eggs immediately and the 1st generation emerged in early August. From the emergence curve of specimens captured in the light trap, the number of generations of this species is one per year.
2. From the results of rearing experiments in the laboratory, the adults of the 2nd generation emerged October. It is generally thought that almost all adults of the 1st generation winter in fallen leaves; a part of the 2nd genaration winters with adults and grubs.
3. The adults are active in the daytime, feeding on the leaves of the chestnut persimmon.They copulate and oviposit in turfgrass grounds. The adults are longlived. The lengths of the egg, larval, and pupal stages do not differ between the overwintering adult and the 1st generation. The average percentages of egg hatch and adult emergence are both 80%. The period from oviposition to adult emergence is about 60 days.
4. After first-stage larvae hatch in 12 days, they molt three times and become pupae. The development of this chafer is fast: third-stage grubs were observed for about 30 days. At 20°C, 25°C, and 30°C rearing temperatures, dormancy was not observed in any stage and adult emergence continued until December.
5. Compared with other species, this chafer can be raised easily. In the future, this insect can be reared in all seasons by using artificial foods. The chestnut brown chafer is also considered to be an important test insect for the study of soil insecticides.

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CAT (2-chloro-4, 6-bis (ethylamino) -s-triazine) has been used most commonly in turfgrasses for many years except bentgrass. But turfgrasses are sometimes affected by CAT, when it rains heavily after the application, or when CAT is applied in slops.
The writers found the solutions of the problems by using SANPEX CE 15 which is urethane resin emulsion.
1) The herbicidal effectiveness of CAT was greatly increased by the adding of SANPEX emulsion for a long period of time.
2) CAT plus SANPEX emulsion was distributed in the soil surface which is far from the root zone of Manilagrass, so CAT did not affect the turfgrass.
3) In other experiments, SANPEX was able to inhibit the vapourization of trifluralin, 2, 4-PA (ester) and DBN from soil, and also inhibit the downward movement of DPA and atrazine in soil.
4) In conclusion, the writers now consider as follows.
CAT is held physico-chemically on SANPEX and gradually dissolves in soil water, and controls weeds, so CAT is not easily inactivated in a short period of time and does not move deep in soil.
5) The writers are now studying the behabiour of SANPEX in soil and improving the formulation of CAT plus SANPEX.

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1. The results of questionnaire show that 77. 4 per cent of the golf courses are damaged by“earthworms”and that the owners who want to kill them are 65 per cent of all.
2. Since the earthworms begin to move actively when it continues to rain, the damages by them are noticeable in the rainy and the typhoon seasons.
In order to select the effective insecticides to control the earthworms on the golf courses, we have investigated the insecticides and the insectifuge powers of chemicals.
3. As for the insecticide power, it has proved that Teasaponine, TSG7703, TSG7704, and PHC are the most efficacious on the earthworms, and Methomyl and CVP are secondly. However, MEP, Cartap, Acaricides, Nematocides, and Fungicides have no effect on them.
4. Concerning the insectifuge power, Teasaponine, Lime Sulphur mixture, and TSG7704 are successful. Fungicides, generally, show this power, too.
5. Towards morning, the earthworms move about near the surface of the ground. Accordingly, we should sprinkle the water containing the efficacious chemicals above on the ground, especially on the casts. And we should do this in the early morning.

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