This study has as its objective the application of the plant growth regulator to the control of turfgrass cultivation.
In this paper, we will report on the experiment which we carried out in order to specify the effects of 6-Benzylaminopurine-a synthetic Cytokinin-on the germination of Highland bentgrass; BLUETAG (Agrostis tenuis Sibth), Bermudagrass; U3 (Cynodon dactylon L.), Kentucky bluegrass; COMMON (Poa pratensis L.) and Creeping red fescue (Festuca rubra L.) as well as on the initial growth in elongation of their roots.
6-Benzylaminopurne's effects on the growth in elongation of the turfgrass roots were most striking when its composition ranged from a conceotration of between 5×10^-9M and 5×10^-5M.
With regard to its effects on the germination of the seeds (dipping treatment), it was discerned that it promoted germination at a concentration of 5×10^-9M.
With a concentration of 5×10^-7M or higher, it showed a tendency to inhibit germination.
Moreover, with a concentration of 5×10^-6 M or above, its effects inhibiting germination were particulary prominent.
As concerns the effects of the 6-Benzylami-nopurine treatment on the growth in elongation of the roots in the first stage of germination, it was discerned that it promoted an increase in the number of roots at a concentration of 5×10^-9M.
In the case of a high concentration of 5×10^-7M or above, it showed a tendency to inhibit the growth of the roots in number as well as the growth in elongation of the roots.
When treating with 6-Benzylaminopurine after cutting the roots artificially, it was discerned that it promoted growth in elongation of the roots and increase in the number of roots at a concentration level of 5×10^-9M.
In other words, one can can conclude that 6-Benzylaminopurine, at a conentration of 5×10^-9M, promotes, while at a concentration of 5×10^-7M or 5×10^-6M or higher inhibits the gemination of seeds, the growth of new roots and growth in elongation of the roots.
It was observed that the sensitivity to 6-Benzylaminopurne of the various kinds of turfgrass used in this experiment differs according to species.
Among the various types of turfgrass, Creeping red fescue's sensitivity to 6-Benzylaminopurine proved high while that of Highland bengrass was low.
From the results obtained through this experiment, we can infer that 6-Benzylaminopurine influences the initial growth of the tufgrass by promoting the increase in the number of roots and the growth in elongation immediately after germination.

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This paper presents the results of investigation on the inoculation test of fungi of the fairy rings on turfgrasses. Lepista sordida (Fr.) Singer which separated from the Zoysia grass in the golf course of the Hiroshima Kokusai Golf Club, Hiroshima Prefecture and Marasmius oreades (Bolt, ex Fr.) Fr, which separated from the Kentucky bluegrass in a private garden in San Francisco, U.S.A. were used in this experiment.
The stems of Zoysia matrella (L.) Merr. and Poa pratensis L. (Kentucky bluegrass), wounded at the somewhat upper portion of the surface of soil, were inoculated with fungus itself which has been cultured by rice and wheat bran medium (rice bram: wheat bran: water=1: 1: 2) . The inoculated plants were put in the chamber at 25°C with artificial illumination. The results of the inoculation test show that Lepista sordida (Fr.) Singer developed the symptoms on the stems and leaves of almost all plants of inoculated Zoysia matrella (L.) Merr., but of few plants of Poa pratensis L.; and that Marasmius oreades (Bolt. ex Fr.) Fr. developed the symptoms in some plants of Zoysia matrella (L.) Merr., but almost never developed on Poa pratensis L.

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1. This experiment was carried out to find the effect and the residual effect, as well sa the spraying efficiency, of SKKF-1 [trichlophosmethyl, active ingredient, 0, 0-dimethyl -0- (2, 6 dichloro-4-methylphenyl) phosphorothiorate] when it was used as a fungicide on Zoysia Rhizoctonia large patch in the golf course faiway.
2. When SKKF-1 of 1.5-2g/l/m² was sprayed at the intervals of two or three weeks during vernal and autumnal disease seasons, the disease did not occur throughout the seasons.
Even when the spraying was halted halfway, the residual effect was witnessed.
Moreover in the next seasons, occurrences of the disease were delayed.
3. When the amounts of 0.5, 1. and 4g/l/m² of SKKF-1 were sprayed respectively prior to the vernal disease season, the outbreak was restrained for one and a half to two months in spite of the amounts.
When SKKF-1 of 1g/l/m² was sprayed at the interuals of three, four, six and eight weeks respectively throughout the seasons in spring and in autumn, satisfactory control of the disease was made at the intervals of six and eight weeks.
Consequently, it is suggested that the one to three times spraying of SKKF-1 can effectively control the vernal and autumnal outbreaks of the disease.
4. When SKKF-1 of 1g/m² was diluted by 300 and 500cc/m² water respectively and was sprayed by the running sprayer, the outbreak was controlled perfectly even with the quantity of 300 cc/m².
On the other hand, when 333cc and 500cc of SKKF-1 diluted 1000 times were sprayed respectively the outbreak was restrained perfectly even with the quantity of 333cc/m².
Consequently, this fungicide can effectively be used in small amounts of water and can be sprayed by the running sprayer like herbicides.
5. SKKF-1 of lg/300cc/m² mixed with the preemergent harbicide was sprayed by the running sprayer either with or without the spreader at the first spraying of the vernal spraying season.
The occurrence of the disease and the emergency of weeds were prevented in spite of the addition of the spreader.
Consequently, the number of the sprayings can be cut down by mixing the two pesticides.
6. When SKKF-1 of 1g/l/m² was sprayed on the disease-infected turf, the spread of the disease was prevented.
Consequently, SKKF-1 can be effectively used against the already present disease.

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1. This report was conducted to discuss the pathogens which cause spring dead spot of zoysia turfgrass from the anti-fungal effect of fungicides on the market.
2. The fungicides which showed restraining effects on this disease were TPN, captan, manzeb, iprodione, trichlophosmethyl (SKKF-1) and PCNB. Echlomezol, on the other baud, showed no effect.
The research on the anti-fungal range of those fungicides proved that the fungicides which restrained this disease showed the anti-fungal effect on Rhizoctonia, while the fungicide with the antifungal on Pythium did not halt this disease.
The research on the anti-fungal range of several already-reported fungicides also supported this test result that the fungicides with the restraining effect on spring dead spot were the ones which were effective against Rhizoctonia.
To confirm this, anti-Rhizoctnia fungicides, thiophanate-methyl and benomyl, and anti-Pythium hydroxyisoxazol were also exanined.
The results were the same, i, e., anti-Rhizoctonia fungicides showed restraining effect on the disease.
In this experiment, however, thiophanatemethyl and benomyl, both effectiue through system, did not show the supposed effect.
This was probably due to the fact that the turf was dormant thus preventing those fungicides to be penetrated.
It was also found that, with fewer number of sprayings during the disease season, trichlophosmethyl (SKKF-1) which warks solely against Rhizoctonia showed stronger residual effectiveness than TPN which had the antifungal effect on Pythiun, Fusarium and Rhizoctonia.
3. When the pathogens were separated from the disease. Rhizoctonia solani could be taken out from the infected turf but not from the uninfected one. Other pathogens were separated both from the infected and uninfected ones.
Rhizoctonia solani, separated from this disease, grew best at the temperature of 25°C.
This temparature is lower than that of Zoysia grass large patch.
4. The symptoms of spring dead spot were similar to these of large patch, both of which were caused by Rhizoctonia.
5. To conclude, spring dead spot of Zoysia grass is caused by Rhizoctonia solani.
However, this rescarch was performed on the disease which occurred in our field.
Further testing has to be made to determine whether or not spriug dead spot is caused by Rhizoctonia elsewhere.

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The following pre-emergence herbicides, such as nitraline (4- (methylsulfonyl) -2, 6-dinitro-N, N -dipropylaniline), terbutol+MCP (2, 6-di-tert-butyl-p-tolyl-methylcarbamate+2-methyl-4-chlorophenoxy acetic acid), siduron (I, - (2-methy-lcyclohexyl) -3-phenylurea), DCPA (dimethyl tetrachloroterephthalate), bensulide (0, 0-diisopropyl phosphorodithioate S-ester with N- ( 2-mercaptoethyl) benzenesulfonamide), and acephenone (4-tert-butyl-2, 6-dimethyl-3, 5-dinitroacetophenone) were applied for testing their safety to penncross bentgrass.
In Septemher 18 and Sept. 30, 1982, above 6 herbicides were applied on the penncross bentgrass nursery (established in 1979 with seeding, seedbed soils are sandy loam) on th golf cours of Okayama Mitsu C.C., in Japan.
Topdressing and aeration performed on the plots of herbicides in that nursery in October 18, 1982. The results are as follows.
(1) In case of before topdressing and aeration. Terbutol+MCP (1.6g/m²) caused chlorosis 2-3 weeks after application, however the others did not cause chlorosis.
(2) In case of after topdressing and aeration. Nitralin (0.5g/m² and 1.0g/m²), terbutol+MCP (0.8g/m² and 1.6g/m²) and DCPA (2.0g/m² and 4.0g/m²) injured the turf, 4-5 days after topdressing and aeration, at the plots where applied in Sep.18 and Sep.30. These plots were destructive in turf, especially nitralin (1.0g/m²) and terbutol+MCP (1.6g/m²) killed the root systems of penncross bentgrasses, however, which have not been dead. The turfgrasses recovered completely from damage in November. The other herbicides, such as siduron (1.8g/m² and 3.6g/m²), bensulide (2.0cc/m² and 4.0cc/m²) and acephenone (2.0cc/m² and 4.0cc/m²) were safety to the turf (penncross bentgrass) .
From above, we conclude that bensulide and acephenone can be used for annual bluegrass (Poa annua L.) control on penncross bentgrass greens on golf courses in Japan.

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1. Degradation of Asulam in soil.
Asulam [methyl N- (4-aminophenylsulfonyl) carbamate] was rapidly decomposed by microorganisms in the soils in a relatively short period. The rapid disappearance of asulam occured in the volcanic ash soil with about 30% of initial concentrations during 14 days after the treatment.
2. Adsorption and desorption of Asulam.
Asulam was not adsorbed to any marked extent by the soils, but was adsorbed in large amount by the thatch and the turf leaves, and asulam was more easily released from the leaves than the thatch.
Asulam was adsorbed strongly by humic acid and lignin, which were major components of humus, and the desorption from these components was a little.
3. Downward movement of Asulam in soil.
Asulam easily moved downward in many different soils after artificial rainfall. But it hardly moved in organic soils, clayish soils and thatch accumulated soils, because it was strongly adsorbed in these soil surface.
Asulam moved downward deeply in wet soils, but moved to a lesser extent in dry soils.

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This study was conducted to clarify the effect of the combination from atrazine and chlorophthalim on their herbicidal activities. An synergistic action from this combination was found in the herbicidal activity against several weed species. Crabgrass of 1.5 leaf stage was not controlled by atrazine at the dosage of 80 g/10a or by chlorophthalim at the dosage of 240g/10 a. However, the combination from atrazine, 40g/10a, and chlorophthalim, 120g/10 a, controlled it perfectly.
Furthermore, bluegrass of 4.5 leaf stage could be controlled by the cmbination.
pre-emergence herbicidal activity of the combination using three different soils was tested and it was found that the activity decreased with increase of clay content. From this, these herbicides may be adsorbed well by the clay.
pre-emergence application on fourteen weed species in a field trial, dayflower, crabgrass, foxtail and ladythumb were not controlled by atrazine at the dosage of 60g/10a, and dayflower, chickweed, knapweed, marshess and ladythumb were not controlled by chlorophthalim at the dosage of 150 g/10a. However, aforementioned combination from atrazine and chlorophthalim controlled all weebs except dayflower.
Phytotoxicity on turf grass (Zoysaa matrella) was not recognized even at the dosage of 100g/10a of atrazine and 200g/10a of chlorophthalim, respectively. Accrdingly, this herbicidal combi-nation from atrazine and chlorophthalim was found to be favourable for weed control in turf.

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(1) In indoor tests concerning Japanese beetles, DDVP, MEP, methomyl, salithion and isoxathion were found to have strong contact Poison and stomach poison effects. However, in residual effect tests by outdoor application, DDVP and salithion had almost no residual effects.
Insecticides which showed relatively good residual effects were isoxathion, methomyl, NAC, PMP, DEP, the last three not showing strong insecticidal activity in the indoor tests. It is to be noted that said insecticides had effects only for a short period of about one week, and in the rain the effects were rapidly reduced because the insecticides ran off from leaves.
The addition of sticking agents increased effects in case of wettable insecticides such as NAC and PMP.
Against chestnut brown chafers and pale brownish chafers and pale brown-ish chafers, chlorpyriphos showed the strongest insecticidal activity indoor, MEP, isoxathion and NAC showing the second strongest insecticidal activity indoor.
Japanese beetles were stronger against insecticides than chestnut brown chafers and pale brownish chafers.
(2) In food attractant tests of Japanese beetles, 12, 065 were captured in two months by means of one trap set in a golf course in which there were Japanese beetles in large puantities.
The number of captues much differed according to the places of the traps. It would be necessary to carefully study where to set the traps.
(3) To deuease damages to turfgrass dy Japanese beetles, it would be effective to reduce the density of Japanese beetle larvae dy controlling adult Japanese beetles by means of a good combination of attractants and insecticides.
Because insecticides at present do not have a long residual effect, it would be necessary to study how to make the period of the residual effect longer.

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