The purpose of this study is to look into the planting distribution of turfgrasses in Japanese golf-courses. The author investigated turfgrasses in golf-courses and the state of grass distribution, based upon the data collected from the responses to the guestions which were answered by 456 golf-courses. The results obtained summarized as follows.
1) The greater part of important turfgrasses of the world was founded in Japanese golf-courses.
2) Cool season turfgrass which belongs to Festucoideae is the best grass in Hokkaido, and is somewhat planted in the northern and central districts of Honshu. The middle type of warm season turfgrass which belongs to Eragrostoideae s planted in southern area from the south of Hokkaido, and warm season turfgrass which belongs to Panicoideae is sometimes used in southern area of Japan.
3) Penncross, cultivar of bentgrass which is presentative cool season turf grass, is planted in whole area of Japan. Its distridution is more extensive than the distribution of zoysiagrass which grows throughout the country.

View full abstract

1. The materials for analysis were collected one time per month from December 1986 to December 1987 by hole cutter from the No. 6 Penn-cross bentgreen, Koraigreen and Fairway at Hodogaya Country Club. The stem and leaf, the root of BG (Agrostis stolonifera L.: Pen-ncross bentgrass) in the bentgreen, the stem and leaf, the rhizome and the root of KG and FW (Zoysia matrella (L.) MERR: Manilagrass) in the koraigreen and the fairway were anali-zed on the dry matter weight and the nutrient contents: total carbohydrate, nitrogen, phosphoric acid, potassium, calcium, magnesium, sodium, manganese, iron, copper and zinc. The weight per one square meter was calculated on some of the components. From this data, outline of the seasonal changes of nutrient contents in the turfgrass were cleared.
2. The dry matter weight of the penncross bentgrass per unit area increased remarkably from April to August as the weight of roots of the penncross bentgrass increased rapidly in the periods. The dry matter weight of the manilagrasses in the koraigreen and the fairway per unit area increased since May as the rhizome began to grow. In this investigation, it was proved clearly to begin growing of the new roots of the penncross bentgrass from March, the manilagrasses in the koraigreen and the fairway from May.
3. The total carbohydrate in the stem and leaf of the penncross bentgrass decreased remarkably from April to October, but the reduction of carbohydrate in the stem and leaf of the manilagrass was smaller than the penncross bentgrass. The manilagrass is C4 plant to C3 plant of the penncross bentgrass. There was great difference of the photosynthesis in the both, the photosynthesis of the manilagrass was larger than the penncross bentgrass in summer season.
4. The inorganic component contents have generally a tendency to higher in the penncross bentgrass more than the manilagrass. The four components: manganese, iron, copper and zinc were contained remarkably high in the roots of the penncross bentgrass more than the manilagrass. There was great difference in total amounts of the four components per one square meter between the penncross bentgrass and the manilagrass. It was confirmed to be absorbed remarkably much in the penncross bentgrass more than the manilagrass in the absorption of the four components.

View full abstract

One of the major problems which occur on golf greens of manila grass (Zoysia matrella) during spring season in southern part of Japan is an irregular decay of turf surface resulting in deterioration of patting quality. This kind of turf damage has been considered to be caused by certain physiological factors unfavorable to the initiation of growth under low temperature circumstance. In this paper, we tentatively name such damage of turf surface “Fuzoroi-sho” and demostrate that the damage is not caused, at least in some cases, by physiological incidence of the grasses but is the result of infection by Pythium graminicola and Pythium vanterpoolii. Evidences supporting our proposal are as follows:
(1) Pythium graminicola (Pg), P. torulosum (Pt) and P. vanterpoolii (Pv) were mainly isolated from grass tissues and rhizosphere.
(2) Inoculation tests using seedlings of Zoysia japonica indicated that Pg and Pv were pathogenic under low temperature condition, even at 5°C, while Pt had no pathogenicity at the temperature range of 5 and 25°C.
(3) Treatments of the green by fungicides containing metalaxyl or hydroxyisoxazole and metalaxyl mixture at the early spring were remarkably effective to protect the truf surface from the damage. Number of sprouts remained on the turf and dry weight of stem and leaves were about twice as much as those of untreated control.
(4) Neither Pg nor Pv was detected from the grass tissues and rhizosphere after the treatment of the turf with these fungicides.
It was suggested that application of metalaxyl or hydroxyisoxazole at the early spring may provide effective control of Fuzoroi-sho.

View full abstract

We dealt with the effects of surfactants on herbicidal activity and the following results were obtained.
The nonyl phenol ethylene oxide surfactant (No.4) and the trimethyl stearyl ammonium salt surfactant (No.17) highly enhanced the activity of Asulam against annual bluegrass (Poa annua) .The HLB (Hydrophilic Lipophilic Balance) value of nonionic surfactants giving a maximum effect on Asulam was about 12.
Surfactants apparently enhanced the activity of Bialaphos. The number of ethylene oxide and the HLB values of nonionic surfactants giving higher effect on Bialaphos were in the range 8-12 and 12-14 respectively.
In general, the phytotoxicities of the four nonselective foliar-applied herbicides, Glyphosate, Bialaphos, Alloxidim and NaOCN, were increased by the addition of surfactants. Particularly, the highest joint action was observed with NaOCN and the degree of the joint action decreased in the order of Glyphosate> Bialaphos> Alloxydim.
The concentration of surfactants for a maximum enhancement of the herbicidal activities was in the range 0.1-0.3%.

View full abstract

The entomogenous nematodes, Steinernema feltiae, S. bibionis and S. glaseri, were almost uninfective against larvae of scarabaeid beetles. According to Ishibashi et al (1987), the infective juveniles (J₃) of S.feltiae (DD-136) were stimuleatd to move actively by low concentration (10-62.5ppm) of oxamyl.
Therefore, in this paper, the mixing applications of S. feltiae Mexican with the low concentration of chemicals were investigated against 3 instar larvae of Anomala schönfeldti. The mixture of Mexican (12×10⁵/m²) with fenitrothion (×1000, 5000, dil.) and diazinon (×1000, 5000, dil.) to larvae showed significantly higher potentiation than only insecticides on the tests. The mechanism of action by mixing application may be base on decrease of the larval defense against nematodes under the influence of insecticides.

View full abstract

[in Japanese]

View full abstract