[in Japanese]

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The present report gives the results on variation of some morphological and physiological characteristics among 24 ecotypes ofZoysia japonicacollected from all over Japan, ranging from Hokkaido (N 42°30') to Okinawa (N 26°10') .
The results obtained were summarized as follows:
1) . Significant variation in morphological characters, such as leaf blade length, leaf blade width, culm length and ear length were recognized among 24 ecotypes, that is, 10.1 to 20.4 cm in leaf blade length, 0.34 to 0.51 cm in leaf blade width, 7.2 to 15.0 cm in culm length and 3.2 to 4.9 cm in ear length. The large-sized type were ecotypes collected from Nagakute and Aso and small-sized type were Hokkaido and Iwate, many ecotypes of small-sized type were those collected from the districts of high latitude.
2) . The beginning of heading dates of each ecotype was ranged from April 4 to May 17. These heading dates were not related to temperature or day-length of collected districts.
3) . The sprouting period and beginning of top withering in winter was earlier in ecotypes collected from the districts of higher latitude than those collected from lower latitude.
4) . Characteristics in salt-tolerance, adaptability to heavy manuring and regrowth ability showed significant differences among some ecotypes.
5) . Generally, the growth increment in summer and autumn season was greater in ecotypes collected from the districts of lower latitude or altitude than those collected from higher latitude or altitude.

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This paper presents the result of investigation on the effects of seeding rate, cutting height and light condition on the growth performance of Astoria bentgrass, a cool-season turfgrass.
1) The number of tillers increased with time and was not adversely affected by rise of temperature during the period under review (42°55N, 143°13E) .
Low seeding rate and low level cutting deserved a vigorous tillering while shading diminished tillering increasingly with the lapse of time.
2) The number of leaves per stem decreased in accordance with the increase of tillers but it was hardly affected by cutting height and shading.
3) The growth pattern responded well to seeding rates, namely, more procumbent growth with low seeding rate and more ascending growth with high seeding rate.
High level cutting naturally assured a better growth later on.
4) An analysis of variance reveals clearly a significant correlation between plant density, cutting height and the growth performance of turfgrass.

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In concurrence with surveying seasonal prevalence of moths by light traps for forecasting set in turfgrass grounds of Ohya Golf Center, pesticides were sprayed at the imago stage of Bluegrass webworm, Shibatsutoga, in 1975 and also at the larval stage directly after hatch in the second generation in 1976.
In 1975, the control of imagines in the first generation was insufficient due to emergence of a number of imagines in the second and third generations. The control effect at the imago stage of each generation was as low as 20% of the estimated emergence.
In 1976, the control test using Karphos Emulsion was carried out for larvae directly after hatch in the second generation. Without the expected abnormal emergence, the number of imagines at the peak of the emergence curve was depressed to 446 with a greatly increased control effect by which the emergence of imagines was decreased to approximately 11% of the expected emergence at the third generation.
To control Bluegrass webworm, it would be necessary for a pesticide capable of retaining residual effect over a long period to be sprayed on a fine day subsequent to completion of the emergence in the first generation.
Control of Japanese lawn grass cutworm by pesticide spray in 1976 reached so high that the emergence of imagines was rarely observed in the third generation.

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1) Isoxathion was tested on tifgreen and tifway in theCynodongroup, which was sensitive to isoxathion application under unfavourable condition in our previous studies, in the regular and double dosage under field condition.
2) Isoxathion 50 EC was sprayed on tifgreen at the dosage of 0.25g/m²and 5g/m²in May 31, June 20 and July 11, and on tifway at the dosage of 0.25g/m²and 5g/m²in May31, June 10, 20, 30, and July 11. However, neither tifgreen nor tifway were not sensitive to isoxathion in this study.

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