An isolate All ofPseudomonas fluorescens, a bacterium antagonistic toT. ishihariensis, was isolated from sclerotia of the latter fungus which was harvested from golf courses. The difficulty existed in distinguishing this specific isolate from a large population of the nativeP.fluorescenswhich is a common habitant in the turf when this isolate was sprayed on to the turf. To survey the survival rate of sprayed All in the turf, a daughter isolate, named A11RN, which was tolerant to both rifampicin and nalidixic acid was induced from the parent A11 colonies on media including these antibiotics. The sod-cup test suggested that 4×10⁸cfu/cm²of All and All RN in culture liquid suppressed mycelial growth of T. ishihariensis.
The spray of All and A11RN in culture liquid to golf courses effectively suppressed the snow mold disease caused byT.ishihariensis. These suppressive effects were higher than those of the fungicide and increased with the elevated densities of the sprayed isolates. An isolation test showed that A11RN, which had been sprayed to the turf of golf courses just before a snow season, survived in the turf until the end of April of the next year, although its population gradually diminished before the snow melted. The present experiments proved that All would be a candidate to develop a new, commercial antagonistic microbe complex, which is effective to control the snow mold in golf courses.

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We studied the effects of pyroligneous acid (PA) on the growth of turfgrass using several culture methods.
1) Seeds water culture: PA accelerated the root elongation at 0.01%-0.25% for kentucky bluegrass (KB), at 0.01%-0.1% for bentgrass penncross (BC) and bentgrass penneagle (BE), and at 0.05% for bentgrass pennlinks (BL), whereas PA reduced the shoot growth in concentration-dependent manners. At higher concentrations (>0.5%), PA strongly inhibited the root elongation. Therefore 0.05% PA is adequate for the shoot and root growth of the turfgrasses tested.
2) Sods water culture: PA at a concentration of 0.05% promoted the root elongation of the sods of bentgrass penncross (BC), kentucky bluegrass (KB) and manilagrass (ML) regar Bless of pH control of culture solution. PA inhibited the root elongation at >0.25% and pH 6.25 for BC, at >0.25% and >0.5% for KB and ML, respectively regardless of pH control. At the concentrations ranging 0.01-0.5%, PA showed a promotive effect on the shoot growth, although the effect varied with the variety of turfgrass and the pH of culture solution. For KB and ML, PA at higher concentrations (>0.5 %) reduced the shoot growth regardless of pH control.
3) Soil culture; The effects of the monthly application of PA at 0.1-50l/a for one year on bentgrass penncross (BC), manilagrass (ML), Japanese lawngrass (JL) and kentucky bluegrass (KB) were evaluated. PA at 0.1-1l/a increased the foliar dry weights (FDW) of ML, JL and KB, but PA at 1l/a decreased the FDW of BC by 85% of the control. PA at 0.1-1l/a increased the root dry weights of all turfgrasses tested.
4) Cold tolerance: PA at 1-5l/a increased the cold tolerance of manilagrass.
5) These results suggest that PA, within optimum concentration ranges, has promotive and protective effects on the growth of turfgrass. We are conducting field trials to confirm these effects.

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Severity of the patch diseases of turfgrass was evaluated objectively by image analysis. An area of large patch disease was phtoguraphed on a color film. The color image was incoporated into a personal computer. Red color image which is one of the components of a color image was effective to distinguish the brown-colored patch area from the greencolored healthy area. Analysis of the red color intensity within tha patch area was consistent with disease severity of the area which was assessed by naked eyes. This analytical method was applicable to evaluate the control effects of a fungicide to large patch disease of zoysiagrass and also to compare disease resistance of bentgrass cultivars.

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Studies were held to demonstrate presence the root-knot nematode, Meloidogyne marylandi Jepson & Golden, parasitizing on improved bermudagrass (cv. Tifton 328) in Japan. Grass samples were collected from seven districts grown at nurseries or golf courses in four prefectures. The root-knot nematode was found from six district samples observed. This suggests that the nematode was commonly distributed everywhere of Tifton greens. To study for identification of the root-knot nematode species in each sample, the living materials were prepared respectively from a single egg-mass produced by matured female. Morphological investigations of second stage larvae and adult females were carried out by light and scanning electron microscopes. Biochemical assey by electrophoresis of female body was also examined. As results, we confirmed that each root-knot nematode material is only consisted with a species M. marylandi and not presence of another species M. graminis.

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Cupreous chafer, Anomala cuprea HOPE is a major scarab beetle pest of turfgrasses, nurseries of forest trees and many field crops. The larvae of A. cuprea feed on the roots of grasses and plants in the soil, and they are very difficult to control. We assumed to control A. cuprea by using joint action between an entomogenous fungus Metarhizinm anisopliae and insecticides.
Susceptibility of larvae of A. cuprea against M. anisopliae treated with stressors such as insecticides or entomogenous fungi were investigated. Fenthion and fenitrothion were effective to enhance susceptibility of 1 st instar of A. cuprea against M. canisopliae. period after treatment of P, fumosoroseus demonstrated no tendency for susceptibility of A. cuprea against M. anisopliae. M. anisopliae had the strongest pathogenisity againstA. cuprea, after 12 hr treatment of fenthion. Stressors established with very low concentration didn't affect on the mortality of A. cuprea treated with M. anisopliae.
These results showed that M.anisopliae treated with low concentration of organophosphates would become an effective control method against larvae of A. cuprea.

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In the use of the phytopathogenic bacteria Xanthomonas campestris pv. poae (JT-P482) as a bioherbicide to control annual bluegrass, a wound is necessary for the bacteria to enter the plant. In this paper, the relationship between wound treatments and efficacy is described. (1) The more wounds, especially in parts of the plant closer to the stem, the greater the efficacy obtained. Therefore, in putting greens, it is important to make annual bluegrass stand upright by using a thatchingreel mower or grooming techniques before mowing. (2) For efficient use, the interval between cutting and JT-P482 treatment should be as short as possible. In addition, if treatment is carried out under severe conditions (e. g. dryness) the cut & spray method is recommendable for practical use. (3) Changes in the bacterial numbers in annual bluegrass plants after repeated mowing (to a height of 1.5cm) were determined. Seven days after treatment, bacterial populations in plant tissue reached a maximum (10¹⁰ CFU/g FW)

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Italian ryegrass cultivar“Futaharu”and centipedegrass were considered to be suitable for covering soil surface between pineapple rows from the standpoint of soil conservation in Ishigaki island. Italian ryegrass and centipedegrass grew well within 6 months and by 1 year, respectively, after planted between pineapple rows. Since pineapple growth was reduced because of the height of the Italian ryegrass, it was considered that cover crops should be planted a little apart from pineapples.
To avoid competition between pineapple and cover crops and stabilize the emergence of cover crops, usage of two cover materials together with cover crops was examined. Consequently, cotton sheet combined with centipedegrass, laid 30cm apart from the pineapple rows, covered successfully soil surface between pineapple rows mulched with black vinyl sheet. However, the problem of the high cost involved and the difficulty of weed control remained to be resolved. This method is applicable for establishing turf stands in tropical and subtropical areas.

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