• Title/Summary/Keyword: clipping weight

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The Effect of Nitrogen Application and Clipping Interval on the Characteristics of Several Turf Components of Korean Lawn Grass (Zoysia japonica Steud.) (질소시용 및 예초간격이 한국 잔디(Zoysia japonica Steud.)의 제잔디 구성요소 특성변화에 미치는 영향)

  • 심재성;윤익석
    • Asian Journal of Turfgrass Science
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    • v.1 no.1
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    • pp.18-29
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    • 1987
  • This study was carried out to examine the effect of nitrogen application and clipping interval on the characteristics of several turf components of korean lawngrass for the basic data of lawn management. It was treated by Split plot design with three replications. The main plots were nitrogen levels with 0, 350, and 700kgN / ha, and the sub plots were clipping intervals with 10, 20, and 30 days The results obtained are summarized as follows ; 1. Increasing the rate of nitrogen fertilizer and frequent clipping increased tiller number of korean lawngrass and the maximum number of tillers obtained in October were recorded from 700kgN application and clipping treatment of 10 days interval. Meanwhile, treatment of 350kgN with 10 days clipping interval increased tillers much more than those of 700kgN with 20 and 30 days clipping intervals. 2. The average number of green leaves occurred during the growth period maximized by applying 700 kgN and clipping 10 days interval. 3. Increasing tiller numbers significantly decreased tops DM weight per tiller by clippng plants at interval of 10 and 20 days, irrespective of nitrogen applied, and with nil N, at the interval of 30 days. By applying 700kgN however, tops DM weight per tiller increased as the number of tillers increased consistently. 4. The highest tops DM weight was achieved from late August to early September by applying 350 and 700kgN. 5. During the growth period, nitrogen application increased unders(stolon+root) DM weight, and, at the same level of nitrogen applied, the increase in stolon DM weight enhanced by lengthening the clipping interval to 30 days. 6. Nitrogen efficiency to green leaves, stolon nodes and DM weight of root with high nitrogen was achieved as clipping interval was shortened.

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Studies on the growth of Korea Lawn Grass (Zoysia japonica Steud.)in Reponse to Nitrogen Application, Clipping Treatment and Plant Density (질소시용, 예초 및 재식밀도가 한국잔디(Zoysia Japonica Steud)의 생육에 미치는 영향)

  • Sim, Jae-Seong
    • The Journal of Natural Sciences
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    • v.1
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    • pp.61-113
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    • 1987
  • The increasing emphasis placed on the production of fine turf for lawns, golf courses, parks, and other recreational sites has led to many unsolved problems as to how such turf could be best established and mainteined. For this purpose, a series of experiments were conducted under con ditions of pot and field. The results obtained were as follows EXPERIMENT I. The effect of nitrogen fertilizer and clipping interval on Zoysia japonica. 1. Increasing the rate of nitrogen and frequent clipping increased tiller number of Zoysis japonica and the maximum number of tillers were obtained from 700 kg N application and freqnent clippings (10 days interval ) in October. Treatment of 350kg N with 10 days clipping interval increased tillers much more than those of 700 kgN with 20 and 30 days clipping intervals. 2. The average number of green leaves occurred during the growth period maximized by applying 700 kg N and clipping 10 days interval. 3. Increasing tiller numbers significantly decreased tops DM weight per tiller by clipping plants at interval of 10 and 20 days, irrespective of nitrogen applied, and with nil N, at the interval of 30 days. By applying 700 kg N, however, top DM weight per tiller increased as the number of tillers increased consistently. 4. The highest top DM weight was achieved from late August to early September by applying 350 and 700kgN. 5. During the growth period, differences in unders ( stolon + root ) DM weight occurred bynitrogen application were found between nil N and two applied nitrogen levels, whereas, at the same level of nitrogen applied, the increase in stolon DM weight enhanced by lengthening the clipping interval to 30 days. 6. Nitrogen efficiency to green leaves, stolon nodes and DM weight of root with high nitrogen was achieved as clipping interval was shortened. 7. By increasing fertilizer nitrogen rate applied, N content n the leaves and stems of Zoysiajaponica was increased. On the other hand, N content in root and stolon had little effect onfertilizer nitrogen, resulting in the lowest content among plant fractions. The largest content of N was recorded in leaves. Lengthening the clipping interval from 10 or 20 to 30 days tends to decrease the N content in the leaves and stems, whereas this trend did not appeared in stolon androot. 8. A positive correlations between N and K contents in tops and stolon were established andthus K content increased as N content in tops and stolon increased. Meanwhile, P content was not affected by N and clipping treatments. 9. Total soluble carbohydrate content in Zoysia japonica was largest in stolon and stem, and was reduced by increasing fertilizer nitrogen rate. Reduction in total soluble carbohydrate due to increased nitrogen rate was severer in the stolons and stems than in the leaves. 10. Increasing the rate of nitrogen applied increased the number of small and large vascular bundles in leaf blade, but shortened distance among the large vascular bundles. Shortening the clipping interval resulted in increase of the number of large vascular bundles but decrease ofdistance between large vascular bundles.EXPERIMENT II. Growth response of Zoysia japonica imposed by different plant densities. 1. Tiller numbers per unit area increased as plant density heightened. Differences in num ber between densities at higher densities than 120 D were of no significance. 2. Tiller numbers per clone attained by 110 days after transplanting were 126 at 40D,77 at 80D, 67 at 120D, 54 at 160D, and 41 at 200D. A decreasing trend of tiller numbers per clone with increasing density was noticable from 100 days after transplanting onwards. 3. During the growth period, the greatest number of green leaves per unit area were attainedin 90days after transplanting at 160D and 200D, and 100 days after transplanting at 40D, 80Dand 120D. Thus the period to reach the maximum green leaf number with the high plantdensity was likely to be earlier that with the low plant density. 4. Stolon growth up to 80 days after transplaning was relatively slow, but from 80 daysonwards, the growth quickened to range from 1.9 m/clone at 40D to 0.6m/clone at 200Din 200 days after transplanting, these followed by the stolon node produced. 5. Plant density did not affect stolon weight/clone and root weight/clone until 80 daysafter transplanting. 6. DM weight of root was heavier in the early period of growth than that of stolon, butthis trend was reversed in the late period of growth : DM weight of stolon was much higherthan that of root.EXPERIMENT Ill. Vegetative growth of Zoysia japonica and Zoysia matrella as affected by nitrogen and clipping height. 1. When no nitrogen was applied to Zoysia japonica, leaf blade which appeared during theAugust-early September period remained green for a perid of about 10 weeks and even leavesemerged in rate September lived for 42 days. However, leaf longevity did not exceed 8 weeks asnitrogen was applied. In contrast the leaf longevity of Zoysia matrella which emerged during the mid August-earlySeptember period was 11 weeks and, under the nitrogen applied, 9 weeks, indicating that thelife-spen of individual leaf of Zoysia matrella may be longer than that of Zoysia japorica. Clipping height had no effect on the leaf longevity in both grasses. 2. During the July-August period, tiller number, green leaf number and DM weightof Zoysia japonica were increased significantly with fertilizer nitrogen, but were not with twolevel of clipping height. This trend was reversed after late September ; no effect of nitrogen wasappeared. Instead, lax clipping increased tiller number, green leaf number and DM weight. Greenleaves stimulated by lax clipping resulted in the occurrance of more dead leaves in late October. 3. Among the stolons outgrown until early September, the primary stolon was not influencedby nitrogen and clipping treatments to produce only 2-3 stolons. However, 1st branch stoIon asaffected by nitrogen increased significantly, so most of stolons which occurred consisted of 1st branch stolons. 4. Until early September, stolon length obtained at nil nitrogen level was chiefly caused bythe primary stolons. By applying nitrogen, the primary stolons of Zoysia japonica waslonger than 1st branch stolons when severe clipping was involved and in turn, shorter than 1stbranch stolons when lax clipping was concerned. In Zoysia matrella, 1st branch stolons were muchlonger than the primary stolon when turf was clipped severely but in conditions of lax clippingthere was little difference in length between primary and 1st branch stolons. 5. Stolon nodes of both Zoysia japonica and Z. matrella were positively influenced by nit rogen, but no particular increase by imposing clipping height treatment was marked in Zoysiamatrella. Although the stolon of Zoysia japonica grew until late October, the growthstimulated by nitrogen was not so remarkable as to exceed that by nil N.

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The Effect of Nitrogen Fertilization on the Growth and Thatch Accumulation of Colonial Bentgrass grown under Removing Clipping Residues (예초잔여물을 제거하지 않은 조건에서 질소의 시비가 Colonial Bentgrass의 생육과 Thatch 축적에 미치는 영향)

  • 이주삼;윤용범
    • Asian Journal of Turfgrass Science
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    • v.5 no.2
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    • pp.69-73
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    • 1991
  • This experiment was carried out in order to study the effect of nitrogen fertilization on the growth of Colonial bentgrass and thatch accumulation under no removing clipping residues. Nitrogen fertilization was applied as 4 levels, 10, 20, 25 and 20gN/m$^2$, respectively. The results were as follows : 1.Response of plant length and dry weight of thatch to N fertilization were significant differences between N levels. It suggested that N fertilization with no clipping residues greatly affected to the growth and thatch accumulation of colonial bentgrass.2.Plant length, the dry weight of clipping residues and coverage were obtained the highest values at 20g N. It was assumed that 20gN/m$^2$ is the limiting N level to obtain the favorable growth of Colonial bentgrass. 3.The dry weight of thatch and lignin content were increased with high nitrogen fertilization level. 4.The dry weight of thatch indicated positive significant correlation with lignin content. 5. The dry weight of thatch per N(THg/N) at 20g~25g/m$^2$ levels were obtained the lowest values than of other levels of N. It may be due to the stimulating of microbial activity by adequate to N fertilizers which increased mineralization of thatch.

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Effect of nitrogen application and clipping height on the vegetative growth of Korean lawn grass (Zoysia japonica Steud.) and Manilagrass (Zoysia mat rella (L.) MERR.) during September/October (질소시용 및 예초고가 한국 잔디(Zoysia japonica Steud.) 및 금잔디(Zoysia matrella MERR.)의 생육후기 영양생장에 미치는 영향)

  • 심재성;윤익석
    • Asian Journal of Turfgrass Science
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    • v.1 no.1
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    • pp.7-17
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    • 1987
  • The experiment with two levels of nitrogen (0. and 300kg / ha / year) and two levels of clipping height (1.5cm and 4cm) was conducted on the field during the period 3 June to 23 October 1985. Clonal lines of korean lawngrass ( Zoysia japonica Steud.) and manilagrass ( Zoysia matrella ( L.) Merr.)of Daejon origin were established in June, as individual clone in rows 30cm apart with a 40cm spacing between clones, actually 4 clones each plot. The results obtained were as follows : 1. When no nitrogen was applied to korean lawngrass, leaf blade which appeared during the August / early September period remained green for a period of about 10 weeks and even leaves emerged in late September lived for 42 days. However, leaf longevity did not exceed 8 weeks as nitrogen was applied. In contrast the leaf longevity of manilagrass which emerged during the mid - August / early September period was 11 weeks and, under the nitrogen applied, 9 weeks, indicating that the life - saen of individual leaf of manilagrass may be longer than that of korean lawngrass. Meanwhile, clipping height had no effect on the leaf longevity in both grasses. 2. During the July / August period, tiller number, green leaf number and DM weight of korean lawngrass were increased significantly with fertilizer nitrogen, but were not with two levels of clipping height. This trend was reversed after late September : no effect of nitrogen was appeared. Instead, lax clipping increased tiller number, green leaf number and DM weight. Green leaves stimulated by lax clipping resulted in the occurrance of more dead leaves in late October. 3. The increase of tiller number, green leaf number, and DM weight of korean lawngrass due to nitrogen application appeared to be of significance in early September. Unlike korean lawngrass, however, this significant increase was maintained to late October when new green leaves still emerge. Clipping height had little effect on the growth of manilagrass by early September, but since then, lax clipping stimulated leaf appearance, possibly resulting in a remained green color of manilagrass turf. 4. Among the stolons outgrown until early September, the primary stolon was not influenced by nitrogen and clipping treatments to produce only 2 - 3 stolons. However, 1st branch stolon as affected by nitrogen increased significantly, so most of stolons which occurred consisted of 1st branch stolon. 5. Until early September, stolon length obtained at nil nitrogen level was chiefly caused by lengthening the primary stolons. By applying nitrogen the primary stolons of korean lawngrass was longer than 1st branch stolons when severe clipping was involved and in turn, shorter than 1st branch stolons when lax clipping was concerned. In manilagrass, 1st branch stolons were much longer than the primary stolons when turf was clipped severely but in conditions of lax clipping, there was little difference in length between primary and 1st branch stolons. 6. Stolon nodes of both korean lawngrass and manilagrass were positively influenced by nitrogen, but no particular increases by imposing clipping height treatment was marked in manilagrass. Although the stolon of korean lawngrass was grown until late october, the growth stimulated by nitrogen was not so remarkable as to exceed that a by nil N. 7. The thickness of korean lawngrass and manilagrass was greatest in late September, but that of manilagrass did not differ significantly from that in late October. 8. The response of stolon length of korean lawngrass to lax clippings was not so great in late October as to that to severe clippings. On the other hand, the positive effect of lax clippings to stolon length in m anilagrass was confirmed even in late October.

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Studies on the Flowering and Maturity in Sesame (Sesamum indicum L.) IV. Effects of Foliage Clipping on the Seed Maturity (참깨의 개화.등숙에 관한 연구 IV. 적엽처리가 참깨의 등숙에 미치는 영향)

  • Lee, Jung-Il;Kang, Chul-Whan;Son, Eung-Ryong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.30 no.2
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    • pp.165-173
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    • 1985
  • The objectives of the study were to investigate the effects of foliage clipping on photosynthesis and grain filling for branch and non branch types under the polyethylene film mulch and non mulch conditions in mono cropping and second cropping after barley in sesame (Sesamum indicum L.), and to improve poor grain filling at later flowering time utilizing these data. One thousand grain weight was more decreased in branch type than in non branch type, in polyethylene film mulch condition than in non mulch condition, and in second cropping after barley than in mono cropping by clipping lower part foliage. Twentyfive percent clipping of lower part foliage showed a little increase than no clipping. Matured grain rate also showed same tendency between branch and non branch type and between mono cropping and second cropping after barley as well as 1,000 grain weight except for polyethylene film mulch. Matured grain rate of 25% foliage clipping at 30 days after flowering in non branch type presented a little increase but decreased in branch type. Clipping of higher part leaves were so serious decrease of matured grain rate that higher part leaves at late maturing time have a major role in photosynthesis. Matured grain rate of foliage clipping at 10 days after flowering was decreased in all treatments. Chlorophyll content of higher part leaves at 50% lower part foliage clipping presented 39% increase compared to same positioned leaves of non treatment, and 66% increase by 50% higher part foliage clipping in lower part leaves. Photosynthetic activity was 58% more increased in 50% lower part foliage clipping than no clipping, but seriously decreased in 50% higher part foliage clipping. Therfore, photosynthates of remained lower part leaves could not only support their own demands, but also any contribution to translocation of photosynthates from source to sink at late maturing time. Harvest index was 28% increased in 25% lower part foliage clipping and 13% decreased in 50% higher part foliage clipping compared to no clipping. Leaf area was 48% increased in 50% lower part foliage clipping compared to the same positioned leaves of no clipping, and only 5% increased in higher part foliage clipping. Productivity by foliage clipping compared to non treatment, was highly decreased in branch type than in non branch type, in second cropping after barley than in mono cropping. Little difference was detected between polyethylene film mulch and non mulch conditions. Twenty five percentage of lower part foliage clipping on mono cropping of non branch type appeared 5% and 8% yield increase in each of polyethylene film mulch and non mulch conditions compared to no clipping, and all decreased in other treatments. Mean loss of productivity by foliage clipping at 10 days after flowering was serious than clipping at 30 days after flowering. As the result, contribution to photosynthesis of source at 10 days after flowering are larger than that at 30 days after flowering in sesame. Fifty percent lower part foliage clipping at 10 days after flowering showed so the most serious yield decrease that lower part leaves at that time were considered as the main role leaves for photosynthesis.

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Effects of Clipping on Growth and Yield in Sweet Potato (고구마 경엽절제가 생육 및 수량에 미치는 영향)

  • 김익제;손석용;이재웅;유인모;이철희;김태수
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.47 no.3
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    • pp.143-146
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    • 2002
  • This study was undertaken to learn what ratio of clipping top was the most optimum for minimizing of the decrease of root yield of over 50g in sweetpotato at early cultivation. The test variety was "Shinyulmi" which was transplanted for early cultivation on April 18. The ratios of cripping top were 5, 10, 15, 20, and 25 percents. The date of clipping top was June 20 when the shoots were transplanted for double cropping. The total length of vine, the number of branches per plant, the number of tuberous roots over 50g and average root weight over 50g were not affected by clipping top. The ratio of root yield over 50g was lower over 20 percents of clipping top. The fresh weights per plant of top and bottom were similar as compared control with 15 percents of clipping top. In conclusion, the optimum ratio of clipping top was 15 percents for maximizing of the production of the shoots in sweetpotato for double cropping. cropping.

미숙아와 신생아의 동맥과 개존증에 대한 수술요법(소개흉 결찰술과 흉강경 보조하의 clipping과의 비교)

  • 장지원;한재진;원용순;원태희;안재호;박영식;최수승
    • Journal of Chest Surgery
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    • v.33 no.1
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    • pp.26-31
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    • 2000
  • Background: This study was aimed at analyzing the preoperative conditions post-operative results indication and methods of surgical closure of patent ducturs arterio년 in prematures low birth weight infants and neonates. Patients and Methods: We retro-spectively studied two groups of patients (prematures group and neonates group) who underwent surgical closure of the patent ductus arteriosus between March 1995 and June 1998. Results: The premature group consisted of 9 patients(3 males and 6 females) Their mean gestational period was 30.7 weeks(ranging from 26 weeks to 33 weeks) mean age 27.8 days(11 days to 55 days) and mean body weight 1.56 kg. Prominent preoperative symptoms were dependency on mechanical ventilation generalized edema and hepatomegaly. We performed PDA ligation via thoracotomy in all premature patients. The neonate group consisted of 16 patients and their mean body weight was 3.75 kg. Major symptoms of this group was tachypnea and intercostal retraction resistant to medical treatment. We performed video-assisted PDA clipping to them all. There were no postoperative complications or operation-related mortality in both groups. Comparing the ratio of size of PDA(mm)/body weight(kg) the ratio of premature group (ligation through thoracotomy) was higher than that of neonate group ( video-assisted clipping) that is 3,89:1.21(p=0.03) Conclusion : We conclude that the surgical closure of PDA can be a safe method of treatment for prematures low birth weight infants and neonates with compromised general conditions. Choice of surgical technique depends on the surgeon's preference but there was a tend-ency to choose the ligation method through thoracotomy for patients with small body weight and large PDA.

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Effect of Clipping Time on Seed Maturity and Germination in Italian Ryegrass (Lolium multiflorum Lam. Italicum) (이탈리안라이그라스 예취시기가 종자 등숙 및 발아에 미치는 영향)

  • 서석기;김영두;박호기;박문수
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.1
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    • pp.104-111
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    • 1997
  • Since seeds of Italian ryegrass should be imported every year, it is necessary to investigate the prossible production of seeds in Italian ryegrass field after rice. Seven Italian ryegrass varieties were planted on October 8, 1986 at National Honam Crop Experiment Station at Iksan and clippings were made on April 10 and April 30 in 1987. Headings of K-11 and T.N.T were earlier than those of Tetrone and Bettina. For all varieties tested, heading date was delayed and 1,000 grain weight was decreased linearly as the clipping was made later. Length, width and thickness of a grain were reduced by clipping and later clipping, while tetraploid varieties produced larger grains than diploid varieties. The germination percentage and germination speed at $25^{\circ}C$ were higher than at 15$^{\circ}C$. The final germination percentage was lower at the later clippings and was higher at 15$^{\circ}C$, and earlier varieties showed higher germination percentage. Uniformity of germination was greater at $25^{\circ}C$ and was decreased as the clipping was made later, and the eariler varieties such as K-11 were germinated more uniformly. Average number of days to germination was longer at 15$^{\circ}C$ than at $25^{\circ}C$ and was longer at later clipping. The germination percentage was decreased linearly as the heading was delayed, while it increased linearly as the 1,000 grain weight was increased.

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The Effect of Foliage Clipping on the Growth and the Agronomic Characteristics, as Affected by its Time, Degree, and Nitrogen Top-Dressing, in Rice plants (절엽의 시기 및 정도, 그리고 절엽 후의 시비가 수도의 생육 및 수량제형질의 변화에 미치는 영향)

  • Eun-Woong Lee;Yong-Woong Kwon;Pyeong-Ki Yim
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.4 no.1
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    • pp.81-91
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    • 1968
  • To investigate the effects of foliage clipping time, degree, and nitrogen top-dressing after clipping on the growth and the agronomic characteristics, rice plants grown under ordinary cultural practices were clipped at the maximum tiller stage, 10 days prior to, and after that stage, respectively, with varying clipping, height, as 0, 1/3, 1/2, and 2/3 of plant height. And nitrogen was top-dressed at the rate of 0, 2, 4, 6 kg per 10 are immediately after clipping. The variety used was "Jinheung". The results obtained are outlined as follows: 1. Effect of clipping on the growth of rice plant: The subsequent growth was quite rapid during 10 days after clipping, and resulted, on the whole, in nearly complete recovery of defoliation by 20 days after clipping. a) Generally, the later the clipping time, the more growth accelerated. Rice plants clipped before the differentiation of ear primordia nearly recovered the damage, and in certain cases exceeded non-clipped plants in height. But the height of the rice plant clipped after the differentiation of ear primordia was somewhat smaller than that of non-clipped. b) Growth rate was rather rapid in the case of severe cutting, and the height of slightly clipped plants was taller than that of non-clipped plants. However, rice plants clipped to the extent of 2/3 of plant height did not fully recover the damage of defoliation compared to non-clipped plants. c) Nitrogen dressing was effective to rapid recovery of defoliation, the effect increasing with the increasing amount of application. d) Ear-heading was delayed in clipped plots, and this tendency was more apparent with later clipping time, more severe clipping, and increased amounts of nitrogen application after cutting. The range was 6 days at maximum. 2. Effect of defoliation on the yield and its components of rice plants: The yield response to clipping varied somewhat with its time, degree, and nitrogen application after cutting: yield increase of about 10% and decreasement of about 25% at maximum compared to the control plot. Grain yield of most plots was decreased. a) Clipping before the differentiation of ear primordia did not much affect the agronomic characteristics of rice plants. However, clipping after that growth stage decreased culm length, number of panicles, number of spikelets per panicle, and maturing rate of grain to some extent. Consequently this treatment resulted in decrease of about 10% in grain and straw production in spite of increase in panicle length and effective tillering rate. b) Slight, clipping decreased number of spikelets per panicle a little, and the yield of grain and straw by 4-5%, although effective tillering rate was somewhat increased. With severe clipping, panicle kngth, number of panicles, and number of spikelets per panicle decreased more, and the yield of grain and straw decreased about 10%. c) Nitrogen dressing after clipping at the rate of 2 kg per 10 are was effective in increasing grain yield. Nitrogen application over the rate of 4 kg per 10 are increased culm length, number of spikelets per panicle, and straw production, but this decreased the maturing rate, and the 1, 000-grains weight to some extent and resulted in decrease of grain yield.

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The Growth and Thatch Accumulation of Kentucky Bluegrasses as Affected by Cutting Management. Varietal Differences under Removing Clipping Residues (예초관리에 따른 Kentucky bluegrass의 품종간의 생육과 Thatch 축적 I. 예초잔여물의 제거 하에서의 품종간의 차이)

  • 윤용범;이주삼
    • Asian Journal of Turfgrass Science
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    • v.6 no.1
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    • pp.29-37
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    • 1992
  • This experiment was carried out in order to study the changes of morphological characters of the growth and thatch accumulation in :3 varieties of Kentucky bluegrass under removing clipping residues as affected by cutting management. The varieties used were Park, Kenhiuc and Newport.The results obtained are as follows; 1. The dry weight of leaf. stem and number of tiller was highest at 22. June and lowest at 21. Aug in alt varieties. And then the dry weight of rhizome, root and thatch increased with growth progressed) Tabte 3). 2. The relationship of the dry weight of biological yield and number of tillers was quadratic ally increased in the growth stage of spring($R^2$= 0.982**), and linearlly increased in the growth stage of autumn(r 0.944*)(Fig. 1). :3. The dry weight of thatch increased as an exponentially equation in alt :3 varieties of Kentucky blue-grass(Fig. 2). Thatch increased rate(TIR) can used to estimate the specifying a quantity of thatch accumulation from the turf. Thatch increase rate equation as follows. where TH$_2$ is the dry weightof thatch at T$_2$ survey time and TH$_1$ is the dry weight of thatch at $TH_1$ is the dry weight of thatch at $T_1$ survey time. $TIR(mg/cm^2/day)=\frac{Ln\;TH_2 - Ln\; TH_1}{T_2 - T_1}$ 4. Correlation coefficients between the dry weight of thatch and leaf weight was -0.633(P>0.05), and number of tiller of tillers was -0.666(P>0.5), respectively. It means that thatch accumu-lation increased with growth depression of leaf and stem.

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