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Michio Sunairi - One of the best experts on this subject based on the ideXlab platform.
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burkholderia bannensis sp nov an acid neutralizing bacterium isolated from torpedo grass Panicum repens growing in highly acidic swamps
International Journal of Systematic and Evolutionary Microbiology, 2011Co-Authors: Tomoko Aizawa, Mutsuyasu Nakajima, Pisoot Vijarnsorn, Michio SunairiAbstract:Two strains of acid-neutralizing bacteria, E25T and E21, were isolated from torpedo grass (Panicum repens) growing in highly acidic swamps (pH 2–4) in actual acid sulfate soil areas of Thailand. Cells of the strains were Gram-negative, aerobic, non-spore-forming rods, 0.6–0.8 µm wide and 1.6–2.1 µm long. The strains showed good growth at pH 4.0–8.0 and 17–37 °C. The organisms contained ubiquinone Q-8 as the predominant isoprenoid quinone and C16 : 0, C17 : 0 cyclo and C18 : 1ω7c as the major fatty acids. Their fatty acid profiles were similar to those reported for other Burkholderia species. The DNA G+C content of the strains was 65 mol%. On the basis of 16S rRNA gene sequence similarity, the strains were shown to belong to the genus Burkholderia. Although the calculated 16S rRNA gene sequence similarity of E25T to strain E21 and the type strains of Burkholderia unamae, B. tropica, B. sacchari, B. nodosa and B. mimosarum was 100, 98.7, 98.6, 97.6, 97.4 and 97.3 %, respectively, strains E25T and E21 formed a group that was distinct in the phylogenetic tree; the DNA–DNA relatedness of E25T to E21 and B. unamae CIP 107921T, B. tropica LMG 22274T, B. sacchari LMG 19450T, B. nodosa LMG 23741T and B. mimosarum LMG 23256T was 90, 42, 42, 42, 45 and 35 %, respectively. The results of physiological and biochemical tests including whole-cell protein pattern analysis allowed phenotypic differentiation of these strains from previously described Burkholderia species. Therefore, strains E25T and E21 represent a novel species, for which the name Burkholderia bannensis sp. nov. is proposed. The type strain is E25T ( = NBRC 103871T = BCC 36998T).
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acidocella aluminiidurans sp nov an aluminium tolerant bacterium isolated from Panicum repens grown in a highly acidic swamp in actual acid sulfate soil area of vietnam
International Journal of Systematic and Evolutionary Microbiology, 2010Co-Authors: Kenichiro Kimoto, Tomoko Aizawa, Mutsuyasu Nakajima, Kenichiro Suzuki, Makoto Urai, Nguyen Bao Ve, Michio SunairiAbstract:An aluminium-tolerant bacterium, strain AL46T, was isolated from a waterweed, Panicum repens, grown in a highly acidic swamp (pH 3) at an actual acid sulfate soil area of Vietnam. Cells were Gram-negative, aerobic, non-spore-forming, non-motile rods (0.3 μm wide and 1.2–1.6 μm long). 16S rRNA gene sequence analysis indicated that strain AL46T belongs to the genus Acidocella, class Alphaproteobacteria. Strain AL46T was related most closely to the type strains of Acidocella facilis and Acidocella aminolytica (99.4 and 97.8 % 16S rRNA gene sequence similarity, respectively). Levels of DNA–DNA relatedness between strain AL46T and the above type strains were 40 %. The results of physiological and biochemical tests allowed the novel strain to be differentiated phenotypically from the two recognized Acidocella species. Data for predominant cellular fatty acids (cyclopropyl C19 : 0 and C18 : 1), major isoprenoid quinone (Q-10) and DNA G+C content (65.6 mol%) were in accordance with those reported for the genus Acidocella. Therefore, strain AL46T is considered to represent a novel species of the genus Acidocella, for which the name Acidocella aluminiidurans sp. nov. is proposed. The type strain is AL46T (=NBRC 104303T =VTCC-D9-1T).
Hikaru Akamine - One of the best experts on this subject based on the ideXlab platform.
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effect of nitrogen fertilizer application on growth biomass production and n uptake of torpedograss Panicum repens l
Weed Biology and Management, 2004Co-Authors: Mohammad Amzad Hossain, Yukio Ishimine, Hikaru Akamine, Hitoshi KuramochiAbstract:A glasshouse study was conducted to evaluate the effects of different rates (0, 50, 100, 200 and 400 kg ha−1) of nitrogen (N) fertilizer application on the growth, biomass production and N-uptake efficiency of torpedograss. The growth responses of torpedograss to the N application were significant throughout the observation periods. Torpedograss grown for 60 days obtained the highest total biomass of 23.0 g plant−1 with an application of 200 kg ha−1 N, followed by 20.4 g plant−1 with an application of 100 kg ha−1 N; when it was grown for 90 days a significantly higher biomass of 102.3–106.0 g plant−1 was obtained with the 200–400 kg ha−1 N than the biomass (68.0 g plant−1) obtained with the fertilizer applied at a lower rate. When the torpedograss was grown for 130 days the highest biomass was 230.0 g plant−1 with the 400 kg ha−1 N application, followed by a biomass of 150.0 g plant−1 with the 200 kg ha−1 N application, but the above-ground shoot in all treatments was over mature for animal food. The ratio of the above-ground shoot to the underground part increased with the increase in N application up to 400 kg ha−1 during the 90 days after planting (DAP), but the above-ground shoot biomass was the same with the 200 and 400 kg ha−1 N. The agronomic efficiency of the N application decreased to 5–38 with the increase in N application to 400 kg ha−1, which was less than half the agronomic efficiency with the 200 kg ha−1 N. The agronomic efficiency of N was very low (5–22) during the 60 DAP, which indicated that the N application would not be economically viable in this period for torpedograss as a pasture, and short-duration plants could be cultivated in torpedograss-infested fields to minimize weed-crop competition. The nitrogen concentration (%) in the torpedograss increased with the increase in N application, but N-uptake efficiency was the opposite and the value was very low with the 400 kg ha−1 N. The above results lead us to conclude that the N application rate of 200 kg ha−1 is the most effective for torpedograss growth.
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effect of standing water and shoot removal plus standing water regimes on growth regrowth and biomass production of torpedograss Panicum repens l
Weed Biology and Management, 2002Co-Authors: Mohammad Amzad Hossain, Yukio Ishimine, Hitoshi Kuramochi, Hikaru AkamineAbstract:The present study was undertaken from May 1996 to October 1997 in the glasshouse of the University of the Ryukyus, Okinawa, Japan to investigate standing water (12 cm deep) and shoot removal plus standing water regimes on morphological changes, growth, regrowth and biomass production of torpedograss (Panicum repens L.). The stem internode was longer in standing-water-treated plants than that in untreated plants. The root-crown was developed from the submerged stem-node. Spike-like tillers and sheath-like leaf blades were observed in water-treated plants. Higher shoot biomass and lower rhizome biomass were obtained in standing-water-treated plants than that in untreated plants. Standing-water-treated plants attained higher total biomass than untreated plants. Standing-water stress was the factor that inhibited regrowth of torpedograss when the above-ground shoot was removed. Rhizomes without shoots of 6-month-old torpedograss did not survive in standing water for more than 6 months. The results indicate that torpedograss can survive in standing water if the shoots remain above the water surface. Shoot removal is one effective way to control torpedograss regrowth in standing water. The results of this study may be dependent on season, day length, water temperature, water pH, water depth and salt concentration in water.
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interval between sequential applications of asulam for regrowth control of torpedograss Panicum repens l
Weed Biology and Management, 2002Co-Authors: Mohammad Amzad Hossain, Yukio Ishimine, Hitoshi Kuramochi, Hikaru AkamineAbstract:Two field experiments each conducted during a 1 year period at the Agricultural Experiment Farm, University of the Ryukyus, Japan evaluated the interval needed between sequential applications of asulam (3 kg ai ha−1) for successful control of torpedograss (Panicum repens L.). Regrowth of torpedograss from rhizomes was lowest when asulam was applied at 40-day intervals. Application at intervals of 70 days or longer completely controlled above-ground shoots but not regrowth from rhizomes. Above-ground biomass of torpedograss regrowth was 7- and 49-fold higher when asulam was applied at 70 and 100 day intervals, respectively, compared with 40-day intervals. Asulam applied three times at 40-day intervals starting 40 days after land preparation provided almost total torpedograss control 1 year after the initial application.
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influence of temperature levels and planting time on the sprouting of rhizome bud and biomass production of torpedograss Panicum repens l in okinawa island southern japan
Weed Biology and Management, 2001Co-Authors: Mohammad Amzad Hossain, Yukio Ishimine, Hikaru Akamine, Ichiro Nakamura, Hitoshi KuramochiAbstract:The present study describes the influence of temperature levels and planting time on the sprouting of rhizome-buds and the biomass production of torpedograss (Panicum repens L.) in the Okinawa prefecture, Japan. Torpedograss planted in each month (1994–95) was grown for 210 days. Sprouting of the rhizome-bud of torpedograss was 92–96% at the temperature range of 20–35°C in an incubator, and the sprouting was not observed at the extreme low and high temperature of ≤5 and ≥45°C, respectively. The plant showed 40–72% emergence when grown in pots throughout the year in the ambient temperature range of 17–29°C. The percentage emergence was comparatively higher in March to September, and shoots elongated rapidly in the period from April to October when the temperature range of 22–29°C prevailed. Torpedograss-rhizome sown in the period from January to June obtained significantly higher biomass because higher temperatures prevailed in the following growth period from May to October, as compared with the torpedograss-rhizome sown in the period of July to December. The plant required higher temperatures for proper growth and development during the period of moderate (70–110 days after planting (DAP)) and fast growth phases (110 DAP to the last harvest).
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application timing of asulam for torpedograss Panicum repens l control in sugarcane in okinawa island
Weed Biology and Management, 2001Co-Authors: Mohammad Amzad Hossain, Yukio Ishimine, Hitoshi Kuramochi, Hikaru AkamineAbstract:Field and glasshouse experiments were conducted from 1995 through 1996 to evaluate application timing of asulam (methyl sulfanilylcarbamate) for torpedograss (Panicum repens L.) control in relation to plant age in sugarcane. Above-ground shoots of torpedograss were completely controlled with asulam at 2–4 kg active ingredient (a.i.) ha−1 applied 60 or 80 days after planting (DAP) in artificially infested pots. But some newly developed rhizome buds survived after asulam application resulting in 1–25 and 76–100% or more regrowth in 60 and 80 DAP-applied pots, respectively. Whereas the herbicide at 2–4 kg a.i. ha−1 applied within 60 DAP completely controlled above-ground shoots, applied 80 DAP at 2 kg a.i. ha−1 it did not completely control the weed in the artificially infested field. Regrowth levels were 1–25 and 76–100% or more in 60 and 80 DAP-applied plots, respectively. Asulam at 2–3 kg a.i. ha−1 applied 20, 40, 60 or 80 DAP in a naturally infested field completely controlled above-ground shoots and regrowth levels were 76–100 or more, 51–75, 1–25 and 26–50% in these same DAP applied plots, respectively. The herbicide applied at 4 kg a.i. ha−1 caused chlorosis on younger sugarcane leaves (one-leaf stage), but when applied at 2–3 kg a.i. ha−1, no injury symptoms were shown. The herbicide at 2–4 kg a.i. ha−1 applied within 60 DAP resulted in remarkably higher yield and shoot biomass of sugarcane than that applied 80 DAP. This study suggested that asulam at 2–3 kg a.i. ha−1 should be applied 60 days after planting for the maximum control of torpedograss regrowth and better yield of sugarcane. This study also indicated that torpedograss cannot be completely controlled with a single application of asulam in a naturally infested field because of rhizome fragmentation by cross plowing and distribution of rhizomes into different soil layers that require different times to emerge. The shoots emerging after asulam application could not be controlled. Another study is required to determine the interval between sequential applications of asulam for better control of torpedograss in a naturally infested field.
Zeng-chin Liang - One of the best experts on this subject based on the ideXlab platform.
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Biological efficiency and nutritional value of the culinary-medicinal mushroom Auricularia cultivated on a sawdust basal substrate supplement with different proportions of grass plants
Elsevier, 2019Co-Authors: Chih-hung Liang, Yun-chen Kuo, Zeng-chin LiangAbstract:Auricularia polytricha was cultivated on a sawdust basal substrate supplemented with different proportions (30%, 45%, and 60%, respectively) of stalks of three grass plants, i.e., Panicum repens (PRS), Pennisetum purpureum (PPS), and Zea mays (ZMS), to determine the most effective substrate. The mycelial growth rate, total colonization time, days to primordial formation, biological efficiency and chemical composition of fruiting bodies were evaluated. The results indicated that 30PPS was the best substrate for mycelial growth of A. polytricha, with a corresponding total colonization period of 32.0 days. With the exception of 30PPS, the total biological efficiency of all of the substrates containing P. repens stalk, P. purpureum stalk and Z. mays stalk was higher (P
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biological efficiency and nutritional value of the culinary medicinal mushroom auricularia cultivated on a sawdust basal substrate supplement with different proportions of grass plants
Saudi Journal of Biological Sciences, 2016Co-Authors: Chih-hung Liang, Yun-chen Kuo, Zeng-chin LiangAbstract:Auricularia polytricha was cultivated on a sawdust basal substrate supplemented with different proportions (30%, 45%, and 60%, respectively) of stalks of three grass plants, i.e., Panicum repens (PRS), Pennisetum purpureum (PPS), and Zea mays (ZMS), to determine the most effective substrate. The mycelial growth rate, total colonization time, days to primordial formation, biological efficiency and chemical composition of fruiting bodies were evaluated. The results indicated that 30PPS was the best substrate for mycelial growth of A. polytricha, with a corresponding total colonization period of 32.0 days. With the exception of 30PPS, the total biological efficiency of all of the substrates containing P. repens stalk, P. purpureum stalk and Z. mays stalk was higher (P < 0.05) than that of the control. The most suitable substrate with a high biological efficiency was 60PRS (148.12%), followed by 30ZMS (145.05%), 45ZMS (144.15%) and 30PRS (136.68%). The nutrient values of fruiting bodies were affected by different substrates. The ash contents of A. polytricha cultivated on a substrate containing Z. mays stalk were higher than that of the control; meanwhile, the protein contents of mushroom cultivated on a substrate containing P. repens stalk (except substrate 45PRS) were higher than that of the control. The biological efficiency of the substrates was tested, and according to the results, it is feasible to use the stalks of P. repens and Z. mays on partially replaced sawdust to cultivate A. polytricha.
Yukio Ishimine - One of the best experts on this subject based on the ideXlab platform.
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effect of nitrogen fertilizer application on growth biomass production and n uptake of torpedograss Panicum repens l
Weed Biology and Management, 2004Co-Authors: Mohammad Amzad Hossain, Yukio Ishimine, Hikaru Akamine, Hitoshi KuramochiAbstract:A glasshouse study was conducted to evaluate the effects of different rates (0, 50, 100, 200 and 400 kg ha−1) of nitrogen (N) fertilizer application on the growth, biomass production and N-uptake efficiency of torpedograss. The growth responses of torpedograss to the N application were significant throughout the observation periods. Torpedograss grown for 60 days obtained the highest total biomass of 23.0 g plant−1 with an application of 200 kg ha−1 N, followed by 20.4 g plant−1 with an application of 100 kg ha−1 N; when it was grown for 90 days a significantly higher biomass of 102.3–106.0 g plant−1 was obtained with the 200–400 kg ha−1 N than the biomass (68.0 g plant−1) obtained with the fertilizer applied at a lower rate. When the torpedograss was grown for 130 days the highest biomass was 230.0 g plant−1 with the 400 kg ha−1 N application, followed by a biomass of 150.0 g plant−1 with the 200 kg ha−1 N application, but the above-ground shoot in all treatments was over mature for animal food. The ratio of the above-ground shoot to the underground part increased with the increase in N application up to 400 kg ha−1 during the 90 days after planting (DAP), but the above-ground shoot biomass was the same with the 200 and 400 kg ha−1 N. The agronomic efficiency of the N application decreased to 5–38 with the increase in N application to 400 kg ha−1, which was less than half the agronomic efficiency with the 200 kg ha−1 N. The agronomic efficiency of N was very low (5–22) during the 60 DAP, which indicated that the N application would not be economically viable in this period for torpedograss as a pasture, and short-duration plants could be cultivated in torpedograss-infested fields to minimize weed-crop competition. The nitrogen concentration (%) in the torpedograss increased with the increase in N application, but N-uptake efficiency was the opposite and the value was very low with the 400 kg ha−1 N. The above results lead us to conclude that the N application rate of 200 kg ha−1 is the most effective for torpedograss growth.
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effect of standing water and shoot removal plus standing water regimes on growth regrowth and biomass production of torpedograss Panicum repens l
Weed Biology and Management, 2002Co-Authors: Mohammad Amzad Hossain, Yukio Ishimine, Hitoshi Kuramochi, Hikaru AkamineAbstract:The present study was undertaken from May 1996 to October 1997 in the glasshouse of the University of the Ryukyus, Okinawa, Japan to investigate standing water (12 cm deep) and shoot removal plus standing water regimes on morphological changes, growth, regrowth and biomass production of torpedograss (Panicum repens L.). The stem internode was longer in standing-water-treated plants than that in untreated plants. The root-crown was developed from the submerged stem-node. Spike-like tillers and sheath-like leaf blades were observed in water-treated plants. Higher shoot biomass and lower rhizome biomass were obtained in standing-water-treated plants than that in untreated plants. Standing-water-treated plants attained higher total biomass than untreated plants. Standing-water stress was the factor that inhibited regrowth of torpedograss when the above-ground shoot was removed. Rhizomes without shoots of 6-month-old torpedograss did not survive in standing water for more than 6 months. The results indicate that torpedograss can survive in standing water if the shoots remain above the water surface. Shoot removal is one effective way to control torpedograss regrowth in standing water. The results of this study may be dependent on season, day length, water temperature, water pH, water depth and salt concentration in water.
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interval between sequential applications of asulam for regrowth control of torpedograss Panicum repens l
Weed Biology and Management, 2002Co-Authors: Mohammad Amzad Hossain, Yukio Ishimine, Hitoshi Kuramochi, Hikaru AkamineAbstract:Two field experiments each conducted during a 1 year period at the Agricultural Experiment Farm, University of the Ryukyus, Japan evaluated the interval needed between sequential applications of asulam (3 kg ai ha−1) for successful control of torpedograss (Panicum repens L.). Regrowth of torpedograss from rhizomes was lowest when asulam was applied at 40-day intervals. Application at intervals of 70 days or longer completely controlled above-ground shoots but not regrowth from rhizomes. Above-ground biomass of torpedograss regrowth was 7- and 49-fold higher when asulam was applied at 70 and 100 day intervals, respectively, compared with 40-day intervals. Asulam applied three times at 40-day intervals starting 40 days after land preparation provided almost total torpedograss control 1 year after the initial application.
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influence of temperature levels and planting time on the sprouting of rhizome bud and biomass production of torpedograss Panicum repens l in okinawa island southern japan
Weed Biology and Management, 2001Co-Authors: Mohammad Amzad Hossain, Yukio Ishimine, Hikaru Akamine, Ichiro Nakamura, Hitoshi KuramochiAbstract:The present study describes the influence of temperature levels and planting time on the sprouting of rhizome-buds and the biomass production of torpedograss (Panicum repens L.) in the Okinawa prefecture, Japan. Torpedograss planted in each month (1994–95) was grown for 210 days. Sprouting of the rhizome-bud of torpedograss was 92–96% at the temperature range of 20–35°C in an incubator, and the sprouting was not observed at the extreme low and high temperature of ≤5 and ≥45°C, respectively. The plant showed 40–72% emergence when grown in pots throughout the year in the ambient temperature range of 17–29°C. The percentage emergence was comparatively higher in March to September, and shoots elongated rapidly in the period from April to October when the temperature range of 22–29°C prevailed. Torpedograss-rhizome sown in the period from January to June obtained significantly higher biomass because higher temperatures prevailed in the following growth period from May to October, as compared with the torpedograss-rhizome sown in the period of July to December. The plant required higher temperatures for proper growth and development during the period of moderate (70–110 days after planting (DAP)) and fast growth phases (110 DAP to the last harvest).
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application timing of asulam for torpedograss Panicum repens l control in sugarcane in okinawa island
Weed Biology and Management, 2001Co-Authors: Mohammad Amzad Hossain, Yukio Ishimine, Hitoshi Kuramochi, Hikaru AkamineAbstract:Field and glasshouse experiments were conducted from 1995 through 1996 to evaluate application timing of asulam (methyl sulfanilylcarbamate) for torpedograss (Panicum repens L.) control in relation to plant age in sugarcane. Above-ground shoots of torpedograss were completely controlled with asulam at 2–4 kg active ingredient (a.i.) ha−1 applied 60 or 80 days after planting (DAP) in artificially infested pots. But some newly developed rhizome buds survived after asulam application resulting in 1–25 and 76–100% or more regrowth in 60 and 80 DAP-applied pots, respectively. Whereas the herbicide at 2–4 kg a.i. ha−1 applied within 60 DAP completely controlled above-ground shoots, applied 80 DAP at 2 kg a.i. ha−1 it did not completely control the weed in the artificially infested field. Regrowth levels were 1–25 and 76–100% or more in 60 and 80 DAP-applied plots, respectively. Asulam at 2–3 kg a.i. ha−1 applied 20, 40, 60 or 80 DAP in a naturally infested field completely controlled above-ground shoots and regrowth levels were 76–100 or more, 51–75, 1–25 and 26–50% in these same DAP applied plots, respectively. The herbicide applied at 4 kg a.i. ha−1 caused chlorosis on younger sugarcane leaves (one-leaf stage), but when applied at 2–3 kg a.i. ha−1, no injury symptoms were shown. The herbicide at 2–4 kg a.i. ha−1 applied within 60 DAP resulted in remarkably higher yield and shoot biomass of sugarcane than that applied 80 DAP. This study suggested that asulam at 2–3 kg a.i. ha−1 should be applied 60 days after planting for the maximum control of torpedograss regrowth and better yield of sugarcane. This study also indicated that torpedograss cannot be completely controlled with a single application of asulam in a naturally infested field because of rhizome fragmentation by cross plowing and distribution of rhizomes into different soil layers that require different times to emerge. The shoots emerging after asulam application could not be controlled. Another study is required to determine the interval between sequential applications of asulam for better control of torpedograss in a naturally infested field.
Hitoshi Kuramochi - One of the best experts on this subject based on the ideXlab platform.
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effect of nitrogen fertilizer application on growth biomass production and n uptake of torpedograss Panicum repens l
Weed Biology and Management, 2004Co-Authors: Mohammad Amzad Hossain, Yukio Ishimine, Hikaru Akamine, Hitoshi KuramochiAbstract:A glasshouse study was conducted to evaluate the effects of different rates (0, 50, 100, 200 and 400 kg ha−1) of nitrogen (N) fertilizer application on the growth, biomass production and N-uptake efficiency of torpedograss. The growth responses of torpedograss to the N application were significant throughout the observation periods. Torpedograss grown for 60 days obtained the highest total biomass of 23.0 g plant−1 with an application of 200 kg ha−1 N, followed by 20.4 g plant−1 with an application of 100 kg ha−1 N; when it was grown for 90 days a significantly higher biomass of 102.3–106.0 g plant−1 was obtained with the 200–400 kg ha−1 N than the biomass (68.0 g plant−1) obtained with the fertilizer applied at a lower rate. When the torpedograss was grown for 130 days the highest biomass was 230.0 g plant−1 with the 400 kg ha−1 N application, followed by a biomass of 150.0 g plant−1 with the 200 kg ha−1 N application, but the above-ground shoot in all treatments was over mature for animal food. The ratio of the above-ground shoot to the underground part increased with the increase in N application up to 400 kg ha−1 during the 90 days after planting (DAP), but the above-ground shoot biomass was the same with the 200 and 400 kg ha−1 N. The agronomic efficiency of the N application decreased to 5–38 with the increase in N application to 400 kg ha−1, which was less than half the agronomic efficiency with the 200 kg ha−1 N. The agronomic efficiency of N was very low (5–22) during the 60 DAP, which indicated that the N application would not be economically viable in this period for torpedograss as a pasture, and short-duration plants could be cultivated in torpedograss-infested fields to minimize weed-crop competition. The nitrogen concentration (%) in the torpedograss increased with the increase in N application, but N-uptake efficiency was the opposite and the value was very low with the 400 kg ha−1 N. The above results lead us to conclude that the N application rate of 200 kg ha−1 is the most effective for torpedograss growth.
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effect of standing water and shoot removal plus standing water regimes on growth regrowth and biomass production of torpedograss Panicum repens l
Weed Biology and Management, 2002Co-Authors: Mohammad Amzad Hossain, Yukio Ishimine, Hitoshi Kuramochi, Hikaru AkamineAbstract:The present study was undertaken from May 1996 to October 1997 in the glasshouse of the University of the Ryukyus, Okinawa, Japan to investigate standing water (12 cm deep) and shoot removal plus standing water regimes on morphological changes, growth, regrowth and biomass production of torpedograss (Panicum repens L.). The stem internode was longer in standing-water-treated plants than that in untreated plants. The root-crown was developed from the submerged stem-node. Spike-like tillers and sheath-like leaf blades were observed in water-treated plants. Higher shoot biomass and lower rhizome biomass were obtained in standing-water-treated plants than that in untreated plants. Standing-water-treated plants attained higher total biomass than untreated plants. Standing-water stress was the factor that inhibited regrowth of torpedograss when the above-ground shoot was removed. Rhizomes without shoots of 6-month-old torpedograss did not survive in standing water for more than 6 months. The results indicate that torpedograss can survive in standing water if the shoots remain above the water surface. Shoot removal is one effective way to control torpedograss regrowth in standing water. The results of this study may be dependent on season, day length, water temperature, water pH, water depth and salt concentration in water.
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interval between sequential applications of asulam for regrowth control of torpedograss Panicum repens l
Weed Biology and Management, 2002Co-Authors: Mohammad Amzad Hossain, Yukio Ishimine, Hitoshi Kuramochi, Hikaru AkamineAbstract:Two field experiments each conducted during a 1 year period at the Agricultural Experiment Farm, University of the Ryukyus, Japan evaluated the interval needed between sequential applications of asulam (3 kg ai ha−1) for successful control of torpedograss (Panicum repens L.). Regrowth of torpedograss from rhizomes was lowest when asulam was applied at 40-day intervals. Application at intervals of 70 days or longer completely controlled above-ground shoots but not regrowth from rhizomes. Above-ground biomass of torpedograss regrowth was 7- and 49-fold higher when asulam was applied at 70 and 100 day intervals, respectively, compared with 40-day intervals. Asulam applied three times at 40-day intervals starting 40 days after land preparation provided almost total torpedograss control 1 year after the initial application.
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influence of temperature levels and planting time on the sprouting of rhizome bud and biomass production of torpedograss Panicum repens l in okinawa island southern japan
Weed Biology and Management, 2001Co-Authors: Mohammad Amzad Hossain, Yukio Ishimine, Hikaru Akamine, Ichiro Nakamura, Hitoshi KuramochiAbstract:The present study describes the influence of temperature levels and planting time on the sprouting of rhizome-buds and the biomass production of torpedograss (Panicum repens L.) in the Okinawa prefecture, Japan. Torpedograss planted in each month (1994–95) was grown for 210 days. Sprouting of the rhizome-bud of torpedograss was 92–96% at the temperature range of 20–35°C in an incubator, and the sprouting was not observed at the extreme low and high temperature of ≤5 and ≥45°C, respectively. The plant showed 40–72% emergence when grown in pots throughout the year in the ambient temperature range of 17–29°C. The percentage emergence was comparatively higher in March to September, and shoots elongated rapidly in the period from April to October when the temperature range of 22–29°C prevailed. Torpedograss-rhizome sown in the period from January to June obtained significantly higher biomass because higher temperatures prevailed in the following growth period from May to October, as compared with the torpedograss-rhizome sown in the period of July to December. The plant required higher temperatures for proper growth and development during the period of moderate (70–110 days after planting (DAP)) and fast growth phases (110 DAP to the last harvest).
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application timing of asulam for torpedograss Panicum repens l control in sugarcane in okinawa island
Weed Biology and Management, 2001Co-Authors: Mohammad Amzad Hossain, Yukio Ishimine, Hitoshi Kuramochi, Hikaru AkamineAbstract:Field and glasshouse experiments were conducted from 1995 through 1996 to evaluate application timing of asulam (methyl sulfanilylcarbamate) for torpedograss (Panicum repens L.) control in relation to plant age in sugarcane. Above-ground shoots of torpedograss were completely controlled with asulam at 2–4 kg active ingredient (a.i.) ha−1 applied 60 or 80 days after planting (DAP) in artificially infested pots. But some newly developed rhizome buds survived after asulam application resulting in 1–25 and 76–100% or more regrowth in 60 and 80 DAP-applied pots, respectively. Whereas the herbicide at 2–4 kg a.i. ha−1 applied within 60 DAP completely controlled above-ground shoots, applied 80 DAP at 2 kg a.i. ha−1 it did not completely control the weed in the artificially infested field. Regrowth levels were 1–25 and 76–100% or more in 60 and 80 DAP-applied plots, respectively. Asulam at 2–3 kg a.i. ha−1 applied 20, 40, 60 or 80 DAP in a naturally infested field completely controlled above-ground shoots and regrowth levels were 76–100 or more, 51–75, 1–25 and 26–50% in these same DAP applied plots, respectively. The herbicide applied at 4 kg a.i. ha−1 caused chlorosis on younger sugarcane leaves (one-leaf stage), but when applied at 2–3 kg a.i. ha−1, no injury symptoms were shown. The herbicide at 2–4 kg a.i. ha−1 applied within 60 DAP resulted in remarkably higher yield and shoot biomass of sugarcane than that applied 80 DAP. This study suggested that asulam at 2–3 kg a.i. ha−1 should be applied 60 days after planting for the maximum control of torpedograss regrowth and better yield of sugarcane. This study also indicated that torpedograss cannot be completely controlled with a single application of asulam in a naturally infested field because of rhizome fragmentation by cross plowing and distribution of rhizomes into different soil layers that require different times to emerge. The shoots emerging after asulam application could not be controlled. Another study is required to determine the interval between sequential applications of asulam for better control of torpedograss in a naturally infested field.
