Journal of Weed Science and Technology
Online ISSN : 1882-4757
Print ISSN : 0372-798X
ISSN-L : 0372-798X
Volume 25, Issue 3
Displaying 1-11 of 11 articles from this issue
  • Outline of Study and Its Problems after World War II
    Takeo TANIMOTO
    1980 Volume 25 Issue 3 Pages 165-172
    Published: October 25, 1980
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
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  • III. Herbicidal Activity of 1-Alkyl-3-(substituted phenyl) dihydrouracils and the Other Amino Acid Derivatives
    Mitsuyoshi OKII, Masayuki TERANISHI, Ikuo MATSUKUMA, Makoto KONNAI, Te ...
    1980 Volume 25 Issue 3 Pages 173-178
    Published: October 25, 1980
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
    1-Alkyl-3-(substituted phenyl) dihydrouracils [1-alkyl-3-(4-chlorophenyl) dihydrouracils (ACDU) and 1-methyl-3-(substituted phenyl) dihydrouracils (MSDU)] which were the ring closure compounds of N-alkyl-N-(substituted phenylcarbamoyl), β-alanines and other related amino acid derivatives were examined on their herbicidal activity by pot tests. Activity of the optical isomers of amino acid residues of the compounds was also evaluated. Results obtained were as follows:
    (1) In general, activity of ACDU was higher than that of the compounds before ring closure, and these results were consistent with the higher values of the hydrophobicity (log P) of the both compounds. The alkyl moiety with the highest activity among ACDU was iso-propyl group.
    (2) Activity of MSDU decreased in the following order: -H≥4-Br≥3-Cl≥3, 4-diCl compounds. But, from the standpoint of a margin of selectivity between wheat and broad-leaved plants, 3, 4-dichlorocompound (DCMD) was the most excellent.
    (3) Activity of 3-(3, 4-dichlorophenyl) hydantoin derivatives, N-(N′-methoxymethyl-N′-substituted phenylcarbamoyl) amino acids and substituted benzothiazole derivatives (urea, hydantoin and dihydrouracil types) were generally low.
    (4) Within the limits of this experiments (16 compounds), activity of the optical isomers of the amino acid residues of the compounds was higher usually in the following order: D->DL->L- isomers.
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  • IV. Herbicidal Properties of 3-(3, 4-Dichlorophenyl)-1-methyl dihydrouracil (DCMD)
    Mitsuyoshi OKII, Masayuki TERANISHI, Ikuo MATSUKUMA, Makoto KONNAI, Te ...
    1980 Volume 25 Issue 3 Pages 179-184
    Published: October 25, 1980
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
    During the course of our investigation to discover new herbicides among amino acid related compounds, we have found that N-(3, 4-dichlorophenylcarbamoyl)-N-methyl β-alanine methyl ester (MCMD) and 3-(3, 4-dichlorophenyl)-1-methyl dihydrouracil (DCMD) showed relatively strong post-emergence herbicidal activity against broadleaf plants but did not showed any injury to wheat. In the present paper, post-emergence activity of DCMD was compared with that of MCMD, and it was found that DCMD had a higher selectivity between broadleaf weeds and wheat than MCMD. Herbicidal properties of DCMD examined were as follows:
    (1) As a result of foliar application, gramineous plants, Galium spurium L., Artemisia vulgaris L. and Rumex acetosella L. were resistant. Erigeron philadelphicus L., Hemistepta lyrata Bunge, Cardamine flexuosa With. and Veronica arvensis L., which are winter annual weeds, were susceptible.
    (2) From a result of soil treatment, injury of wheat was not observed even at higher dosage (80g/a). In the Petri dish test, susceptible difference between wheat and radish at germinating stage was not recognized.
    (3) The persistence (half life period) in the upland soil (black volcanic ash soil) was about 1/3 period compared with that of diuron. Compared with the downward movement of diuron (1cm) in the upland soil, that of DCMD (above 4cm) was considerably large.
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  • Hiroshi MATSUMOTO, Kozo ISHIZUKA
    1980 Volume 25 Issue 3 Pages 185-193
    Published: October 25, 1980
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
    The selectivity pattern of foliar-applied simetryne [2, 4-bis (ethylamino)-6-(methylthio)-s-triazine] was studied in six gramineous plant species. Their tolerance to simetryne could be described by the following sequence: rice (Oryza sativa L.)> wheat (Triticum aestivum L.)>corn (Zea mays L.)>barnyardgrass (Echinochloa crus-galli Beauv.)>large crabgrass (Digitaria adscendens Henr.)>finger millet (Eleusine coracana Gaertn.). In order to clarify the selectivity mechanism of simetryne, its absorption, translocation and metabolism in rice (tolerant) and barnyardgrass (susceptible) were investigated. The rates of absorption of 14C-simetryne by shoots were much higher in barnyardgrass than in rice, but few differences were observed in translocation and degradation rates. The main metabolic pathway, however, was remarkably different. The investigation on absorption of 14C-simetryne was then further extended to six gramineous plant species. The rates of absorption were remarkably different among these plants, susceptible plants exhibiting much higher rates than tolerant species. It was concluded that the selectivity of foliar-applied simetryne was mainly due to species related differences in the rates of absorption, and in metabolic pathways.
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  • I. Competition between Upland Crops and Weeds
    Iwaho IWATA, Shigeru TAKAYANAGI
    1980 Volume 25 Issue 3 Pages 194-199
    Published: October 25, 1980
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
    From 1968 to '70, we have carried out experiments to clarify degree and pattern of the damage to upland crops due to the competition with weeds under non-weeding condition.
    The results are summarized as follows:
    1. Growth of weed was more influenced by the weight of large crabgrass and goosegrass than kinds of crops and its planting density.
    2. Number of emergence of weeds was affected remarkably by kinds of crops, but the total number of weeds was decresed in late stage.
    3. Patterns of weed damage to each crop-plants are as follows. Growth of sorghum was not affected by weeds, and this crop suppressed the growth of weeds very strongly.
    Growth of upland rice and peanut was affected by weeds from middle stage.
    In soybean (summer soybean) the ratio of crop weight to total community weight was largely reduced at late stage, caused by the defoliation before havesting time.
    Corn showed the habitat segregation and it grew normaly together with weeds in the same field.
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  • II. The Effects of Weed Competition on the Growth and Yield of Crops
    Iwaho IWATA, Shigeru TAKAYANAGI
    1980 Volume 25 Issue 3 Pages 200-206
    Published: October 25, 1980
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
    In upland rice, peanut, corn and soybean field, non-weeding, once-weeding and twice-weeding treatments were done, for the purpose to know the effects of weed competition on the growth and yield of crops.
    1) The composition of weed community was changed after weeding, namely, in weeding plot smaller broadleaf weeds, umbrella sedge and later emerging gramineous weeds grew much than non-weeding plot. But the aspect of this change was differented between wide spacing and dense spacing of crops.
    2) Effect on growth of crops by weed competitive stress was appeared as decreasing stem or branch number of upland rice, peanut and soybean, and also plant height of corn.
    Yield decrease of crop was resulted from the poor ripening more than decreasing of panicle or pod number.
    3) Degree of damage to crops due to weeds can be estimated by measuering the ratio of crop weight to total community weight at 50 days or later after sowing.
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  • III. Competition between Crops and Weeds on Absorption of Nitrogen
    Iwaho IWATA, Shigeru TAKAYANAGI
    1980 Volume 25 Issue 3 Pages 207-211
    Published: October 25, 1980
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
    In this paper the competition between crops and weeds on absorption of nitrogen was reported.
    1) Nitrogen content (%) per dry matter weights decreased with the growing process of crops. It was the least in corn, medium in upland rice, and the largest in soybean and peanut.
    2) Effect of weeding on seasonal change of nitrogen content (%) was largely under wide spacing in upland rice and corn, only a little on both spacing in soybean and peanut.
    3) Competition between crops and weeds on nitrogen absorption was appeared seriously at early stage in corn, and nitrogen content was decreased earliar than weight of dry matter. In legminous crops its competition was not serious, but in upland rice it was serious at middle stage of growth.
    4) Nitrogen content (%) in each kind of weed was differed a little on each croping fields.
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  • Keitaro IKAI, Shizuo NISHI
    1980 Volume 25 Issue 3 Pages 212-214
    Published: October 25, 1980
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
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  • Mamoru NASHIKI, Tatsuro NOMOTO, Norikazu HARASHIMA
    1980 Volume 25 Issue 3 Pages 214-216
    Published: October 25, 1980
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
    Download PDF (318K)
  • 1980 Volume 25 Issue 3 Pages 217-231
    Published: October 25, 1980
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
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  • Nobumasa ICHIZEN, Hideo CHISAKA, Kazuyuki ITOH, Kiyoshi KOJIMA, Katsuy ...
    1980 Volume 25 Issue 3 Pages 232-238
    Published: October 25, 1980
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
    Download PDF (1097K)
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