Journal of Weed Science and Technology
Online ISSN : 1882-4757
Print ISSN : 0372-798X
ISSN-L : 0372-798X
Volume 28, Issue 1
Displaying 1-10 of 10 articles from this issue
  • Masuji MIYAHARA
    1983 Volume 28 Issue 1 Pages 1-11
    Published: May 25, 1983
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
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  • I. Variability among Strains in Ecological and Morphological Characteristics
    Masanao YONEKURA
    1983 Volume 28 Issue 1 Pages 12-24
    Published: May 25, 1983
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
    Twenty strains of Cyperus serntinus Rottb., a perennial paddy weed, were collected from 18 locations in Kanagawa Prefecture and were grown in pots for 2-3 years until 1975.
    In the first study in 1976, 7 characters of each clone in relation to tuber emergence time, heading time, and shape and leaf growth were surveyed under the same growing conditions in order to analyze the variations within clones grown in a limited area (same paddy field or same waterway side) of the 18 locations.
    In the second study in 1977, the following 20 characters of 20 strains from 18 locations were evaluated under the same growing conditions in order to identify variations among the strains, tuber emergence time, heading time, stalk length and diameter, leaf length and width, numer of stalks, dry leaf and stalk weight, spike and spikelet length, number of spikelets and seeds per spike, 1, 000-seed weight, tuber length and diameter, fresh tuber weight, ratio of length to diameter of tuber, number of tubers per clone, fresh tuber weight per clone and number of tuber nodes.
    Results are as follows.
    (1) In the first study, significant differences were recognized among the clones in each of the 7 locations, while no difference was found in the other 11 locations.
    (2) In the second study, statistical analysis showed significant differences in twenty characters among twenty strains at 1 per cent level.
    (3) Of all the correlations between the twenty characters observed, high correlation coefficient of over 0.80 was obtained in thirteen combinations. Particularly, there was a close correlation between the characteristics of vegetative and reproductive organs.
    (4) Based on the principal component analysis, the scatter diagram of twenty strains on the axes of the first, second and third principal components suggested that all the strains could be classified into 7 groups.
    (5) The existence of such intraspecific variations in this species in a similar climatic area would suggest the importance of investigations on their relation to weed control in order to improve the control measures.
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  • 2. Morphological Characters and Growth Habit
    Mitsuyoshi OKUMA, Syoji CHIKURA, Junichi YOSHIDOME
    1983 Volume 28 Issue 1 Pages 25-30
    Published: May 25, 1983
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
    1. Morphological characters and growth habit of a subspecies of P. distichum L. “Chikugo-suzumenohie” were investigated and compared with those of the common variety P. distichum L. “Kishu-suzumenohie”
    2. Morphological characters of “Chikugo-suzumenohie” were more suited to the creek environment and the plant grew more vigorously than “Kishu-suzumenohie”. The whole surface of the creeks where overwintering stems were planted on the border was covered with the plants within two or three years.
    3. The higher the concentration of NH4-N in water, the more vigorously both species grew. The effect of concentration in the case of P2O5 was less evident than in the case of NH4-N.
    4. Adaptability of “Chikugo-suzumenohie” to the pH of water and soil moisture was lower than that of “Kishu-suzumenohie”.
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  • 3. Ecological Investigation on Sprouting of Stems
    Mitsuyoshi OKUMA, Shoji CHIKURA, Yoshikazu MORIYAMA
    1983 Volume 28 Issue 1 Pages 31-34
    Published: May 25, 1983
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
    1. Sprouting of stems of a subspecies of Paspalum distichum L. “Chikugo-suzumenohie” growing in creeks was investigated in both the overwintering and growing stems.
    2. Maximum, optimum and minimum temperatures were 40°C, 35-35°C and 10°C, respectively.
    3. All the nodes of the stems except a few terminal nodes showed high sprouting ability.
    4. Under the upland field conditions, excised overwintering stems showed the highest rate of sprouting. However, under puddled soil conditions sprouting was absent.
    5. Judging from the seasonal changes in the sprouting rate of stems, it appears that the optimum period of control of this wede should extend from the end of May to the middle of June.
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  • Keizo IWASAKI, Kumetaro IDENO, Hiroshi HAGIMOTO
    1983 Volume 28 Issue 1 Pages 35-42
    Published: May 25, 1983
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
    Twentyfive strains of a noxious weed growing in Japanese paddy fields, Scirpus juncoides Roxb. var. ohwianus T. Koyama, were collected from different locations from Hakkaido to Kyushu and were compared morphologically. The effect of chlornitrofen on these weeds was also evaluated.
    1. Maximum and minimum tiller number was determined in strains collected in Shimane Prefecture and Hokkaido, respectively. The stem number of the Shimane and Hokkaido strains was 132 and 32 respectively 70 days after transplanting of a hill composed of 3 stems of which height was cut to 5cm. (Table 2)
    2. The tillering patterns were classified into three groups according to the period of active tillering in each strain, which in 4, 19 and 2 strains took place within 7 weeks after transplanting, 7 to 10 weeks after transplanting and throughout the growing period, respectively. (Fig. 1)
    3. The notrhern strains showed earlier heading than the southern strains. The heading of the three strains of Hokkaido began within 3 weeks after transplanting whereas that of the others trains began 4 to 10 weeks after transplanting. (Table 2, Fig. 2)
    4. The ratios of bract to stem length were nearly constant (ratio; 0.30-0.40) in all the strains except for those of Hokkaido (ratio; 0.19-0.21) and Shimane Prefecture (ratio; 0.51). The bract length of the strains of Hokkaido was less than that of the other strains and the stem of the strain of Shimane was rather short. (Table 3)
    5. The thousand-kernel-weight of the strains of Hokkaido was higher than that of the other strains. (Table 3)
    6. There was a high positive correlation between the seed weight and length of spikelet.
    7. The effect of granules of chlornitrofen applied before emergence at the rate of 3.6kg (a. i.)/ha on the 25 strains of S. juncoides var. ohwianus varied with the strains but was comparatively low in all the strains. No correlation between seed weight and the effect of chlornitrofen could be recognized. (Table 5)
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  • Katsuichiro KOBAYASHI, Katsunori ICHINOSE, Hiroshi HYAKUTAKE, Kozo ISH ...
    1983 Volume 28 Issue 1 Pages 43-50
    Published: May 25, 1983
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
    Effects of naproanilide [1-(2-naphthoxy) propionanilide] treatment at different growth stages on tuberization and RNA synthesis of C. serotinus Rottb. was studied in relation to its effect on growth.
    The inhibition of tuberization concomitant with the stimulation of hill production and rhizome abnormality were induced regardless of age when treated. The inhibitory and formative effects on the growth of shoot or root were observed in the early stage, but these effects diminished as the growth stage of the treated plant advanced. With treatment during tuberization, tuber initiation was inhibited while neither the enlargement nor the tuber sprouting activity were affected.
    RNA synthesis in rhizome, expressed by uracil incorporation into RNA, was stimulated more remarkably than in the other organs by treatment at any given growth stage.
    The results suggested that naproanilide inhibited tuber initiation through its action on the RNA synthetic process related to the development of rhizome into tuber.
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  • Harumi SEKO, Tadashi SAMURA, Hirotsugu KOSHIO
    1983 Volume 28 Issue 1 Pages 51-53
    Published: May 25, 1983
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
    Application of herbicides to rice seedling cases was tested, using commercial granules of pyrazolate 10% and chlomethoxynil 7%. The application to rice seedling cases at the rate of 150g/case before transplanting was compared with the soil treatment at the rate of 300g/a at 3 days after transplanting in paddy fields. The application of each herbicide to rice seedling cases was less effective against weeds than the soil treatment. But rice did not become injured, and there was a small increase in the number of tillers.
    As a whole, this application is suitable for practical use, although some improvement in the process of granule formulation would be desirable with regard to water solubility and spread. This method could be effective in saving labor herbicide applications in rice fields.
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  • Akihiro KATO, Yoshiji OKUDA
    1983 Volume 28 Issue 1 Pages 54-56
    Published: May 25, 1983
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
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  • Kunikazu UEKI, Soichi NAKAYAMA, Hiroshi MATSUMOTO, Katsuichiro KOBAYAS ...
    1983 Volume 28 Issue 1 Pages 57-64
    Published: May 25, 1983
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
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  • 1983 Volume 28 Issue 1 Pages 65-68
    Published: May 25, 1983
    Released on J-STAGE: December 17, 2009
    JOURNAL FREE ACCESS
    Download PDF (606K)
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