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Volume 33 (1988)
- Issue 4 Pages 223-
- Issue 3 Pages 161-
- Issue 2 Pages 77-
- Issue 1 Pages 1-
- Issue Suppl Pages 1-
Volume 33, Issue 1
Displaying 1-8 of 8 articles from this issue
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I. Cutting at Different Maturing Stages and Different Heights with Respect to Transplanted Plants.Akio HONGO1988 Volume 33 Issue 1 Pages 1-7
Published: May 26, 1988
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSField experiments were conducted at Obihiro in Hokkaido in 1982 and 1984 to study the effects of cutting at different maturing stages and different heights on growth response and seed production in R. obtusifolius and R. crispus. Roots of both species were collected in early May and transplanted into the experimental site.
1. R. crispus plants flowered 7-10 days earlier than R. obtusifolius.
2. The reproductive effort was significantly higher in R. crispus, while the reverse result was obtained in terms of proportion of root.
3. Seed production of both species was the least when aerial parts were cut at the beginning of seed ripening in 1982 and 1984. R. obtusifolius produced some seed, whereas R. crispus very few at regrowth after cutting at this stage.
4. R. crispus produced some seeds when cut at higher than 10cm in height, however, it produced few when cut at lower than 5cm. In contrast, R. obtusifolius produced some seeds regardless of the height at which it was cut.View full abstractDownload PDF (699K) -
II. Cutting at Different Maturing Stages with respect to Plants Established from Seeds.Akio HONGO1988 Volume 33 Issue 1 Pages 8-13
Published: May 26, 1988
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSThe growth response and seed production were compared between R. obtusifolius and R. crispus after cutting at different maturing stages at Obihiro in Hokkaido during 1984 to 1986. Seeds were sown in the field on 14 June 1984. Different cutting regimes were carried out during the second and third seasons.
1. R. obtusifolius developed more inflorescences but was lower in height than R. crispus. Both species produced almost the same DM and seeds on an average of all cutting treatments.
2. R. crispus produced viable seeds about one week earlier than R. obtusifolius during undisturbed growth in both seasons. The requirement for total accumulated temperatures above 5°C base was 10-12% higher in R. obtusifolius than in R. crispus.
3. Viable seed productions of both species decreased sharply when aerial parts were cut at the beginning of seed ripening in early July.
4. Both species produced more than 8, 000 viable seeds at regrowth in the first 3 cuttings (from elongation of flower stalk to flowering). However, viable seed production at regrowth was significantly higher in R. obtusifolius than in R. crispus after cutting 4 (beginning of seed ripening).
5. Both species showed the similar distribution of root DM in the 0-20cm horizon in soil. However, root DM weight was significantly greater in R. obtusifolius than in R. crispus in the 20-50cm horizon.View full abstractDownload PDF (634K) -
8. Effects of Nitrogen Fertilizer Application on Growth and Seed Production of Rottboellia exaltata L.f. and Solanum alatum MOENCHYukio ISHIMINE, Seiichi MURAYAMA, Sigeo MATSUMOTO1988 Volume 33 Issue 1 Pages 14-22
Published: May 26, 1988
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSThe effect of nitrogen fertilization on growth and seed production was evaluated for Rottboellia exaltata L. f., and Solanum alatum MOENCH., at 0, 10, 20 and 40kg/10a. The results are summarized as follows:
1. In Rottboellia the plant height decreased as the amount of nitrogen application was increased. The value was largest in the N-0 treatment at 90 days after seeding. In Solanum the plant lenght increased with increasing nitrogen application reaching a maximum in the N-40 treatment at 100 days after seeding (Fig. 1).
2. In Rottboellia the total dry weight started increasing rapidly at 30 days after seeding but the increase became less at 90 days after seeding. The value was largest in the N-20 treatment at 120 days after seeding. In Solanum the total dry weight started increasing rapidly at 60 days after seeding and then started decreasing at 90 days after seeding. The maximum value was reached in the N-20 treatment at 90 days after seeding (Fig. 2).
3. In both Rottboellia and Solanum, the dry weight percentage allocation of spike, fruit and flower increased at higher nitrogen levels, while the dry weight percentage allocation of root, stem and leaf decreased as the amount of nitrogen application was increased (Fig. 3).
4. In Rottboellia the leaf area increased with increasing nitrogen application reaching a maximum in the N-20 treatment at 120 days after seeding. In Solanum the leaf area reached a maximum in the N-40 treatment at 90 days after seeding and then decreased at a fast rate (Fig. 4).
5. In Rottboellia heading was delayed slightly in the N-40 treatment and in Solanum flowering was delayed significantly in the N-40 treatment. In both Rottboellia and Solanum the values of spike, fruit and flower were largest in the N-20 treatment (Table 1).View full abstractDownload PDF (1021K) -
I. Seed Dormancy, Germination, and Seedling EmergenceMuhamad Ahmad CHOZIN, Kyojiro NAKAGAWA1988 Volume 33 Issue 1 Pages 23-30
Published: May 26, 1988
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSThe autecology of Cyperus iria L., a principal weed in paddy fields through the world, and a morphologically similar species, C. microiria STEUD., a serious weed in upland fields in Japan, was investigated in an effort to establish effective measures of control. First-run experiments were carried out on seed dormancy, germination, and seedling emergence. The results are summarized as follows:
1) Forty percent of fresh seeds of C. iria germinated, and in only a short period of after-ripening most of the dormant seeds could germinate; C. microiria seeds are dormant, and dormancy could be broken by burying the seeds in upland soil or by storing them at 15°C in a wet condition (Figs, 1, 3).
2) Storage in the darkness at low temperature or in submerged soil caused the seeds of both species to enter into secondary dormancy. Moreover, it was considered that keeping C. microiria seeds in a wet or submerged condition at 25 and 35°C also caused them to enter into secondary dormancy (Figs. 1, 3).
3) Both species seeds required light for germination. However, in the darkness under an alternating temperature (20/35°C) their germination could be stimulated by burying them in upland soil: the longer buried, the more seeds germinated (Fig. 2).
4) There is a difference in the temperature requirement for seed germination between C. iria and C. microiria. Seeds of C. microiria germinated at 25 to 45°C whereas those of C. iria at a wider range of temperature, 15 to 40°C. However, the highest germination percentages of the two species were found at 20/30°C alternating temperature (Table 1).
5) Seeds of both germinated well at the soil surface, but at about one centimeter below the surface, few C. iria seedlings emerged and C. microiria not at all (Table 2).View full abstractDownload PDF (878K) -
Mamoru NASHIKI, Tatsuro NOMOTO, Ryohei MEGURO1988 Volume 33 Issue 1 Pages 31-40
Published: May 26, 1988
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSIn order to prevent D. ciliaris infestation into a sward, the effect of fertilizer application and cutting on the growth of D. ciliaris was evaluated.
The results obtained are as follows.
1. During the period with high air temperature from July to August, D. ciliaris showed a remarkable increase in plant height, in contrast to other grasses such as orchardgrass and tall fescue (Fig. 2).
2. In a sward in which the area of bare ground was kept minimum by the application of low levels of fertilizer in the summer and cutting performed at 8 week intervals from July through October, D. ciliaris infestation was inhibited, a high yield of grass was obtained and a high population density of grasses was maintained. There was a negative correlation between the annual yield of D. ciliaris and both the annual grass yield and maintenance rate of grasses including five species such as orchardgrass, perennial ryegrass, tall fescue, redtop and Kentucky bluegrass.
3. Infestation of D. ciliaris into a sward resulted in the decrease of the total production of grasses after July, and intensified the seasonal trend of decreased production of grasses in summer and autumn (Fig. 4). Though the digestibility of D. ciliaris in July and August was superior to that of orchardgrass and tall fescue, it was lower in September and October. The number of calories and content of crude protein of D. ciliaris in July and October showed low values compared with the corresponding values for the grasses (Table 4).
4. Discontinuation of cutting during on 8 week period after early July, seemed to be on effective means to prevent D. ciliaris infestation into the sward (Table 5).View full abstractDownload PDF (1120K) -
Kozo ISHIZUKA, Hiroshi MATSUMOTO, Hiroshi HYAKUTAKE1988 Volume 33 Issue 1 Pages 41-48
Published: May 26, 1988
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSEffect of light on the mode of action of diphenyl ether herbicide chlomethoxynil (2, 4-dichloropheny 1-3′-methoxy-4′-nitrophenyl ether) was investigated in rice (Oryza sativa L.) and barnyardgrass (Echinochloa oryzicola VASING.). The herbicide showed phytotoxic activity on barnyardgrass in the light, but not in the dark. Rice plant showed no phytotoxic symptoms either in light or dark.
Barnyardgrass absorbed the herbicide from shoots much faster than rice, however, a little difference in rate was observed between the light and dark in the two plants. Metabolic activity of the herbicide was much greater in rice, especially in the light, compared with only slight changes in barnyardgrass. Metabolic activity and absorption by shoots were considered factors of the selective action of the herbicide. It was found that light increased the herbicidal detoxifying activity in rice plant.View full abstractDownload PDF (2729K) -
Kazuyuki ITOH, Masuji MIYAHARA1988 Volume 33 Issue 1 Pages 49-54
Published: May 26, 1988
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSThe damage caused by the Sagittaria trifolia L. used to rice cultivated under ordinary conditions was analysed at various densities of the weeds planted immediately after rice transplanting.
The results obtained were as follows;
1) The plant length of the weeds grew toller at lower planting densities, and shorter at higher densities (Figs. 2 and 3). However, in both cases, the weeds grew enough to cover the area between rice rows and hills after midseason drainage.
2) The larger the top dry weight of the weeds in mid-September, the smaller the whole top-weight of the rice community and the lower the yield of rice (Fig. 4).
3) The decrease of rice yield which was mainly caused by nutrient competition with the weeds resulted firstly in the decrease of the number of ears, secondly in the decrease of the number of grains per ear when the weeds grew at higher densities, and thirdly in the decrease of the percentage of ripened grains when the weeds grew at lower densities (Table 1).
4) The ratio of rice yield loss to top dry weight of the weeds was higer for arrowhead than for other main paddy weeds (cf. Echinochloa oryzicola, Cyperus serotinus, Eleocharis kuroguwai). Presumably due to the high content of nitrogen in arrowhead plants.
5) A negative high correlation between the top dry weight of the weeds in mid-September and the number of rice ears was obtained in rice cultivated under ordinaly conditions from 1980 to 1984. It was considered that 100g/m2 of top dry weight of the weeds was equivalent to a loss of rice yields amounting to 12-15% (Fig. 6).View full abstractDownload PDF (611K) -
Hiroshi MATSUMOTO, Toru TOMINAGA, Tadashi SUMIYOSHI, Masaji KOSHIOKA1988 Volume 33 Issue 1 Pages 55-64
Published: May 26, 1988
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSDownload PDF (1191K)
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