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Volume 69, Issue 4
Displaying 1-17 of 17 articles from this issue
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Susumu TOYAMA2000 Volume 69 Issue 4 Pages 453-463
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESS -
Hisao NAKANO, Miyuki HIRAI, Shinichi SUGIMOTO, Yasuo TOMIHISA2000 Volume 69 Issue 4 Pages 464-469
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSRice-Chinese milk vetch was cultivated by a rotation system from 1994 to 1997 to examine the effect of rice straw on the establishment and growth of Chinese milk vetch. Chinese milk vetch was sown in rice stands. Rice was sown under 2 different land preparation conditions ; no-tillage(NT), i.e., sod-seeded, and tillage(TA), in which green Chinese milk vetch and rice straw from the previous year were incorporated into the soil. A poor establishment of Chinese milk vetch in the NT plot was observed only in 1996. The percentage of canopy closure of Chinese milk vetch in both treatments decreased year by year, especially in NT :40%, 15%, and 5% in 1995, 1996, and 1997, respectively. When rice straw was removed after rice harvest in the NT plot, the canopy closure of Chinese milk vetch was fairly recovered. The seedlings of Chinese milk vetch planted on soil collected from the NT plot showed poor growth, compared with those planted on soil collected from the TA plot. When rice straw was put on the soil surface, the seedling growth was inferior to that on the bare surface, especially the root growth. These results suggested that an allelopathic substance released from rice straw inhibited the establishment and growth of the seedlings of Chinese milk vetch.View full abstractDownload PDF (937K) -
Hisao NAKANO, Miyuki HIRAI2000 Volume 69 Issue 4 Pages 470-475
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSUnder the conditions of a continuously rice and Chinese milk vetch rotation system during the nontillage cultivation, the vegetation of Chinese milk vetch become poorer year by year. The effects of the aqueous extracts from rice straw on the germination and on the growth of Chinese milk vetch were examined. In the 1st experiment, allelopathic rice-straw substances extracted with water(RE)were added to petri dishes at 7 concentrations, and Chinese milk vetch was seeded 2 days after imbibition. The higher the RE concentration, the lower the germination and growth rates, especially the rate of growth of the radicle. At a high RE concentration, the tip of the hypocotyl became black, and all seedlings died within 12 days after seeding. In the 2nd experiment, Chinese milk vetch was sown on a tray with soil, and covered with 2 kinds of rice straw, one with RE removed(RES), and the other with RE retained(CS). The growth of the seedlings in CS was significantly poorer than that in RES. At 20 days after seeding, the survival percentage was about 100% and 30% in RES and CS, respectively. In the 3rd experiment, pots covered with rice straw(RS)or without rice straw(NS)were placed in a greenhouse under a flooded condition from July to September, and at 20 days after natural drying the seedlings of Chinese milk vetch at the cotyledon stage were transplanted in the pots. The growth in RS was inferior to that in NS, especially in radicles. These results indicated that the extracts from rice straw inhibited the germination and growth of Chinese milk vetch. It is considered that the water-soluble allelopathic substances in rice straw were accumulated in the field during nontillage cultivation of Chinese milk vetch and rice.View full abstractDownload PDF (890K) -
Tsuyoshi OKAMOTO, Teruhisa UMEZAKI, Yuichi NAGAYA, Tetsuro TANIYAMA2000 Volume 69 Issue 4 Pages 476-480
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTo make a new growing area for Chinese yam(D.opposita Thunb.), producers need a lot of rhizophore for seed. To establish an efficient cultural technique for its seed propagation, we examined the effects of seed rhizophore weight and planting density on the yield at a commercial field in 1997 and 1998. The suitable size of rhizophore for seed is different from the size for fresh market. The weight of new rhizophore was reduced by reducing the seed rhizophore weight or increasing the planting density. The smaller the seed rhizophore, however the lower the yield. The higher the planting density, the lower the propagation rate of new rhizophore to seed one. With their combination, the problems were resolved. The optimum seed rhizophore weight and planting density of the standard variety GSIA for seed propagation were 20g and 8, 333 plants per 10a, each "Shintanmaru" was 10g and 16, 667 plants per l0a. Under these conditions, all rhizophores were under 350g(cut in four with a standard variety or in eight with "Shintanmaru"). With the smaller seed rhizophore weight and the higher planting density, it could provide smaller new rhizophore for seed in "Shintanmaru."View full abstractDownload PDF (1082K) -
Satoshi YOSHINAGA, Mizuhiko NISHIDA, Kenzo WAKIMOTO, Kohei TASAKA, Ken ...2000 Volume 69 Issue 4 Pages 481-486
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDrainage after seeding has recently been practiced in general for the improvement of seedling emergence in submerged direct-seeding rice(Oryza sativa L.)cultivation. We examined the relationship between water management after direct-seeding and the effectiveness of fertilized nitrogen to clarify the effects of drainage on the growth and yield of rice. It was confirmed that the drainage after seeding improved the seedling emergence rate and stimulated the initial growth of the seedling. When controlled release fertilizer(LPl00)was applied as basal dressing, water management after seeding had no effect on the growth and yield. However, when ammonium sulfate was applied, the yield was reduced by the drainage after seeding, due to the decrease in nitrogen uptake of rice at the panicle initiation stage, and resulting reduction in the number of spikelets. In this case, nitrogen uptake seemed to be reduced because nitrogen uptake in the early growth stage was increased by the increase in initial growth and tillering and because the content of ammonium nitrogen in soil was reduced by nitrification of the fertilized nitrogen during drainage. These results showed that the suppression of nitrogen uptake at the initial growth stage and the avoidance of nitrogen deficiency at the intermediate growth stage, are important to stabilize not only seedling emergence but also growth and yield for the management of drainage after seeding.View full abstractDownload PDF (1022K) -
Yosuke UCHIMURA, Takefumi OGATA, Hirokazu SATO, Yuji MATSUE2000 Volume 69 Issue 4 Pages 487-492
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe effects of silicon application on lodging, yield and palatability of rice grown in a low-SiO2 field by direct sowing culture were studied. The silicon application increased lodging resistance through increased breaking strength and increased pushing tolerance. It also increased the yield by increasing the percentages of ripened grains. The palatability of the rice grown with silicon applications tended to be superior to the rice grown without silicon application. The silicon applications lowered the protein contents in milled rice and increased the maximum viscosity. Therefore, it was concluded that the superiority of palatability under the direct sowing culture with silicon application was caused by the reduction of protein content and an increase in the maximum viscosity, which was closely related to the extent of grain filling. These effects were clearly observed by the application of 64gm-2 or more silicon.View full abstractDownload PDF (979K) -
Hisashi TANNO, Masahumi KINOSHITA, Hitoshi KIUCHI, Yuji HIRAYAMA, Haru ...2000 Volume 69 Issue 4 Pages 493-499
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSCool-weather tolerance at the flowering stage of 52 Hokkaido rice varieties was examined in 1998 and 1999. Eight plants having only the main culm were cultivated in small square pots, 15×5×10cm, and were tested by means of a 15-day treatment at 17.5°C, starting from the heading day of tested plants, in an air conditioned room with 50% shading. Among the varieties tested, Hayayuki and Hayakogane had the highest tolerance(estimated ranking was high to extremely high). Akage, Fukuyuki, Uryuu, Hoshinoyume, and Hatushizuku had high tolerance(high), and Fukoku, Wase nishiki, and Shimahikari had the lowest tolerance(low to extremely low). Between the tolerances at the booting stage and the flowering stage, a significant positive correlation was observed(r=0.54l). Although the variety or which the registered year as the recommmended variety was more recent had higher cool tolerance at the booting stage(r=-0.366), no correlation was found between the registered year and the cool tolerance at the flowering stage(r=-0.055ns), and it was concluded that to breed high-cool tolerant varieties at the flowering stage, direct selections for cool tolerance are needed in the breeding program. Moreover, 37 breeding lines, which had extremely high tolerance at the booting stage, were tested for tolerance at the flowering stage, and it was found that Eikei 88223 and Hokuiku mochi 87 had an extremely high tolerance at the flowering stage too. These lines are considered to be a desirable parent for cool tolerance.View full abstractDownload PDF (1150K) -
Tomio WATANABE, Katsuyuki ARIHARA, Yasuyuki NISHIKAWA2000 Volume 69 Issue 4 Pages 500-507
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSIn 1995, Chiba Prefectural Agricultural Experiment Station bred a new paddy rice cultivar "Fusaotome" which is tolerant to cool weather, early maturing(same as "Hananomai"), and has high grain-quality and excellent flavor with heavy grain weight(exceed "Hananomai" by 1.0-1.5g in 1000-kernel-weight). We determined the recommended target of the husked-rice yield to be 5.4-6.0 ton/ha in sandy/loam soil fields, and 5.4-5.7 ton/ha in clay soil fields. In order to achieve these target yields, the necessary numbers of grains and panicles were 28, 000-32, 000 and 480-510 per m2, respectively, in sandy soil fields, and 28, 000-32, 000 and 450-480, respectively in loam soil fields. In clay soil fields, the necessary number of grains was 28, 000-30, 000 per m2 and that of panicles was 470-500 per m2. In order to secure the above number of panicles, the necessary basal dressing of nitrogen fertilizer was 40-50 kg/ha in sandy, 30-40 kg/ha in loam and 10-20 kg/ha in clay soil fields, and the necessary top dressing at 18 days before the heading stage was 30kg/ha in sandy and loam and 10-20 kg/ha in clay soil fields. The delay of transplanting made it difficult to achieve the above values and caused the growth of tall culms and severe lodging, resulting in lowering of the grain quality. Therefore, the transplanting should be done by the end of April.View full abstractDownload PDF (1248K) -
Hideki YOSHIOKA, Hiroshi KAWAGOE2000 Volume 69 Issue 4 Pages 508-512
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe effects of climatic factors on heading of early-planting rice cultivars were discussed. Growing period from transplantation to heading was divided into three phases, i.e.phase I ; from the day of transplantation to the first day of tillering, phase II ; the first tillering day to the first day of panicle formation, and phase III, the first day of panicle formation to first day of heading. The heading time of Koshihikari was affected by climatic factors in phase II, and that of Kirarimiyazaki by climactic factors in both phase I and II. Heading days was highly correlated with the mean air temperature during the first half of phase II in Koshihikari, and throughout phase II in Kirarimiyazaki. In l998, temperature in phase I and II was very high, which reduced growing days, and decreased the cumulative temperature necessary for rice growth. The reduction in growing days was especially great in Koshihikari, and this might cause the reversed heading date between Koshihikari and Kirarimiyazaki in 1998.View full abstractDownload PDF (770K) -
Akio SUMI, Tadao C.KATAYAMA2000 Volume 69 Issue 4 Pages 513-519
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe effects of nitrogen fertilizer application and solar radiation on the growth response to soil moisture were examined in sorghum seedlings grown in culture boxes. The effects of soil moisture(f)and amount of nitrogen fertilizer application(g)on the increment of total dry matter weight of sorghum seedling(〓W)were represented satisfactorily by the following reciprocal equation, l/〓W=A/(f-f0)+B(g+g0)/(f-f0)+C/[(f-f0)(g+g0)]+D/(g+g0)+E, where f0 and g0 were the uppermost value of unavailable soil moisture and the amount of nitrogen supplied from soil and seeds. A, B, C, D and E were coefficients. The effects of soil moisture(f)and solar radiation(S)on 〓W were expressed approximately by the following reciprocal equation, l/〓W=A/(S-S0)+B/(f-f0)+C(f-f0)+D, where S0 was the daily compensation point. These results indicated that the effects of solar radiation and soil moisture are additive, but the interaction between soil moisture and nitrogen fertilizer is not negligible. The transpiration efficiency was unaffected by soil moisture, nitrogen fertilizer and solar radiation.View full abstractDownload PDF (1083K) -
Shao-Hui ZHENG, Ryuta WATABE2000 Volume 69 Issue 4 Pages 520-524
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSExudation from imbibing seeds causes failure of seedling emergence under excessive soil-moisture conditions. We investigated the relationship between sugar exudation from imbibing seeds and seedling emergence under suitable and excessive soil-moisture conditions in 20 soybean cultivars. Seeds in one group(aged seeds)were exposed to 40°C and 100% relative humidity for six days and those in another group(control seeds)were not. The amount of sugars(fructose and glucose)exuded varied from 0.4mg(cv.Moyashimame)to 11.8mg(cv.Shirotae)per gram seeds in control seeds, but was larger in most of the aged seeds. The exudation was obviously great in the cultivars with yellow seed coat in both control and aged seeds. The percentage of seedling emergence in the control seeds was high irrespective of the soil moisture conditions, but that in the aged seeds was lower in particular under excessive soil-moisture conditions. A significant negative correlation between sugar exudation and the percentage of seedling emergence under excessive soil-moisture conditions suggesting that sugar exudation is highly correlated with the seedling emergence. In some cultivars with black seed coat, sugar exudation from aged seeds was low, and the percentage of seedling emergence under excessive soil-moisture conditions was higher than that in other cultivars. These cultivars considered to retain the character of seed vigor.View full abstractDownload PDF (787K) -
Satoru KINEFUCHI, Kunio HAMAMURA2000 Volume 69 Issue 4 Pages 525-529
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSTo estimate leaf water potential by measuring leaf greenness of Melon(Cucumis melo L.), leaf water potential(ψleaf)and leaf greenness value(〓D)were measured successively in a day. Both ψleaf and 〓D oscillated diurnally ; ψlear decreased during day and increased during night, and 〓D increased during day and decreased during night. Their changes were highly correlated negatively. They were more closely correlated during night than during day and more closely in old leaves than in young ones. A factor causing the discrepancy was considered to be new chlorophyll formation in young leaves during daytime. We consider it highly feasible to use 〓D as an indicator to know ψlear after substructing other background effects, such as varietal characteristics, nitrogen fertilizer level, and amount of solar radiation, and to utilize it for precise irrigation control.View full abstractDownload PDF (785K) -
Masami YAMAUCHI, Hirokazu YOSHIDA, Tetsuro TANIYAMA, Teruhisa UMEZAKI, ...2000 Volume 69 Issue 4 Pages 530-534
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe concentration of fluorine to the public water bodies permitted by water pollution law is 15 mg L-1. The growth of rice plants was severely depressed by fluorine added to the culture solution at 5-10 ppm. The purpose of this investigation was to make clear the limit value of fluorine on the growth of rice plants and to clarify the absorbing mechanism by the roots of rice plants. The effect of the fluorine(HF)added to the culture solution at 0, 2, 4 and 6 ppm on the growth of Oryza sativa L.cv.Koshihikari was investigated. The increase in the leaf length and the number of stems per hill was depressed by the fluorine added. Especially, the number of stems per hill was obviously decreased by increasing the concentrations of HF. The number of ears and unhulled rice per hill were decreased by the lower concentrations of HF. It was clarified that the dry weights of unhulled rice, leaves, and roots were markedly decreased by fluorine at the lower concentrations. The fluorine content in leaves increased by increasing the concentration of HF and prolonging the growth period. It was shown that the fluorine absorbed through the roots was accumulated in brown rice, leaves, stems and roots.View full abstractDownload PDF (823K) -
Masami YAMAUCHI, Hirokazu YOSHIDA, Tetsuro TANIYAMA, Teruhisa UMEZAKI, ...2000 Volume 69 Issue 4 Pages 535-539
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSThe effect of fluorine(HF)added to the irrigation water at 0, 5, 10, 20, 30, 50 and 100 ppm under the soil culture on the growth of Oryza sativa L.(cv. Koshihikari)was investigated. The effects of leaf-emergence rate, plant length and number of stems per hill were not observed by 5-30 ppm concentrations of fluorine added to the irrigation water. The number of stems per hill and photosynthetic activity of the leaves were obviously decreased by 50 and 100 ppm concentradons of HF. The chlorophyll contents in the leaves were not affected even by a low concentration of fluorine. The number of ears and grains per hill were decreased by the concentrations of 50 and 100 ppm in the irrigation water. It was clarified that the dry weights of unhulled rice, leaves and stems were markedly decreased by the concernrations of 50 and 100 ppm HF added to the irrigation water.View full abstractDownload PDF (760K) -
Eiji KANDA, Yoichi TORIGOE, Takashi KOBAYASHI2000 Volume 69 Issue 4 Pages 540-546
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSWe are building an early warning system for preventing the decrease in rice-yield by cool summer damage. To monitor the developmental stage of rice plants in the whole Tohoku area, we constructed a model for estimating the plant age in leaf number. In the model, the sum of effective cumulative air temperature for l0-24°C necessary to advance the leaf number on the main culm by one was defined as the leaf emergence interval. The model predicts the plant age from effective cumulative air temperature. The leaf emergence interval was assumed w be constant in Phase I(before the leaf age 9.1), increase at a fixed rate in Phase II(between leaf age 9.1 and 11.1), and to be constant in Phase III(after leaf age 11.1). The parameters of the model were decided from the leaf-emergence interval of seven varieties among twelve leading varieties of Tohoku District in 1997 and 1998 in Morioka. The model estimated the leaf age of the 11 varieties excluding "Okiniiri" in Morioka in 1999 with the mean error of 0.25 leaf, which corresponds to 1.7 days. From the application of this model to the rice- growers' fields in Miyagi and Yamagata Pref., the adaptability of this model was validated. However, in the growth types with vigorous tillering, the prediction accuracy was low because the leaf emergence interval was influenced by the number of tillers.View full abstractDownload PDF (1156K) -
Takashi TASHIRO, Osamu SUGAWARA, Hiroshi NAGANOMA, Kazuo CHIBA, Masahi ...2000 Volume 69 Issue 4 Pages 547-553
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDirect-seeding culture without tillage and covering soil using the Y-shaped seeding furrow was examined in 1997 and 1998 at a poorly drained paddy field in Hachirogata(Akita Pref., Japan). The percentage of seedling establishment in the plots of polyolefin coated urea(CU)and sigmoid type of CU(SCU)were 50.3% and 44.7%, respectively, in 1997, and 35.7% and 35.3%, respectively, in 1998. The cumulative effective temperature from seeding to the establishment time was 147.6°C and l24.0°C in 1997 and 1998, respectively. The number of established seedling per m2 in the CU and SCU plots was 167 and 149, respectively, in 1997, and 119 and 118, respectively, in 1998. The brown grain yield per m2 in CU and SCU plots was 645 g and 621 g in 1997, and were 501 g and 472 g, respectively, in 1998. These results suggested that the direct seeding of rice on Y-shaped furrow without tillage and covering soil is highly feasible to keep the same level of the yield in the transplanted cultivation of rice in cool and clayey paddy fields in the Tohoku District.View full abstractDownload PDF (1181K) -
[in Japanese]2000 Volume 69 Issue 4 Pages 554-557
Published: December 05, 2000
Released on J-STAGE: February 14, 2008
JOURNAL FREE ACCESSDownload PDF (755K)
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