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Volume 84 (2015)
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Volume 84, Issue 4
Displaying 1-12 of 12 articles from this issue
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Regular Paper
Agronomy
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Youichi Ohdaira, Ryouji Sasaki2015 Volume 84 Issue 4 Pages 345-350
Published: 2015
Released on J-STAGE: October 29, 2015
JOURNAL FREE ACCESSTo control volunteer rice derived from dropped seeds of forage rice, we examined the effects of the timing of seed embedding on the overwintering ability at two places. In Fukuyama city, Hiroshima, altitude 2 m, viability index (VI:percentage of seeds germinable after wintering) of cultivar “Kusanohoshi” embedded into soil in mid to late October was lower than that of the seeds embedded in mid-November to early-December and that of those overwintered on the soil surface. Similar results were observed in the deeper dormancy line “Chugoku-shi 189”. However, degree of the decreasing VI due to embedding in “Chugoku-shi 189” was smaller than that in “Kusanohoshi”. There was a negative correlation between VI and the percentage of seeds with a trace of germination after wintering (PT) in Fukuyama. These results suggest that seeds embedded in mid-late October had a low VI due to easy germination during wintering. PT increased with increasing cumulative air and soil temperatures (lower limit temperature, 10°C) up to 100°C and 130°C, respectively, by the end of the year. Thus it is suggested that generation of volunteer rice can be reduced by plowing in autumn when the effective cumulative temperatures are obtainable. In Iinan town, Shimane, altitude 425 m, VI of seeds embedded into soil in mid-October was lower than that of seeds overwintering on the soil surface. However, degree of the decreasing VI of “Kusanohoshi” due to embedding in Iinan was smaller than that in Fukuyama. PT in Iinan was not as high as in Fukuyama. Such regional differences may be caused by precipitation and soil temperature after autumn. Thus, appropriate selection of cultivar and setting of timing of plowing may be necessary.View full abstractDownload PDF (1206K) -
III. Regularity of Tiller Appearance and Varietal DifferenceHideharu Araki2015 Volume 84 Issue 4 Pages 351-357
Published: 2015
Released on J-STAGE: October 29, 2015
JOURNAL FREE ACCESSSynchronous emergence of leaf and tiller has been theorized for rice and wheat but not for winter wheat in Hokkaido. This study investigated the pattern of tiller appearance and its difference from synchronous appearance in “Kitahonami”, a main winter wheat in Hokkaido for three years. Furthermore, the varietal difference in the pattern of tiller appearance was investigated. In “Kitahonami”, concerning the primary-order tillers T1 appeared as expected from the synchronous theory, but T2 and T3 appeared slightly earlier, and T5 and higher tillers later. Concerning the second to fourth-order tillers, all tillers appeared earlier than expected, except for T13. Increase in leaf age after the appearance of tiller was approximately the same at all tillering nodes on the main stem, showing the regularity of synchronous leaf emergence. Tiller appearance was earlier than expected in all varieties examined, but it was later in “Tsurukitchi” than in “Kitahonami” and “Yumechikara”. Thus, in winter wheat in Hokkaido tillers appeared earlier than expected from synchronous emerging pattern, and it was earlier from the initial growth stage, It was also found that earliness of tillering in the initial growth stage varied with the variety. Because increased tillering before wintering would increase the number of ears per plant and yield of winter wheat in Hokkaido, earliness of tiller appearance before winter could be useful for effective selection of high-yield varieties.View full abstractDownload PDF (1217K) -
Izumi Tsujita, Takanori Oomori, Hiroshi Kimura, Hideki Sugimoto2015 Volume 84 Issue 4 Pages 358-368
Published: 2015
Released on J-STAGE: October 29, 2015
JOURNAL FREE ACCESSThe cultivar differences in the effects of early-sowing (late October) and late-sowing (mid December) on the yield and quality of naked barley (Hordeum vulgare var. nudum) were investigated using three cultivars (Manenboshi, Haruhimeboshi and Hinodehadaka). In early-sowing in which the plants grow in a short-day condition, the number of days from sowing to heading was increased and the yield was increased due to a vigorous initial growth and the large number of grains per unit area. However, the spike number and the number of grains per spike were decreased especially in Hinodehadaka and Haruhimeboshi due to the overluxuriant growth and cold injury in warm winter or late frost year. The total nitrogen content at anthesis in early-sowing increased resulting in increased steel-grain rate and reduced pearled grain whiteness. In late-sowing in which the plants grow in a long-day condition, the number of days from sowing to heading was decreased and the yield was decreased due to the small number of grain per unit area. These trends were marked in years with a cold winter or warm spring. Late-sowing increased grain protein content, steel-grain rate and decreased pearled grain whiteness. In addition, in late-sowing, rain in ripening period reduced the volume weight and grade of grain.View full abstractDownload PDF (3996K) -
Katsunori Isobe, Ryuji Sato, Seigo Sakamoto, Tatsuya Arai, Misa Miyamo ...2015 Volume 84 Issue 4 Pages 369-377
Published: 2015
Released on J-STAGE: October 29, 2015
JOURNAL FREE ACCESSThe objectives of this study were to evaluate the optimum planting density of quinoa (Chenopodium quinoa Willd.) variety NL-6 from the standpoint of efficiency for light utilization, dry matter production and seed yield. Field experiments were carried out in the experiment field at Nihon University in 2012, 2013 and 2014. In 2012, the row width was 50 cm, and the planting density was from 50 to 300 plants m-2. In 2013, the row width was 30 cm, and the planting density was from 100 to 400 plants m-2. In 2014, the planting density was 100 plants m-2, and the row width was from 15 to 60 cm. In the case of 50 cm row width, there were no significant differences in the extinction coefficient and relative illuminance on the soil surface at flowering and seed filling stage, in crop growth rate (CGR) from flowering to seed filling stage, and in seed yield among plots. In the case of 30 cm row width, the extinction coefficient and the relative illuminance on the soil surface in 300 and 400 plants m-2 were higher than those in 100 and 200 plants m-2, and the relative illuminance on the soil surface was lower at flowering and seed filling stage. However, there were no significant differences in the CGR from flowering to seed filling stage and seed yield among plots. The extinction coefficient in the 15 and 30 cm row width plots was higher than that in the 60 cm row width plot, and the relative illuminance on the soil surface was lower at flowering and seed filling stage. At a lower planting density and wider row width plots, the seed yields in the branch were higher than that in higher planting density and narrower row width plots. Therefore, we concluded that quinoa variety NL-6 needs from 50 to 100 plants per m-2 to get high seed yield regardless of planting density and row width. Seed yield was significantly correlated with the top dry weight at the seed filling stage (r=0.701*). Thus, the heavy dry weight at the seed filling stage is very important to increase the seed yield of quinoa variety NL-6.View full abstractDownload PDF (2138K) -
Fumitaka Shiotsu, Masanori Toyota, Akihito Kusutani2015 Volume 84 Issue 4 Pages 378-385
Published: 2015
Released on J-STAGE: October 29, 2015
JOURNAL FREE ACCESSThe differences in source/sink balance and yield formation among 33 Japanese and 17 foreign wheat cultivars bred in different eras were evaluated using individual kernel weight, the number of kernels m-2 and total dry matter at heading and maturity in a field experiment. The mean individual kernel weight (KW) at maturity of the spike from which two-thirds of spikelets were removed at the heading stage was assumed as an index of the potential maxim kernel weight (PKW). The source/sink balance of cultivars were evaluated by the ratio of KW/PKW which represents the ratio of kernel filling by its sink strength to PKW. The products of total number of kernel (N) and KW were assumed as the yield. The yield formation was evaluated by the increase in total dry matter from heading to maturity (amount of dry matter produced at ripening stage) and the contribution of the dry matter accumulated before heading among the yield. The mean KW/PKW of the domestic cultivars bred after 1980s was higher (0.783) than those bred before 1980s (0.730). Some of the foreign cultivars also had higher KW/PKW (0.751–0.810). The ratio of dry matter accumulated before heading to the yield exceeded 30% in 9 of 21 cultivars bred before 1980s. Some foreign cultivars showed negative KW/PKW, which implied that yield formation depended only on the amount of dry matter produced at the ripening stage. The cultivars used in this study were classified into two groups with KW/PKW higher than 0.741 (I) and lower than 0.741 (II), and also into these groups with a ratio of dry matter accumulated before heading to yield higher than 21.2% (A), 0% to 21.2% (B) and less than 0 % (C).View full abstractDownload PDF (887K)
Genetic Resources and Evaluation
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Yasuyuki Yoshimura2015 Volume 84 Issue 4 Pages 386-407
Published: 2015
Released on J-STAGE: October 29, 2015
JOURNAL FREE ACCESSSustainable agriculture, which reduces environmental burden, has become increasingly important in recent years. C4 plants are considered to be useful plant resources as both food and energy crops, because they show high dry matter productivity with high water and nitrogen use efficiencies. However, the studies on the effective use of C4 plants is not sufficient. In fact, the basic knowledge is scarce on many C4 plants except for a few crops. The C4 plants occurring in Japan are listed in this study, as a first step to utilize C4 plants including weeds. There are 419 C4 plant species belonging to 91 genera in 11 families, identified in Japan. They are comprised of 62 eudicot species belonging to 19 genera in 8 families, and 357 monocot species belonging to 72 genera in 3 families. Compared to the checklist in 1990, 19 eudicot species and 157 monocot species have been added to the list. C4 eudicots belonging to Aizoaceae, Asteraceae and Cleomaceae have newly been identified. However, C4 eudicots belonging to Acanthaceae, Boraginaceae, Caryophyllaceae, Molluginaceae and Scrophulariaceae have not been found in Japan. Monocot submerged aquatic plant, Hydrilla verticillata in Hydrocharitaceae has been found to induce C4 photosynthetic metabolism under conditions of low CO2 concentration in water. This finding has increased the family number of C4 monocots to 3. The list has 6 C3-C4 intermediate species, 5 of which have newly been identified as introduced plants. Lots of C4 plants identified newly in Japan, more exactly, 84% of C4 eudicots and 46.8% of C4 monocots are the introduced plants including cultivated species. This indicates that C4 plant seeds have contaminated imported raw materials, and invaded Japan in the same way as other introduced weed seeds.View full abstractDownload PDF (1166K)
Modelling, Information and Environment
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Satoshi Nakano, Etsushi Kumagai, Shinji Shimada, Ryoji Sameshima, Hiro ...2015 Volume 84 Issue 4 Pages 408-417
Published: 2015
Released on J-STAGE: October 29, 2015
JOURNAL FREE ACCESSThis study aimed to estimate the large-scale effects of elevated air temperature on the phenological development of soybean by using the agro-meteorological grid data. A logistic model has been developed for describing the developmental rate (DVR) of three soybean cultivars, Ryuhou, Enrei and Fukuyutaka. Root mean square errors of the model estimation ranged from 1.4 to 2.2 days for emergence (VE) to flowering (R2) and 1.2 to 2.8 days for R2 to beginning of seed growth (R5). The model could estimate the effect of elevated air temperature on phenological development in a temperature gradient chamber. The response of DVR to air temperature change from VE to R2 was larger in the medium cultivar, Ryuhou, Enrei, than in the late cultivar, Fukuyutaka. The elevated air temperature simulation (+3°C) resulted in shortened duration of VE to R2 in the cool, early sowing region of eastern Japan by 5 to 7 days, whereas little effect was observed in the warm, late sowing region of Kyushu, in southern Japan. This large influence of elevated air temperature on the phenological development of soybean in eastern Japan was not only because of the use of cultivars sensitive to air temperature change but also because of the range of regional air temperatures, which largely alters the DVR during the cultivation period.View full abstractDownload PDF (1717K)
Research and Technical Note
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Masami Furuhata2015 Volume 84 Issue 4 Pages 418-425
Published: 2015
Released on J-STAGE: October 29, 2015
JOURNAL FREE ACCESSSeedling emergence was examined in direct sowing culture on well-drained paddy fields at low temperatures. Germination characteristics were assessed under aerobic conditions and coleoptile elongation under anaerobic conditions associated with seedling emergence. The experiments included 138 domestic and foreign rice cultivars. The speed of seedling emergence was positively correlated with the final seedling emergence rate and early plant growth. The speed of coleoptile elongation under anaerobic conditions was not correlated with the speed of seedling emergence, suggesting that coleoptile elongation under anaerobic conditions was not related to seedling emergence. The speed of germination was positively correlated with the speed of seedling emergence, suggesting that the speed of germination affects the speed of seedling emergence and consequently the final seedling emergence rate and early plant growth. I concluded that early germination was important for seedling emergence and establishment in direct sowing culture on well-drained paddy fields at low temperatures.View full abstractDownload PDF (945K) -
Hiroyuki Shiratsuchi, Youichi Ohdaira, Hiromichi Yamaguchi, Akari Fuku ...2015 Volume 84 Issue 4 Pages 426-431
Published: 2015
Released on J-STAGE: October 29, 2015
JOURNAL FREE ACCESSA puddling seeder with a paddy harrow, two fertilizer applicators as seeding units, and a roller was developed to realize direct seeding of pregerminated rice seeds in the cool region in Japan. To determine the appropreate number of puddling and seeding pattern, we investigated the effects of puddling frequency and seeding pattern that is puddling once or twice, and seeding in thick rows or broadcasting, respectively, on seedling establishment and yield from 2010 to 2013 in Daisen, Akita, Japan. Seedling length and number of leaves were higher in puddling twice than in puddling once, while maximum stem number, lodging, dry weight at heading and maturity, and yield were not affected by the number of puddling. Because higher leaf number in an early stage is an advantage in weed control, the twice puddling was adopted for the further studies. Early growth, maximum stem number, lodging, dry weight at heading and maturity, and yield were not affected by the seeding patterns. Broadcasting was adopted for the further studies because the mechanism of the seeder was simple and vegetation rate higher.View full abstractDownload PDF (1232K) -
Nobuki Chida, Dong-Sheng Han, Hajime Watanabe, Yoshihiko Takahashi2015 Volume 84 Issue 4 Pages 432-438
Published: 2015
Released on J-STAGE: October 29, 2015
JOURNAL FREE ACCESSPaddy rice chlorophyll meters can measure leaf color values in real time. Because of that accumulation of test data, it is becoming increasingly popular in research on paddy rice cultivation, as well as in extension services and education organizations. However, the meter only measure one section of each leaf. To obtain representative values, we need to measure of several points on each leaf, and thus it is time consuming. In recent years, photographs taken by common household digital cameras have been used to evaluate canopy color in paddy rice. In this study we assessed the efficiency and accuracy of this method. We separated color images of paddy rice canopies into RGB images, using commonly available image analysis software, and binarized these images. We then compared the synthetic image with the original color image. We copied the paddy rice leaf color chart onto the lower part of the screen when taking photographs, to act as color standards, and created calibration curves. For each of the three relevant growth stages (maximum-tiller-number, panicle formation, and nine days before heading), the correlation coefficient between the leaf color chart value and the measured leaf color value (chromaticity) was r=0.80 or above, and the relationship was significant. This method allows more efficient evaluation of rice paddy nutrition than the use of chlorophyll meters. Furthermore, it give valuable information for making decisions about topdressing, which is done to prevent the degradation of rice that can occur during ear ripening at high temperatures.View full abstractDownload PDF (2332K) -
Akira Fukushima, Hisatoshi Ohta, Ryota Kaji, Naoto Tsuda2015 Volume 84 Issue 4 Pages 439-444
Published: 2015
Released on J-STAGE: October 29, 2015
JOURNAL FREE ACCESSLow percentage of germination and emergence has been a serious problem in cultivation of feed rice varieties in the Tohoku region of Japan. In order to elucidate the factors causing low percentage of germination, we investigated the effects of hot water disinfection and cold water seed soaking on germination using 20 rice varieties including feed rice varieties of Tohoku region. Hot water disinfection for a long time (60°C, 30 minutes) decreased the germination percentage more in feed rice varieties, glutinous rice varieties, and indica type varieties than in food rice varieties. Among the feed rice varieties in the Tohoku region, “Bekogonomi”, “Bekoaoba”, “Iwaidawara”, “Ushiyutaka” and “Yumeaoba” showed a lower germination percentage. The rice seed after sprouting treatment showed the low germination percentage after hot water disinfection, suggesting that the germination rate of feed rice varieties with weak sprouting resistance tends to decrease the percentage of germination after hot water disinfection. Seed soaking at 5°C decreased the germination percentage in some feed rice varieties in the Tohoku region, although soaking at 12°C did not. These results suggest that hot water disinfection for a long time and soaking in very cold water tended to decrease the getmination percentage in some feed rice varieties in the Tohoku region.View full abstractDownload PDF (708K)
Information
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[in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...2015 Volume 84 Issue 4 Pages 445-446
Published: 2015
Released on J-STAGE: October 29, 2015
JOURNAL FREE ACCESSDownload PDF (613K)
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