• Korean Journal of Weed Science
• /
• v.8 no.3
• /
• pp.250-257
• /
• 1988

The study was intended to know any relations between the rice tolerance to bensulfuron and varietal speciation in seed protein composition or any enzymatical allelies with or without chemical treatment. Rice varieties used were UCP-28, Chinsurah Boro II, Fukunohama, Fadehpur-2, IR 14252-13-2-2-5 as the tolerant group, and HP 93(3) FA, HP94(9) FA, Padilabou Alumbis, KH-17854, and IR 1846-2841-1 as the susceptible, respectively. Electrophoretic methods used were SDS-PAGE for seed protein, 7% PAGE for isozymes (acid phosphatase, peroxidase, malate dehydrogenase, and esterase from rice seedling) and variation in isoenzyme profiles (malate dehydrogenase, peroxidase, and esterase) as affected by different concentrations of bensulfuron(0, $10^{-6}$, $10^{-5}$ and $3{\times}10^{-5}M$) was also studied. The results are summarized as follows. -Among 16 bands separated in seed proteins, two different rice groups selected in terms of tolerance to bensulfuron were clustered in dissimilarity, which was based on relatively larger area in whole peaks and higher activities in N, O, P bands for the tolerant group. -Among isozymes obtained from rice seedlings without chemical treatments, the following specificities were obtained. The tolerant varieties had the relatively higher activity in D band out of 4 peroxidase bands. Malate dehydrogenase was separated into 3 bands and only tolerant varieties had A band and higher activities in Band C bands. Esterase was separated into 3-4 bands with higher activities in A and B bands for tolerant varieties. There were one major band accompanied by 2-3 minor bands for acid phosphatase in which only tolerant varieties had the B band. -The effect of Bensulfuron concentration on the isozyme activities showed that the activity of C band in peroxidase was not present in tolerant varieties which was contrary to the increased activities in susceptible varieties. However, D band was gradually disappeared only in susceptible varieties as the concentration of bensulfuron was increased. For malate dehydrogenase in the susceptible varieties, major bands D, E and F kept consistantly higher activities while minor bands A, B and C disappeared sensitively. Among 5 bands of esterase separated, D band was present only in the tolerant varieties while E band only in the susceptible. The activities in A, C, E bands were sharply decreased in the susceptible varieties as the concentration of bensulfuron was increased.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.9 no.1
• /
• pp.17-28
• /
• 2007

This study was conducted to analyze the optimum heading period according to the recent climatic change for improvement of rice yield and grain quality in the Yeongnam area. We analyzed climatic elements including daily mean air temperature, daily range of air temperature, sunshine hours, and amount of precipitation from 1996 to 2005 in comparison with those of the 1971 to 2000 normal. Daily mean air temperature and amount of precipitation in the recent 10 years increased, but daily range of air temperature and sunshine hours decreased in comparison with the norm. Also, monthly mean air temperature was lowered remarkably in July and August. The monthly amount of precipitation largely increased in August and September. The daily range of air temperature and sunshine hours were greatly decreased from August to October, Possible cultivation periods for rice in the recent 10 years ranged from 171 days in Boughwa to 228 days in Busan and was expanded about $1{\sim}13$ days in comparison with the normal. Optimum heading date by local regions for the maximum climatic yield potential was estimated as July 31 at Bonghwa to September 7 at Busan, Masan, and Tongyeong in the recent 10 years. There was a wide difference in optimum heading date according to local legions of the Yeongnam area. Compared to the normal, optimum heading date in the recent 10 years was delayed about I~8 days in most local regions except Bonghwa, Mungyeong, and Yeongdeok. These results suggested that it is necessary to develop late maturity rice cultivars for producing high yield and quality rice grain due to the recent climatic change. Moreover, it is still more important to select the most suitable cultivation period appropriate to the changed climate of each local region in Yeongnam area.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.14 no.3
• /
• pp.132-141
• /
• 2012

Climate change impact assessment of cereal crop production in South Korea was performed using land attributes and daily weather data at a farm scale as inputs to crop models. Farmlands in South Korea were grouped into 68 crop-simulation zone units (CZU) based on major mountains and rivers as well as existing land use information. Daily weather data at a 1-km grid spacing under the A1B- and RCP8.5 scenarios were generated stochastically to obtain decadal mean of daily data. These data were registered to the farmland grid cells and spatially averaged to represent climate conditions in each CZU. Monthly climate data for each decade in 2001~2100 were transformed to 30 sets of daily weather data for each CZU by using a stochastic weather generator. Soil data and crop management information for 68 CZU were used as inputs to the CERES-rice, CERE-barley and CROPGRO-soybean models calibrated to represent the genetic features of major domestic cultivars in South Korea. Results from the models suggested that the heading or flowering of rice, winter barley and soybean could be accelerated in the future. The grain-fill period of winter barley could be extended, resulting in much higher yield of winter barley in most CZUs than that of rice. Among the three major cereal grain crops in Korea, rice seems most vulnerable to negative impact of climate change, while little impact of climate change is expected on soybeans. Because a positive effect of climate change is projected for winter barley, policy in agricultural production should pay more attention to facilitate winter barley production as an adaptation strategy for the national food security.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.14 no.4
• /
• pp.161-169
• /
• 2012

The RCP 8.5 scenario based temperature outlook (12.5 km resolution) was combined with high-definition gridded temperature maps (30 m grid spacing) across the Korean Peninsula in order to reclassify the cold hardiness zone for winter barley, a promising grain crop in the future under warmer winter conditions. Reference maps for the January minimum and mean temperature were prepared by applying the watershed-specific geospatial climate prediction schemes to the synoptic observations from 1981 to 2010 across North and South Korea. Decadal changes in the January minimum and mean temperatures projected by a regional version of RCP8.5 climate change scenario were prepared for the 2011-2100 period at 12.5 km grid spacing and were subsequently added to the reference maps, producing the 30 m resolution temperature surfaces for 9 decades from 2011 to 2100. A criterion for threshold temperature to grow winter barley safely in Korea was applied to the future temperature surfaces and the resulting maps were used to predict the production potential of 3 cultivar groups for the 9 future decades under the projected temperature conditions. By 2020s, hulled barley cultivars could be grown safely at the southern part of North Korea as well as the mountainous Gangwon province. Furthermore, most of South Korean rice paddies will be safe for growing naked barley after harvesting rice. Also, dual cropping systems such as 'winter-barley after rice' could be possible at most of the North Korean rice paddies by 2040s. Additional grain production in North Korea could increase up to 4 million tons per year if dual cropping systems can be fully operated, i.e., winter barley after rice at all lowlands and winter barley after maize or potato at all uplands.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.59 no.4
• /
• pp.483-491
• /
• 2014

Double cropping system including paddy field soybean is widely adopted nationwide, due to rise in market price and its higher income than paddy field rice. Sowing date of soybean as a second crop is being delayed depending on first crop's growth period and harvesting time. Due to the increased temperature in October and delayed first frost date, soybean could be harvested without frost damage even in late-plating. Therefore, selection of soybean cultivar which is appropriate for this environment is very important. The effect of sowing date and genotype of soybean on growth and yield was investigated for three planting dates (June 20, July 5, and July 20) with ten cultivars developed for soy-pate production, to figure out plant development and yield pattern in delayed planting. As planting date is delayed, plant height and pod number was decreased and this pattern was more clearly detected in mid-late maturity cultivars. Hundred-seed weight did not show significant changes even in late planting, due to compensations between yield components. Yield reduction of July 20 in contrast to that of June 20 showed that Nampung (9.6%) showed the least yield decline. Maximum yield was achieved from Daepung, Taekwang, and Uram among other soybean cultivars in late planting. Shortening of growth period was strongly detected in reproductive stage while length of vegetative stage was regularly maintained in both early and mid-late maturity cultivars.

• Korean Journal of Agricultural Science
• /
• v.4 no.1
• /
• pp.51-60
• /
• 1977

In order to determine ecological variations of flowering date and yields under the different seasonal cultures, and to select the higher yielding varieties which were adaptable to Korean climate, 100 mungbean cultivars were sown at the interval of 15 days from April 22 to July 21 in 1976. The results obtained are summarized as follows: 1. The number of days required to flowering from seeding were decreased by delaying the seeding date. 2. When accumulated temperature at first flowering from seeding were reached $945-1,126^{\circ}C$, the mungbean cultivars started to flower regardless of seeding dates. Especially, when mungbean was planted around standard planting date, the plants flowered for very short duration. 3. There were highly significant correlations between the number of days from seeding to flowering at each seeding date and standard planting date. 4. Yields per plant were tend to decrease with the delay of seeding date but there were no significant difference between seeding dates. Therefore, it appears that mungbean can be planted for longer period of time compared to other crops such as rice and soybean. 5. Highly significant correlations were found between the number of days of first flowering and yields per plant at most seeding dates. 6. It may be feasible to grow high yielding mungbean cultivars such as CES 140, LM 2100, LM 690, L 576 and LM 689 after harvesting of spring vegetables in May and before planting of fall vegetables.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.24 no.3
• /
• pp.133-144
• /
• 2022

This study was conducted to investigate the cultivation period, adaptive genetic resources, growth and development patterns, and water consumption for rice cultivation in the desert environment of United Arab Emirates (UAE). R esearch on rice cultivation in the desert environment is expected to contribute to resolving food shortages caused by climate change and water scarcity. It was found that the optimal cultivation period of rice was from late November to late April of the following year during which the low temperature occurred at the vegetative growth stage of rice in the UAE. Asemi and FL478 were selected to be candidate cultivars for temperature and day-length conditions in the desert areas as a result of pre-testing genetic resources under reclaimed soil and artificial meteorological conditions. In the desert environment in the UAE, FL478 died before harvest due to the etiolation and poor growth in the early stage of growth. In contrast, Asemi overcame the etiolation in the early stage of growth, which allowed for harvest. The vegetative growth phases of Asemi were from early December to early March of the following year whereas its reproductive growth and ripening phases were from early March to late March and from late March to late April, respectively. The yield of milled rice for Asemi was 763kg/10a in the UAE, which was about 41.8% higher than that in Korea. Such an outcome was likely due to the abundant solar radiation during the reproductive growth and grain filling periods. On the other hand, water consumption during the cultivation period in the UAE was 2,619 ton/10a, which was about three times higher than that in Korea. These results suggest that irrigation technology and development of cultivation methods would be needed to minimize water consumption, which would make it economically viable to grow rice in the UAE. In addition, select on of genetic resources for the UAE desert environments such as minimum etiolation in the early stages of growth would be merited further studies, which would promote stable rice cultivation in the arid conditions.

• Journal of Mushroom
• /
• v.14 no.4
• /
• pp.136-141
• /
• 2016

The production scale of mushrooms in Korea is approximately 600 billion won, which is 1.6% of Korea's gross agricultural output. In Korea, ca. 190,000 tons of mushrooms are harvested annually. Although the numbers of mushroom farms and cultivators are constantly decreasing, total mushroom yields are increasing owing to large-scale cultivation facilities and automation. The recent expansion of the well-being trend has caused an increase in mushroom consumption in Korea: the annual per capita mushroom was 3.9 kg ('13), whichis a little higher than that in Europe. Thus, mushroom export, mainly Flammulina velutipes and Pleurotus ostreatus, has increased since the mid-2000s. Recently, however, it is slightly reduced. Nevertheless, Vietnam, Hong Kong, the United States, and the Netherlands continue to export mushrooms, and Korea has increased its export to Australia, Canada, Southeast Asia, etc. Canned Agaricus bisporus, the first export of the Korean mushroom industry, reached it speak sales in 1977-1978. When Korea initiated trade with China in 1980, the international prices of mushrooms fell sharply, leading to shrinkage of the domestic markets. Spurred by the high demand to develop substitute goods for A. bisporus, the oyster mushroom (P. ostreatus) gained attention since it seemed to suit the taste of Korean consumers. Although the log cultivation technique for oyster mushroom was developed in the early 1970s, it required a great deal of labor. Thus, we developed the shelf cultivation technique, which is easier to manage and allows for mass production. In this technique, the growing shelf is made mafrom fermented rice straw, whichis the only P. ostreatus medium in the world and isused only in South Korea. After then, the use of cotton wastes as an additional material of medium, the productivity. Currently, we are developing a standard cultivation technique and environmental control system that can stably produce mushrooms throughout the year. The increase of oyster mushroom production may boostthe domestic market and contribute to industrial development. In addition, oyster mushroom production technology played a role in forming the basis for the development of bottle cultivation, which made mass production. In particular, bottle cultivation using liquid spawn could allow for the export of F. velutipes and Pleurotus eryngii. In addition, the white varieties of F. velutipes were second developed in the world after Japan. We also developed the new A. bisporus cultivar 'Saeah', which is easy to grow in Korea. In hopes to advance the mushroom industry, we will continue to develop cultivars with international competitive power and to improve cultivation techniques.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.33 no.3
• /
• pp.298-308
• /
• 1988

This study was carried out to get infirmation for the breeding varieties and developing the cultural methods with representative 32 cultivars which were diffused from 1900 to 1982 and two cultural methods which were old one i.e., low dressing and late planting and modern one i.e., medium dressing and early planting. Duration of transplanting between cultural practices were 15 days but the duration of heading date were 5days. Panicle projecting duration was 5-10 days in all cultivars, especially, it is 5 days in early maturing varieties, 6-7 days in medium maturing varieties and 7-10 days in late maturing varieties. Periods from transplanting date to effective ripening date were 99.8 days in low dressing and late planting method, 106.2 days in modern one but the periods from heading date to effective ripening date were 31.4 days in low dressing and late planting method, 30.2 days in modern one. Ripening speed was very active from 5 to 10 days after heading and the daily increase of 1000 grain weight was from 847.8mg to 1130mg in that time and it slightly increased from 5 to 35 days after heading in Japonica varieties but increased after heading and suddenly decreased at 30 days after heading in Indica/Japonica varieties. Meteorological factors (temperature and amount of solar radiation) were positively correlated with the ripening speed but negatively correlated with the period of physiological and effentive ripening.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.33 no.3
• /
• pp.309-314
• /
• 1988

This study was carried out to get information for the breeding varieties and developing the cultural methods with representative 32 cultivars which were diffused from 1900 to 1982 and two cultural methods which were old one i.e., low dressing and late planting and modern one i.e., medium dressing and early planting. Duration of transplanting between cultural practices were 15 days but the duration of heading date were 5 days. Panicle projecting duration was 5-10 days in all cultivars, especially, it is 5 days in early maturing varieties, 6-7 days in medium maturing varieties and 7-10 days in late maturing varieties. Periods from transplanting date to effective ripening date were 99.8 days in low dressing and late planting method, 106.2 days in modern one but the periods from heading date to effective ripening date were 31.4 days in low dressing and late planting method, 30.2 days in modern one. Ripening speed was very active from 5 to 10 days after heading and the daily increase of 1000 grain weight was from 847.8mg to 1130mg in that time and it slightly increased from 5 to 35 days after heading in japonica varieties but increased after heading and suddenly decreased at 30 days after heading in Indica/Japonica varieties. Meteorological factors (temperature and amount of solar radiation) were positively correlated with the ripening speed but negatively correlated with the period of physiological and effective ripening.