• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.611-617
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• 2010

The current studies aim is to analyze the production cost of walnut tree cultivation and its object was targeted at walnut tree cultivating household region 163. The analysis is as follows. Our domestic walnut tree cultivating households averagely have cultivated about 0.7ha, and planting number per ha was averagely 204, and it showed that compared to the standard planting number (100), the plantation was done close planted. The most cultivar cultivated according to regions were Chungbuk region: sangchon 65.7%, Chungnam region: kwangduk 68.6%, Jeonbuk region: sangchon 98.0%, Gyeongbuk region: daeboo 61.2%. The production cost for cultivating walnuts can be classified into the followings; management cost(4436 thousand won/ha) such as manufacturing cost(292 thousand won/ha), intermediate material cost(3682 thousand won/ha), rent(103 thousand won/ha), employment cost(653 thousand won/ha) etc, and self-serviced expenses such as self-laboring cost(5,834 thousand won/ha), land security cost(490 thousand won/ha), fixed capital cost(834 thousand won/ha), circulating capital cost(234 thousand won/ha) etc. 11,820 thousand won were invested for the production cost of walnut and it made 11,586 thousand won/ha(rate of investment 72.3%) profit, and the net income was 4,196 thousand won/ha(net income rate 26.2%), showing high amount of income. The manufactured walnuts were marketed in Nong-hyup 39.8%, wholesalers 20.8%, dealers 19.8% and recently, as the amount of goods marketed directly to consumers themselves have increased, the income has reached up to 18.9%. At the basis of making most of idle soil, walnut tree's cultivated regions are fairly small, and due to the characteristics of sideline management, it has its limits in searching for production policy locally and promotion strategy of industries. Therefore, if the basic database can be established, subjected only to full-time cultivating households, then not only would the differences between the imported walnuts be reinforced, it would also be possible to transfer into the new and improved distribution system. Furthermore, through establishment of the database, it can be anticipated that it would contribute greatly in the increase of the household income.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.4
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• pp.304-310
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• 1981

In order to observe the degree and response of drought-resistance and its physiological mechanism in barley and wheat, 5 species (16 cultivars) were tested for changes in plant height, seedling dry weight, chlorophyll content, leaf relative turgidity, soluble protein, reducing sugar and growth of seedling subjected to water stress by withholding watering for 8 days at 10 days (at the 3rd leaf stage) after emergence. The average rate of decrease of all cultivars was 15% in plant height, 24% in seedling dry weight, 32% in chlorophyll content, 27% in leaf relative turgidity, and 27% in protein. But reducing sugar content of control was increased 4 folds more than that of water stress. In the decreased rate of seedling dry weight of each cultivar, rye was shown to be lowest rate, and Baegdong, Mokpo #55, and 3 two-row barley were shown to be the highest rate. The degree of the decreased rate in 5 species was in the order of rye < < wheat < covered barley < naked barley < two-row barley. in the decreased rate of chlorophyll content, rye, Cheonggaemil and Olmil are the lowest group, and the highest one are Milyang #12, Bangsa #6, Hyangmaeg and Sacheon #4. In the decreased rate of leaf relative turgidity, the lowest group (22-25%) were rye, Cheonggaemil and Dongbori #1, and, on the other hand, the highest group (30-33%) were Baegdong and 3 two-row barley. In the decreased rate of soulble protein, the lowest group (14-17%) were Chogwang, Geurumil, Dongbori #1, and Mokpo #55, and the highest one was 3 two-row barley. The increased ratio of reducing sugar of water stress to control was 4 to 5 folds in rye and wheat, and about 2 folds in naked barley and 3 two-row barley. The degree of the increased ratio of 5 species was in the order of rye > wheat > covered barley > naked barley > two-row barley. In terms of the physiological and adaptive metabolism during the processing leading to drought-resistance, the degree of drought-resistance of 5 species to water stress at seedling stage was shown to be in the order of rye > wheat > covered barley > naked barley > two-row-barley.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.2
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• pp.113-118
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• 2016

This experiment was conducted to identify the variations in inorganic nutrients and plant growth in millet (Panicum miliaceum L.) due to soil salinity. The soil series was Munpo and soil texture was silt loam. The experimental soil was amended so that the soil had salinities of $0.8dS\;m^{-1}$, $1.6dS\;m^{-1}$, $3.2dS\;m^{-1}$ and $4.8dS\;m^{-1}$. Millet was transplanted 15 days after sowing. As soil salinity increased, the degree of reduced growth was in the order of seed production > root dry matter > plant dry matter > culm length > tiller number > stem thickness > Panicle length. Seed production was decreased to 18.9% in soil salinity of $1.6dS\;m^{-1}$, 36.9% in of $3.2dS\;m^{-1}$, and 50.7% in EC of $4.8dS\;m^{-1}$. Root dry matter decreased to 35.8% in EC of $3.2dS\;m^{-1}$, and to 40.5% in EC of $4.8dS\;m^{-1}$. As soil salinity increased, Total nitrogen content increased in all aboveground parts, roots and seeds. However, There was no difference in CaO, $P_2O_5$, $K_2O$ and, MgO in soils of different salinity. On the other hand, $Na_2O$ content was higher in the order roots> shoots> seed, and in the case of roots, $Na_2O$ content increased to 1.02% in soil salinity of $4.8dS\;m^{-1}$. However, up to soil salinity of $1.6dS\;m^{-1}$, the $Na_2O$ content of the seed was similar to that in plant grown in the Control conditions($0.8dS\;m^{-1}$). In conclusion, taking into consideration economic factors, millet could be cultivated in soil with salinities of up to approximately $1.6dS\;m^{-1}$, and seed produced from reclaimedland would be suitable for human consumption.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.98-104
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• 2010

Excess nitrogen (N) uptake of rice, which could cause much lodging, disease and reduction of rice quality, could be occurred at the paddy field with previous upland condition at which much soil N could be mineralized by soil-drying effect. N fertilizers of 0, 3, and 6 kg N $10a^{-1}$ were applied to early-maturity rice, cultivar Joanbyeo at the paddy field of first and second year after upland condition, and rice growth and nitrogen uptake were investigated to know the increase of rice N uptake at the paddy field with previous upland condition for one-year. Total dry matter (DM) and N uptake of rice at the paddy field with previous upland condition increased more than continuous paddy field. Total DM and N uptake of rice at the paddy field with previous upland condition increased linearly to N fertilizer 6 kg $10a^{-1}$ at the paddy field owing to vigorous growth compared to continuous paddy field. Rice N uptake was higher at the paddy field of the first year than the second year after upland condition in considering N uptake at the plot of no N fertilizer. Vigorous growth at the paddy field with previous upland condition resulted in higher rice yield which was related with high panicle and spikelet, but much N fertilizer as much as 6 kg $10a^{-1}$ at the paddy field with previous upland condition resulted in higher lodging and protein content of brown and milled rice. Particularly, protein content of brown and milled rice increased more when the same N fertilizer was applied two times splitly at transplanting and panicle initiation stage than when N fertilizer was applied one time at transplanting as basal N. N application with under 3 kg $10a^{-1}$ as only basal N was recommended at the paddy field with previous upland condition to obtain high quality rice without lodging.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.304-310
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• 2017

This study was conducted over a 3-year period from 2013 to 2015 in the mid-northern inland, Cheolweon, Korea, to investigate changes in flowering date, daily mean temperature during grain filling, and yield characteristics affected by transplanting date in an early-maturing rice variety, 'Joun'. Thirty-day-old seedlings were transplanted at four different dates at 15-day interval from May 5 to June 19. Flowering dates were July 16, July 21, July 31, and August 14 when transplanting was performed on May 5, May 20, June 4, and June 19, respectively. Late transplanting resulted in higher daily mean temperature before flowering but late-transplanted rice required fewer days and lower cumulative temperature to reach flowering from transplanting. As transplanting was delayed, daily mean temperature for 40 days after flowering decreased, whereas daily sunshine hours for the same period increased, with a temperature of $24.8^{\circ}C$ and sunshine for 5.8 hours being recorded at the transplanting on May 5, and with a temperature of $21.0^{\circ}C$ and sunshine for 7.7 hours at the transplanting on June 19. With late transplanting, panicles per square meter significantly decreased, whereas spikelets per panicle showed an increasing trend. Regression analysis showed that maximum head rice yield was attained from the transplanting on May 18, for which the flowering date was July 21, and daily mean temperature for 40 days from that flowering date was $24.6^{\circ}C$. A decrease in head rice yield by 5% and 10% of the maximum was observed for rice transplanted on June 6 and June 15, which resulted in flowering dates of August 2 and August 11, respectively, and the daily mean temperatures for 40 days from flowering were 23.2 and $21.7^{\circ}C$, respectively. Therefore, in mid-northern inland, it is recommended to transplant 'Joun' on May 18 to induce flowering on July 21, when grain filling is subjected to a daily mean temperature of $24.6^{\circ}C$ during active filling stage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.275-284
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• 2017

Rice quality should be considered as a primary consumer requirement. Regarding marketing, characteristics such as appearance, physicochemical properties, and palatability of brand rice are of high economic importance. Therefore, this study was conducted to select the optimal rice cultivars representing the commercial rice brands of Gyeongsangbuk-do province in Korea. Various rice grain quality components, grain appearance, several physicochemical properties of rice grain, and texture or palatability of cooked rice grains of ten cultivars (namely 'top quality rice') cultivated at three different locations, such as inland mountainous and southern plain areas of Gyeongsangbuk-do province in 2013~2014, were evaluated, and the obtained data was analyzed. 'Hiami' showed slightly higher protein contents and lower palatability of cooked rice than the other rice cultivars. Rice production and head rice yield produced at Gumi were the highest. The protein content of milled rice produced at Andong, an inland mountainous region, was approximately 0.3% point lower than that from other locations, whereas the amylose content of milled rice was approximately 1% point higher than those from the other plain regions, Daegu and Gumi. We evaluated the texture, Glossiness value determined using a Toyo teste meter and palatability of cooked rice of ten cultivars. The hardness of cooked rice produced in Andong was slightly lower than that produced in Daegu and Gumi, and additionally, the palatability of cooked rice produced in Andong was the best, followed by that producted in Gumi and Daegu. Considering rice yield and grain quality in the major rice cultivation areas of Gyeongsangbuk-do province, the rice cultivars that may be suitable for each region could be recommended mid-late maturation: 'Younghojinmi' and 'Mipum' in Daegu, 'Daebo', 'Samgwang', Chilbo' and 'Younghojinmi' in Gumi, 'Samgwang', 'Jinsumi' and 'Sukwang' in Andong. These results obtained in this study imply that the selected cultivars with high yield and quality could be recommended with high priority to rice farmers in the regions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.4
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• pp.395-405
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• 2019

A recent assessment by the Intergovernmental Panel on Climate Change projected that the global average surface temperature will increase by a value 1.5℃ from 2030 to 2052. In this study, we used a temperature gradient chamber that mimicked field conditions to evaluate the effect of increased air temperature on phenology, yield components, protein content, and oil content, to assess soybean growth. In 2017 and 2018, 'Deawonkong', 'Pungsannamulkong', and 'Deapungkong' cultivars were grown in three temperature gradient chambers. Four temperature treatment groups were established by dividing the rows along temperature regimes: ambient temperature + 1℃ (aT+1), ambient temperature + 2℃ (aT+2), ambient temperature + 3℃ (aT+3), ambient temperature + 4℃ (aT+4). Year, cultivar, and temperature treatments significantly affected yield components and seed yield. In 2017, the flowering stage of 'Deawon' and 'Pungsannamul' cultivars in the aT+4 group was delayed compared to the flowering stage of those in the aT+1 group. In 2018, the flowering stage of 'Deawon' and 'Pungsannamul' was delayed at all temperature gradients, owing to high temperature stress, whereas 'Deapung' was regularly flowering in 2017 and 2018. The duration of the grain filling period was six days shorter in 2018 than in 2017 because of high temperature stress. The total number of pods per ㎡ for 'Deawon' and 'Pungsannamul' was 48.8 and 41.5% lower in 2018 than in 2017, respectively, whereas 'Deapung' increased by 6.3%. The 100-seed weight of 'Deawon' and 'Deapung' was 29.2 and 32.1% lower, respectively. However, 'Pungsannamul' decreased by 14.7%. The protein and oil content was lower during the grain filling period in 2018 than in the same period in 2017 because of high temperature stress. In contrast, the oil content in 'Deapung' was higher in 2018 than in 2017. Our results showed that increased temperature during the grain filling period was significantly and negatively correlated with pod number, 100-seed weight, protein content, and oil content.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.4
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• pp.344-352
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• 2019

Drought stress caused by global climate change is a serious problem for rice cultivation. Increasingly frequent abnormal weather occurrences could include severe drought, which could cause water stress to rice during the seedling stage. This experiment was conducted to clarify the effects of drought during the seedling period on yield and quality of rice. Drought conditions were created in a rain shelter house facility. The drought treatment was conducted at 3, 10, and 20 days after transplanting. Soil water content was measured by a soil moisture sensor during the whole growth stage. In this study, we have chosen 3 rice cultivars which are widely cultivated in Korea: 'Haedamssal' (Early maturing), 'Samkwang' (Medium maturing), and 'Saenuri' (Mid-late maturing). The decrease in yield due to drought treatment was most severe 3 days after transplanting because of the decrease in the number of effective tillers. The decrease in grain quality due to drought treatment was also most severe 3 days after transplanting because of the increased protein content and hardness of the grains. The cultivar 'Haedamssal' was the most severely damaged by water stress, resulting in about a 30% yield loss. Drought conditions diminished the early vigorous growth period and days to heading in early-maturing cultivars. The results show that drought stress affects yield components immediately after transplanting, which is a decisive factor in reducing yield and grain quality. This study can be used as basic data to calculate damage compensation for drought damage on actual rice farms.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.4
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• pp.323-335
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• 2019

Rice is sensitive to day-length and short-day plants. It has a characteristic that the photosensitivity response required for flower bud differentiation decreases under long-day conditions. To identify critical photoperiod required for flower bud differentiation of major cultivation rice varieties, the average temperature was fixed at 28 ℃, and the day length was set at 12 hours and 10 minutes intervals from 13 hours to 14 hours 30 minutes. The critical photoperiod for each cultivar was set to day-length, where the daily cumulative response [(X_{(Critical Photoperiod)}-Y_{(Set day-length)})/(X_{(Critical Photoperiod)}-12:00_{(Optimal Day-length)}) × (28.0_{(Set Temperature)}-10_{(Minimum Temperature)})/(29.2_{(Maximum Temperature)}-10_{(Minimum Temperature)})] was the same for each day-length conditions. The flower bud differentiation time of all varieties was 32 days before heading at the average temperature of 28 ℃ conditions. The critical photoperiod of the early maturing type, such as Woonkwang, Odae, Koshihikari, Jopyeong, were 19:20, 18:14, 18:58, 17:30, respectively. Medium maturing type, such as Daebo, Haiami, Samdeok, were 16:08, 16:15, 16:55, respectively. Mid-late maturing type, such as Saenuri, Sindongjin, Chucheong, Samkwang, Ilpum, Saeilmi, Hwangkeumnuri, Dongjinchal, Ilmi, Hopum, Yeonghojinmi, were 15:58, 15:56, 16:36, 16:44, 15:35, 16:26, 15:33, 16:20, 16:29, 16:13, 15:41.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.4
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• pp.414-421
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• 2019

Pod shattering during the maturing stage causes a serious yield loss in soybean. It is the main limiting factor of soybean cultivation and mechanization. It is important to develop varieties suitable for mechanical harvesting and to develop energy-efficient agricultural machinery to save labor and costs. 'Daewonkong,' developed by the National Institute of Crop Science (NICS) in 1997, is an elite cultivar that occupies more than 80% of the soybean cultivation area in Korea because of its strong tolerance to pod shattering. The objectives of this study were to investigate the variation in pod shattering degree in a RIL population developed from a 'Daewonkong' parent and to select promising lines with pod shattering tolerance. 'Daewonkong' demonstrated a high level of tolerance to pod shattering compared to the 'Tawonkong' and 'Saeolkong' varieties, with no shattered pods after 72 hours of drying. Screening of pod shattering showed a clear distinction between the tolerant and susceptible varieties. Also, the distribution of shattering pod ratio in the two populations showed a similar pattern for three years. The promising lines with pod shattering tolerance included 27 lines in the 'Daewonkong'×'Tawonkong' population and 21 lines in the 'Daewonkong'×'Saeolkong' population. The promising lines are expected to be widely used as breeding parents for creating soybean cultivars with pod shattering tolerance.