• Korean Journal of Medicinal Crop Science
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• v.4 no.1
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• pp.52-57
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• 1996

This study was carried out to compare isozyme band pattern, growth characteristics and tuber yield of Dioscorea batatas to get basic information for varietal classification. It could be identify clearly by protein and esterase band pattern of leaf, petiole and stem tissue in three cultivar but with peroxidase band it was difficult to identify because of similar pattern in leaf and petiole tissue. Three cultivars has different leaf shape as Dan-ma and Jang-ma were lanceolate, Sukunea was long-heart shape in upper part of plants. In phyllotaxis, Dan-ma and Jang-ma shows alternate and opposite but Suwon 2 shows opposite in upper parts of stem. Root length shows significant difference from 9.7cm to 51cm respectively as 30cm, 51cm and 9.7cm in Dan-ma, Jang-ma and Sukunea. Tuber yield of three cultivars were 27.5M/T in Dan-ma, 22.8M/T in Jang-ma and 22.8M/T/ha in Sukunea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.4
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• pp.378-383
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• 2018

The goal of this study was to examine the growth and yield according to planting density in wide-row drill seeding cultivation suitable for mechanized harvesting. We evaluated effects depending on planting densities [row spacing (30, 40, 50, and 60 cm) and plant spacing (10, 15, and 20 cm)] and cultivars ('Hongeon' and 'Arari') on growth and yield of Adzuki Beans (Vigna angularis (Willd.) Ohwi Ohashi). When row spacing decreased, the stem length increased in 'Arari' but decreased in 'Hongeon.' The stem diameter and number of branches in both the cultivars decreased with a decrease in row spacing. The pod height increased with lower planting densities. The greatest height values recorded in 'Hongeon' and 'Arari' were 5.0 cm and 8.8 cm in $30{\times}10cm$ and $50{\times}10cm$ treatments, respectively. The number of pods and number of seeds in both cultivars tended to increase with a decrease in planting density. On the other hand, in 100-seed weight, there was a difference in planting density in 'Hongeon', but no difference in 'Arari'. The highest yield was at the planting density of $40{\times}15cm$ in both 'Hongeon' and 'Arari', $285kg{\cdot}10a^{-1}$ and $374kg{\cdot}10a^{-1}$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.1
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• pp.33-39
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• 2019

The goal of this study was to investigate how the characteristics of growth and yield are affected by various planting densities in wide-row drill seeding cultivation suitable for mechanized harvesting. Two cultivars ('Hwanggeum' and 'Leebackchal') of proso millet (Panicum miliaceum L.) were planted at varying planting densities [row spacing (20, 30, and 50 cm) and plant spacing (3, 5, 10, and 15 cm)]. The culm length was highest at the planting density of $50{\times}3cm$ and $50{\times}5cm$ for 'Hwanggeum' and $20{\times}3cm$ for 'Leebackchal'. The culm diameter became thinner as the planting density increased. The number of tillering and panicle length showed the same tendency to increase in quantity or length as planting density decreased and was highest at $50{\times}15cm$ when the planting density was lowest. The number of seeds per individual increased as planting density decreased. The thousand grain weight showed no significant differences among treatment plots. The greatest yield of 'Hwanggeum' was obtained at a planting density of $50{\times}3cm$ ($314.9kg{\cdot}10a^{-1}$) and that of 'Leebackchal' was obtained at $50{\times}3cm$ and $50{\times}5cm$ ($358-356kg{\cdot}10a^{-1}$).

• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.1-7
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• 2022

Strawberry is a stand-out cultivating fruit in Korea. The optimum production of strawberry is highly dependent on growing environment. Smart farm technology, and automatic monitoring and control system maintain a favorable environment for strawberry growth in greenhouses, as well as play an important role to improve production. Moreover, physiological parameters of strawberry plant and it is surrounding environment may allow to give an idea on production of strawberry. Therefore, this study intends to build a machine learning model to predict strawberry's yield, cultivated in greenhouse. The environmental parameter like as temperature, humidity and CO₂ and physiological parameters such as length of leaves, number of flowers and fruits and chlorophyll content of 'Seolhyang' (widely growing strawberry cultivar in Korea) were collected from three strawberry greenhouses located in Sacheon of Gyeongsangnam-do during the period of 2019-2020. A predictive model, Lasso regression was designed and validated through 5-fold cross-validation. The current study found that performance of the Lasso regression model is good to predict the number of flowers and fruits, when the MAPE value are 0.511 and 0.488, respectively during the model validation. Overall, the present study demonstrates that using AI based regression model may be convenient for farms and agricultural companies to predict yield of crops with fewer input attributes.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.4
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• pp.258-263
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• 2022

This experiment was conducted to confirm the possibility of manufacturing artificial Italian ryegrass hay using far-infrared rays in Korea. The machine used in this experiment was a far-infrared ray dryer capable of adjusting temperature, airflow, and far-infrared radiation, and was conducted on Italian ryegrass harvested in May. Conditions for drying were performed by selecting a total of nine conditions, and each condition was set to emission rate of 42 to 45%, and the internal temperature was set to 65℃. The speed of the air flow in the machine was 40-60 m/s, and the overall drying time was 30 minutes for 42% radiation, 25 minutes for 43% radiation, and 20 minutes for 45% radiation. The final dry matter content according to each drying condition was 88.5% on average, and the dry matter content suitable for hay was shown in the all treatment. Looking at the power consumption according to the drying conditions, the lowest was found in the treatment that dried for 20 minutes at 45% radiation. In the drying rate, there was no difference in drying conditions 1 to 5, but a significantly low tendency was shown in conditions 6 to 7. In terms of feed value, CP and IVDMD were higher than raw materials in most drying conditions, and ADF and NDF contents were low, and tended to be high in drying conditions 4, 7, and 8. Through the above results, it was judged that drying conditions 7 and 8 were the most advantageous when considering drying speed, power consumption, and quality.

• Journal of Practical Agriculture & Fisheries Research
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• v.25 no.2
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• pp.5-11
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• 2023

Rehmannia glutinosa is a perennial herb belonging to the family Scrophulariaceae and is used in traditional oriental medicine. This study was carried out current status of breeding of R. glutinosa, its problems, and the matters to be improved were made. Based on the research data published so far, this study summarized the characteristics of breeds cultivated in Korea and compared and analyzed the status of cultivation area, production, import, and price changes for 15 years from 2008 to 2021. The cultivated area of R. glutinosa is gradually decreasing, and the amount of import is increasing and decreasing repeatedly. Amount of import has declined significantly. There was a lot of disinfection and disposal in the middle of import, and dried Jihwang and Sukjihwang were imported without distinction. R. glutinosa must be cultivated and supplied as a variety desired by the industry, cultivation techniques need to be taught to producers. In order to clearly identify the amount of import, import code of dried Jihwang and Sukjihwang must be classify. In addition, it is necessary to develop and supply harvesting agricultural machines for mechanization. For the stable income of producers, supply control through contract cultivation will ensure stable farm income.

• Food Science and Preservation
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• v.30 no.6
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• pp.983-990
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• 2023

This study was conducted to develop a preservation technology that can induce changes in physicochemical properties to effectively utilize of persimmon leaves. The application effects of steaming or freezing technique were investigated. Astringent persimmon leaves were steam-blanched (100℃, 30 sec) or frozen (-20℃, 15 d), followed by hot-air drying (50℃). The physicochemical properties of the extract obtained by hot-water leaching from the dried leaves were compared. The extract of leaves dried without pretreatment was used as a control. L* value was higher in steamed than in control and frozen. a* value was highest in the control. The browning index was higher in the frozen and lower in the steamed than in the control. Soluble solids were the highest in the steamed and the lowest in the frozen. Sucrose content was relatively high in the steamed, and the glucose and fructose contents were relatively high in the frozen. Total polyphenol content and DPPH radical scavenging activity were higher in steamed and lower in frozen than in control. Thus, it was confirmed that steam or freeze pretreatment after harvesting persimmon leaves affects the extraction yield, color, antioxidant capacity and component changes of dried persimmon leaves. Unlike steaming, freezing pretreatment showed the effect of promoting decomposition and browning reactions, and it is considered useful when such an effect is needed.

• Korean Journal of Agricultural Science
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• v.13 no.1
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• pp.113-122
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• 1986

In order to promote mechanization of corn harvesting in Korea, this study was conducted to find out the effect of moisture content on compressive properties such as force, deformation, energy and modulus of stiffness to the bioyield and the rupture point for Korean corn kernel. In this study, the loading positions of corn were flat, edge, longitude and the moisture contents were about 13, 17, 21, 25% in wet basis. The compression test was carreied out with flat plate by use of dynamic straingage for three varieties of Korean corn under quasi-static force when the loading rate was 1.125mm/min. The results of this study are summarized as follows; 1. When the moisture content of corn ranged from 12.5 to 24.5 percent, at flat position, the bioyied force was in the range of 13.63-26.73 kg and the maximum compressive strength was in the range of 21.55-47.65kg. Their values were reached minimum at about 17% and maximum at about 21% moisture content. The bioyield force was in the range of 13.58-6.70kg at edge position and the maximum compressive strength which was 16.42 to 7.82kg at edge position was lower than that which was 18.55-9.05kg at longitudinal position. 2. Deformation of corn varied from 0.43 to 1.37 mm at bioyield point and from 0.70 to 2.66mm at rupture point between 12.5 to 24.5% moisture content. As the moisture content increased, deformation was increased. 3. The moduli of resilience and toughness of corn ranged from 2.60 to 8.57kg. mm and from 6.41 to 34.36kg. mm when the moisture content ranged from 12.5 to 24.5 percent, respectively. As the moisture content increased, the modulus of toughness was increased at edge position and decreased at longitudinal position. And their values were equal each other at 22-23% moisture content. 4. The modulus of stiffness was decreased with increase in the moisture content. Its values ranged from 32.07 to 5.86 kg/mm at edge position and from 42.12 to 18.68kg/mm at flat position, respectively. Also, the values of Suweon 19 were higher than those of Buyeo. 5. It was considered that the compressive properties of corn at flat position were more important on the design data for corn harvesting and processing machinery than those of edge or longitudinal position. Also, grinding energy would be minimized when a corn was processed between about 12.5 to 17% moisture content and corn damage would be reduced when a corn was handled between about 19 to 24% moisture content in wet basis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.3
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• pp.301-309
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• 2012

This study was performed to compare the properties affecting the palatability of 33 commercial brands of rice. Five rice varieties were identified including Chucheongbyeo, Hitomebore, Ilpumbyeo, Nampyeongbyeo, Seachucheongbyeo, were compared in terms of physicochemical characteristics, texture, head riceratio, and palatability through Toyo values. We also analyzed the relationship between grain characteristics and palatability. Amylose content of 5 rice varieties ranged from 17.04-17.98%. Nampyeongbyeo had the lowest and Seachucheongbyeo had the highest content of amylose among rice varieties. The protein content of 5 varieties ranged from 6.72-7.55%. Nampyeongbyeo showed the highest content. The moisture content varied from 13.08-14.83%. Chucheongbyeo has the highest moisture content. The head rice ratio of Ilpumbyeo, Chucheongbyeo, and Seachucheongbyeo were over the 90%, which was lower than that of Japan. Chucheongbyeo had the lowest hardness value and the highest adhesiveness value as measured by texture analyzer. The palatability value was highest in Chucheongbyeo, and the lowest in both Nampyeongbyeo and Ilpumbyeo. The palatability value was negatively correlated with protein content, but positively correlated with texture, moisture content, and head rice ratio. Based on this results, the rice varieties with high palatability had lower contents of amylose and protein, but higher moisture content and head rice ratio. Chucheongbyeo seemed to be the valuable variety with the highest palatability among them.

• Journal of the Korean association of regional geographers
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• v.2 no.1
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• pp.51-67
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• 1996

There are three main rice-growing regions in the United States: the prairie region along the Mississippi River Valley in eastern Arkansas; the Gulf Coast prairie region in southwestern Louisiana and southeastern Texas; and the Central Valley of California. The Central Valley of California is producing about 23% of the US rice(Fig. 1). In California. most of the crop has been produced in the Colusa, Sutter, Butte, Glenn Counties of the Sacramento Valley since 1912, when rice was commercially grown for the first time in the state(Fig. 2). Roughly speaking, the average annual area sown to rice in California is about 300,000 acres to 400,000 acres during the last forty years(Fig. 3). California rice is grown under a Mediterranean climate characterized by warm, dry, clear days, and a long growing season favorable to high photosynthetic rates and high rice yields. The average rice yield per acre is probably higher in California than in any other rice-growing regions of the world(Fig. 4). A dependable supply of irrigation water must be available for a successful rice culture. Most of the irrigation water for California rice comes from the winter rain and snow-fed reservoir of the Sierra Nevada mountain ranges. Less than 10 percent of rice irrigation water is pumped from wells in areas where surface water is not sufficient. It is also essential to have good surface drainage if maximum yields are to be produced. Rice production in California is highly mechanized, requiring only about four hours of labor per acre. Mechanization of rice culture in California includes laser-leveler technology, large tractors, self-propelled combines for harvesting, and aircraft for seeding, pest control, and some fertilization. The principal varieties grown in California are medium-grain japonica types with origins from the cooler rice climates of the northern latitudes (Table 1). Long-grain varieties grown in the American South are not well adapted to California's cooler environment. Nearly all the rice grown recently in California are improved into semidwarf varieties. Choice of variety depends on environment, planting date, quality desired, marketing, and harvesting scheduling. The Rice Experiment Station at Biggs is owned, financed, and administered by the rice industry. The station was established in 1912, as a direct result of the foresight and effort of Charles Edward Chambliss of the United States Department of Agriculture. Now, The station's major effort is the development of improved rice varieties for California.