• Korean Journal of Plant Resources
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• v.18 no.1
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• pp.179-185
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• 2005

This study was conducted to evaluate the major agronomic characteristics Korean of 85 and Chinese Jilim Province of 5 local varieties of perilla at Chungbuk Agricultural Research and Extension Services in 2001. Perilla accessions examined were classified into three maturity groups, i.e, early, medium, and late maturity group of $19\;(23\%),\;57\;(67\%)$, and $9\;(10\%)$ accessions, respectively. The early and late maturity groups mainly consisted of collections from middle-northern area and southern area, respectively, while the medium group consisted of accessions from all over the country. But chinese Jilim collection wad all mediumgroup. Average 1,000-seed weight(TSW) was 2.7 g. TSW of the collection from Hamyang was the greatest a 3.9g, while the TSW of Pyungchang collection was the smallest as 1.7g, and most of collections produced medium and small seeds. Perilla accessions with greate 1,000-seed weight seemed to be belonged to the late maturity group. Chinese collection was 2.2 to 3.19g and overage was 2.6g in average. Accodingly TSW hadn't more variegation than Korean. Seed coat colors of gorilla accessions were dark brown$(30\%)$, brown$(55\%)$ and gray brown$(6\%)$, respectively. Among seed coat colors, brown color consisted of $91\%$. Chinese was dark brown$(20\%)$, brown$(80\%)$ in color. Positively correlated that stem height, the number of nodes, branches and flower clusters with Korean and Chinese collection, capsules per flower cluster and the length of flower cluster with Korean collection and 1,000-seed weight and maturing period, flower clusters, stem height and the number of nodes with Chinese collection. And negatively correlated that the number of capsules per flower cluster and 1,000-seed weight with Korean collection and the length of flower cluster, stem height, branches, the number of nodes and flower clusters with Chinese collection.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.2
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• pp.30-37
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• 1964

Experiments were carried out to clarify the relationships between seed yields and some ecological characteristics, seed yields and some morphological characteristics, and the relationships among the varietal yields on the several sowing plots when grown under different climatic conditions. Twenty-four soybean varieties were used as the material, selected at random from 138 varieties which were cultivated the year before. These varieties were grown in the Experimental Farm, Chinju Agricultural College, Kyung Sang Namdo, Korea, and seed sowing was conducted at 5 times, from April to July, in 1962 and 1963. The results obtained are summarized as follows: 1. Correlations between seed yields and some ecological characteristics on the sowing date bases are shown in Table 1. Among some ecological characteristics, it was observed that there wert close relationships between seed yields and days to flowering, and between seed yields and the total growing length, except on the late sowing, i.e. July sowing plots, However, there was no clear correlation between seed yields and durations of flowering, and between seed yields and days from flowering to maturity. 2. Correlations between seed yields and some morphological characteristics on the sowing date bases are shown in Table 2. From this table, it was also observed that there were some close relationships between seed yields and branch number for plant, stem diameter, plant weight, pod number per plant, and grain number per plant, but there was no clear relationship between seed yields and stem length, and between seed yields and 100 grain weight, on every sowing plot. 3. Relations between varietal yields and the sowing dates are shown in Table 3. Our leading varieties such as Ulsan, Sangdoo, Changdan Backmok, Iksan, Haman, Barchongdeo, and Anion Daerip, which belong to the maturity groups of IV, V, and VI, have been significantly high in yield at each sowing date plot, but the extreme early varieties, that frequently are damaged by insects, moisture and diseases, and the extreme late varieties, that frequently are caught by frost suffering reduced yield, are showed a lower yield than the others. However, extreme early varieties, for instance, Black Hawk, an American variety, and Chung Buk Baek, a Korean early variety, showed high productivity on the late sowing, June and July sowing plots, and Do san No. 6, which is late Japanese variety, showed a high yield on the extreme early sowing, i.e. April sowing plots. 4. Relations between seed yields and the sowing dates on the varietal bases are shown in Table 4. It was observed that, the early varieties did not differ much in yields at the various sowing dates while the yields of late varieties decreased progressively with subsequent dates. However, the extreme late varieties, such as Tamanishiki, that frequently are caught by frost suffering reduced yield, may be difficult to harvest at this location. The results in these experiments showed that in most cases maximum yields were obtained when leading varieties, which are medium or late varieties, were shown in Mid-May, and progressively lower yields were produced from June and July sowings. On the other hand, the late sowings of the early varieties, such as Black Hawk and Chung Buk Baek, in these experiments showed favorable yields compared with the others. From these results, we can predict that our local medium or late varieties produce higher yields at this location than was produced by early varieties in most of the sowing dates, especially the May sowing, and early varieties such as Black Hawk and Chung Buk Baek should be used in the late sowing, June sowing time.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.2
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• pp.27-29
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• 1964

Experiments were carried out to clarify the relationships between seed yields and some ecological characteristics, seed yields and some morphological characteristics, and the relationships among the varietal yields on the several sowing plots when grown under different climatic conditions. Twenty-four soybean varieties were used as the material, selected at random from 138 varieties which were cultivated the year before. These varieties were grown in the Experimental Farm, Chinju Agricultural College, Kyung Sang Namdo, Korea, and seed sowing was conducted at 5 times, from April to July, in 1962 and 1963. The results obtained are summarized as follows: 1. Correlations between seed yields and some ecological characteristics on the sowing date bases are shown in Table 1. Among some ecological characteristics, it was observed that there wert close relationships between seed yields and days to flowering, and between seed yields and the total growing length, except on the late sowing, i.e. July sowing plots, However, there was no clear correlation between seed yields and durations of flowering, and between seed yields and days from flowering to maturity. 2. Correlations between seed yields and some morphological characteristics on the sowing date bases are shown in Table 2. From this table, it was also observed that there were some close relationships between seed yields and branch number for plant, stem diameter, plant weight, pod number per plant, and grain number per plant, but there was no clear relationship between seed yields and stem length, and between seed yields and 100 grain weight, on every sowing plot. 3. Relations between varietal yields and the sowing dates are shown in Table 3. Our leading varieties such as Ulsan, Sangdoo, Changdan Backmok, Iksan, Haman, Barchongdeo, and Anion Daerip, which belong to the maturity groups of IV, V, and VI, have been significantly high in yield at each sowing date plot, but the extreme early varieties, that frequently are damaged by insects, moisture and diseases, and the extreme late varieties, that frequently are caught by frost suffering reduced yield, are showed a lower yield than the others. However, extreme early varieties, for instance, Black Hawk, an American variety, and Chung Buk Baek, a Korean early variety, showed high productivity on the late sowing, June and July sowing plots, and Do san No. 6, which is late Japanese variety, showed a high yield on the extreme early sowing, i.e. April sowing plots. 4. Relations between seed yields and the sowing dates on the varietal bases are shown in Table 4. It was observed that, the early varieties did not differ much in yields at the various sowing dates while the yields of late varieties decreased progressively with subsequent dates. However, the extreme late varieties, such as Tamanishiki, that frequently are caught by frost suffering reduced yield, may be difficult to harvest at this location. The results in these experiments showed that in most cases maximum yields were obtained when leading varieties, which are medium or late varieties, were shown in Mid-May, and progressively lower yields were produced from June and July sowings. On the other hand, the late sowings of the early varieties, such as Black Hawk and Chung Buk Baek, in these experiments showed favorable yields compared with the others. From these results, we can predict that our local medium or late varieties produce higher yields at this location than was produced by early varieties in most of the sowing dates, especially the May sowing, and early varieties such as Black Hawk and Chung Buk Baek should be used in the late sowing, June sowing time.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.1
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• pp.31-37
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• 1993

To analyze and classify the varietal variation of alkali digestibility in detail, which is closely connected with the gelatinization temperature and physical characteristics of cooked rice, the patterns of alkali decomposition changed along the alkali concentration were investigated for thirty three Korean leading rice cultivars and new breeding lines(japonica : 25, Tongil-type:8) including five glutinous rice. Principal component analysis was used to condense the information and to classify rice materials according to decomposed reaction pattern at several levels of potassium hydroxide(KOH) concentration. Thirty three rice varieties were classified largely into four groups by the distribution on the plane of upper two principal component scores which contained above 92% of total informations. Group I was consisted of one variety, Dobongbyeo, which owned almost same strong resistance to alkali digestion at the range of 0.8% to 1.6% KOH solutions. Group II included three japonica and Tongil-type glutinous rice varieties, which revealed medium alkali digestion value(ADV) at 1.4% KOH solution and intermediate change in ADV from 0.8% to 1.6% KOH solutions. Most of Tongil-type and early-maturity japonica rice, which exhibited medium-high ADV at 1.4% of KOH concentration and large ADV difference between low and high alkali solutions, were contained in Group III. Group N included most of medium or medium-late-maturity japonica, which showed high ADV at 1.4% KOH and medium or intermediate-high ADV change between low and high alkali solutions. The 1st principal component indicated the average index of ADV through 0.8-1.6% KOH solutions and the 2nd principal component pointed out the factor related with ADV difference between low and high alkali solutions or regression coefficients of ADV change along with the KOH concentrations.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.2
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• pp.97-104
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• 2006

This experiment was carried out to determine the effect of harvesting date on the forage yield and quality of different rye (Secale cereale L.) cultivars. The experiment was conducted in split plot design with three replications. The main plots consisted of two harvesting dates 20th and 30th April. The subplots consisted of five rye cultivars from different maturity groups such as 'Kodiak (Late)'. 'Koolgrazer (Early)', 'Danko (Late)', 'Homil22 (Medium)' and 'Olhomil (Early)' Dry matter (DM) contents of 17.8% at early harvesting were lower 2.2% than at late harvesting. But crude protein (CP) of 18.9% and total digestible nutrients (TDN) contents of 65.5% at early harvesting were higher 2.3% and 3.0% than those at late harvesting, respectively. There were significant differences in DM, CP and TDN contents among the rye cultivars tested (p<0.05). The contents of fiber components at early harvesting were lower than those at late harvesting. The acid detergent fiber (ADF), neutral detergent fiber (NDF), cellulose and acid detergent lignin (ADL) contents at early harvesting were lower than those at late harvesting, and hemicellulose contents at early harvesting was higher than that at late harvesting. The fiber component of early maturing cultivars such as 'Koolgrazer' and 'Olhomil' were higher than those of the others. Dry matter, CP, in vitro digestible dry matter (IVDDM) and TDN yields at early harvesting were lower than those at late harvesting, and the yield of early maturing cultivars were higher than those of the others. In this study, the results of this study indicate that forage production technology in combination with early maturing rye cultivar and late harvesting could enhance both production and quality of rye.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.295-298
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• 2008

"Dongjin2" is a new japonica rice cultivar developed from the cross between Milyang165 with short culm and lodging resistance and $F_1$ plant of Iksan438, HR14018-B-1-1 and Iksan435 with high palatability at Honam Agricultural Research Institute (HARI), NICS, RDA in 2005. This cultivar has short grain shape and about 143 days growth duration from direct seeding to harvesting under Korean climate condition. The milled kernels of "Dongjin2" is translucent with non-glutinous endosperm. It has about 19.3% of amylose content and better palatability of cooked rice compared with "Nampyeongbyeo". This cultivar shows high resistance reaction to the bacterial blight pathogene race from $K_1$ to $K_3$, blast and stripe virus but susceptible to insect pests. "Dongjin2" yields about 5.71 and 5.74 MT/ha under the wet direct seeding and the transplanting at standard fertilizer level. "Dongjin2" would be adaptable for the southern plain area of Korea.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.1
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• pp.31-38
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• 2006

This experiment was carried out to determine the effects of different sowing dates and cultivars on the forage yield and quality of winter rye (Secale cereale L.). The experiment was conducted in a split plot design with three replications. The main plots consisted of two sowing dates such as early (15 September) and late (30 September). The subplots consisted of rye cultivars of five different maturity groups such as 'Kodiak' (Late), 'Koolgrazer' (Early), 'Danko' (Late), 'Homil22' (Medium) and 'Olhomi1' (Early). Dry matter (DM) content at early sowing (19.7%) was higher than those at late sowing (17.8%), while crude protein (CP) and total digestible nutrients (TDN) contents at early sowing (16.6% and 61.6%) were lower than those at late sowing (16.8% and 63.1%). Although DM content of early maturing cultivars (Koolgrazer and Olhomi1) was higher than the other cultivars, CP and TDN contents of those were lower compared to other cultivars. The contents of fiber components (ADF, NDF and cellulose) at early sowing were higher than those at late sowing, while ADL and hemicellulose at early sowing were lower than those at late sowing. ADF and cellulose of early maturing cultivars were higher than those of the other cultivars, while ADL and hemicellulose of Danko were higher than that of the other cultivars. DM, CP, In vitro dry matter digestibility (IVDMD) and TDN yields at early sowing were higher than those at late sowing, and early maturing cultivars were higher than those of the other cultivars. Results of this study indicate that forage production technology in combination with early sowing and use of early maturing rye cultivar could enhance both production and quality of rye.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.4
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• pp.327-337
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• 1996

A field experiment was conducted at SNU Experimental Livestock Farm, Suweon in 1995 to determine effect of planting date on forage performance of wm hybrids of four different maturity groups. A split-plot design replicated three times was used, with com hybrids representing four maturity groups (115, 118, 121 and 125 days) being the main plots and planting dates (3124, 415, 415, 425, 515 and 5/15) the sub-plots. 1. Days to emergence and percent emergence from the March 24 planting were, on the average, 36 days and 58%, respectively, but those from the April 5 to May 15 planting averaged 12 days and 92%, respectively. 2. Plant and ear heights increased gradually as the dates of planting were delayed except the May 15 planting, however, percent ear was decreased as the dates of planting were delayed. There was a trend for the mean lodging percentage of the hybrids to be higher as the planting date was delayed. 3. The 115-and 118-day mediumearly maturing hybrids harvested on August 18 produced silages with a dry matter content between 27 and 30% at all planting dates except the May 15 planting, while the 121-and 125-day medium-late maturing hybrids produced silages with a dry matter wntent less than 27% regardless of any planting dates. 4. There were no significant differences in mean dry matter yield among the hybrids, but significant mean TDN yield differences were found. The 115-, 118- and 125-day hybrids had significantly higher mean TDN yield than the 121-day hybrid. There were significant differences in mean dry matter and TDN yields among the planting dates. The mean dry matter and TDN yields from the April 5, 15 and 25 plantings were significantly higher than those of other plantings, however, there were no significant differences in mean TDN yield among the April 5, April 15 and April 25 plantings. No significant planting date $\times$ maturity interactions were found for both the dry matter and TDN yields. 5. Mean stover NDF and ADF contents of the 115- and 118day hybrids were higher than those of the 121- and 125-day hybrids, but the reverse was true for mean stover IVDMD and RFV. Mean stover NDF an ADF contents increased with earlier plantings, but mean stover IVDMD and RFV increased when planting was delayed. Results of this experiment indicate that for corn planting in central and northern areas of Korea, early to mid-April may be the right time with the 115-to 118-day maturity hybrids when silage making before August 20 is taken into consideration.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.2
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• pp.112-126
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• 1991

The atmospheric carbon dioxide concentration is ever-increasing and expected to reach about 600 ppmv some time during next century. Such an increase of $CO_2$ may cause a warming of the earth's surface of 1.5 to 4.5$^{\circ}C$, resulting in great changes in natural and agricultural ecosystems. The climatic scenario under doubled $CO_2$ projected by general circulation model of Goddard Institute for Space Studies(GISS) was adopted to evaluate the potential impact of climate change on agroclimatic resources, net primary productivity and rice productivity in Korea. The annual mean temperature was expected to rise by 3.5 to 4.$0^{\circ}C$ and the annual precipitation to vary by -5 to 20% as compared to current normal climate (1951 to 1980), resulting in the increase of possible duration of crop growth(days above 15$^{\circ}C$ in daily mean temperature) by 30 to 50 days and of effective accumulated temperature(EAT=∑Ti, Ti$\geq$1$0^{\circ}C$) by 1200 to 150$0^{\circ}C$. day which roughly corresponds to the shift of its isopleth northward by 300 to 400 km and by 600 to 700 m in altitude. The hydrological condition evaluated by radiative dryness index (RDI =Rn/ $\ell$P) is presumed to change slightly. The net primary productivity under the 2$\times$$CO_2$ climate was estimated to decrease by 3 to 4% when calculated without considering the photosynthesis stimulation due to $CO_2$ enrichment. Empirical crop-weather model was constructed for national rice yield prediction. The rice yields predicted by this model under 2 $\times$ $CO_2$ climatic scenario at the technological level of 1987 were lower by 34-43% than those under current normal climate. The parameters of MACROS, a dynamic simulation model from IRRI, were modified to simulate the growth and development of Korean rice cultivars under current and doubled $CO_2$ climatic condition. When simulated starting seedling emergence of May 10, the rice yield of Hwaseongbyeo(medium maturity) under 2 $\times$ $CO_2$ climate in Suwon showed 37% reduction compared to that under current normal climate. The yield reduction was ascribable mainly to the shortening of vegetative and ripening period due to accelerated development by higher temperature. Any simulated yields when shifted emergence date from April 10 to July 10 with Hwaseongbyeo (medium maturity) and Palgeum (late maturity) under 2 $\times$ $CO_2$ climate did not exceed the yield of Hwaseongbyeo simulated at seedling emergence on May 10 under current climate. The imaginary variety, having the same characteristics as those of Hwaseongbyeo except growth duration of 100 days from seedling emergence to heading, showed 4% increase in yield when simulated at seedling emergence on May 25 producing the highest yield. The simulation revealed that grain yields of rice increase to a greater extent under 2$\times$ $CO_2$-doubled condition than under current atmospheric $CO_2$ concentration as the plant type becomes more erect.

• Korean journal of applied entomology
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• v.50 no.4
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• pp.379-382
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• 2011

The damage rates of peach pyralid moth(Dichocrocis punctiferalis), which damages the chestnut fruits, were investigated annually from 1995 to 2010 according to year, region, and maturity. The damage rate by D. punctiferalis was the highest (34.5%) in 1998 and was the lowest (17.9%) in 2000. The pattern of the damage rate showed a repeating three-year cycle. There was a negative correlation ($-0.6261^*$) between rainfall and damage rate. There was a positive correlation ($0.5826^*$) between temperature and damage rate. The average damage rate of all surveyed regions was 22.2%. Of the surveyed areas, Hapcheon had the highest at 27% and Hamyang had the lowest at 15.0%. The damage rate of chestnut fruit depending on the maturity was 26.1% in an early maturing cultivar (Dantaek), and 19.3% and 21.1% in a late maturing cultivar (Eungi) and a medium maturing cultivar (Chukpa), respectively.