• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.77-77
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• 2017

The sensitivities to photoperiod and temperature give guidance to choose an adaptable genotype for specific area in soybean production. However, there is insufficient information about the variation of sensitivities to photoperiod and temperature with wide genetic background. We investigated the sensitivities to photoperiod and temperature using 82 soybean mini core collection lines provided by NIAS gene bank of Japan. The seeds were sown on 28 May and 4 August in 2015, 24 May and 5 August in 2016 at field in Saga, Japan ($33^{\circ}$ 14' 32'' N, $130^{\circ}$ 17' 28'' E) for the early (average photoperiod and temperature: 15.2 h and $25.1^{\circ}C$) and late (13.6 h and $27.2^{\circ}C$) sowing respectively. The plants were also grown in the growth chamber under 12 h photoperiod with three temperature regimes (day/night temperature: $25/18^{\circ}C$, $28/22^{\circ}C$ and $33/28^{\circ}C$). Emergence date, days to first flower were recorded with 10 plants in the field and 2 plants in the growth chamber for each line. The data for daily average temperatures and photoperiodic hours were collected from weather station. The days from emergence to first flower open (DEF) were varied from 23-92 (2015 and 2016) in early sowing whereas 18-68 (2015) and 18-59 (2016) in late sowing. The shortened DEF in late sowing could be caused by both short photoperiod and high temperature in late sowing. However, the accumulated temperatures during emergence to first flower open (ATEF) were less variable in comparison with DEF, suggesting the ATEF is dependent mostly on the photoperiod. The ATEF were found same between early and late sowing in some early flowering lines (e.g. $686.7^{\circ}C$ and $687.6^{\circ}C$ in HEUKDAELIPS, $728.8^{\circ}C$ and $706.3^{\circ}C$ in WILLIAMS'82) which indicated that these would be insensitive to day length. In the growth chamber experiment, the variation in both DEF and ATEF was a little greater at low temperature ($25/18^{\circ}C$) but almost same at middle ($28/22^{\circ}C$) and high ($33/28^{\circ}C$) temperatures. Since the less differences in ATEF were found between the three temperatures, it is suggested that the temperature plays only a quantitative effect on the flower initiation, and the large ATEF in some lines may indicate the stronger photosensitivity even at 12 h or longer juvenile phase. Some lines with the lowest ATEF regardless of growth conditions, such as FISKEBY V, KE 32 (ATEF: 559.6-666.5, 587.7-709.5) might lack the sensitivities to both photoperiod and temperature. The results suggested that soybean genotypes has wider variation in sensitivity to photoperiod, whereas less variation to temperature.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.2
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• pp.225-231
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• 2009

The objective of this experiment was to study the effects of grass maturity at harvest on the nutritive value of grass silage (GS) in relation to voluntary intake, digestibility, nitrogen (N) utilization and in sacco dry matter (DM) degradability. Silage was cut from a sward dominated by orchardgrass (Dactylis glomerata L.) at the late-vegetative (early-cut), internode elongation (mediumcut) and flowering (late-cut) stages of growth. The DM yield at harvest was the lowest for early-cut silage (5.4 t/ha) and increased to 6.5 and 7.0 t/ha for the medium and late-cut silage respectively. As the crop matured, the crude protein (CP) concentration decreased significantly (p<0.05) and there was a marked increase in acid detergent fiber (ADF) concentration (p<0.001). The three different silages were offered to four 18-month old Charolais wether sheep to measure the voluntary intake, in vivo digestibility and N retention over four 21-day periods in an incomplete changeover design. Silage degradability characteristics were determined using four fistulated sheep to measure DM degradability over 3, 6, 12, 24, 48 and 72 h. There was a linear decrease in the voluntary intake of silage fresh matter, DM, organic matter (OM) and neutral detergent fiber (NDF), digestibility of DM, OM, NDF, ADF and CP, and digestibility of OM in DM (Dvalue) ($P_L<0.01$) as harvesting of grass was delayed. Nitrogen intake, N output in urine, N output in faeces and N balance also linearly decreased ($P_L<0.01$) with postponed harvesting of grass for silage. DM degradability and effective degradability (ED) significantly decreased with increasing maturity of grass at harvest. The results suggest that harvesting date has a significant influence on the nutritive value of GS in terms of intake, digestibility, N balance and in sacco degradability in the rumen. It was concluded that early harvest GS ensured higher intake, digestibility, N intake and DM degradability in comparison with the medium and the late cut GS as a result of improved rumen N efficiency and utilization probably due to a better balance of available energy and protein.

• Korean Journal of Organic Agriculture
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• v.18 no.4
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• pp.573-586
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• 2010

This study was carried out to evaluate characteristics of Chrysanthemum sp. and to bioassay Tetranychus urticae, Nilaparvata lugens, and Aphis gossypii by different extracts part and method. Flower type of Chrysanthemum sp. line was anemone except 0706 line which was pompon. The flowering date was from April to June but 0721 line kept up November. They could overwinter except 0706 line. The Ethanol extracts of 0718 line of flower was high mortality as 63.8% on Tetranychus urticae. Ethanol mixed emulsifier extracts were the highest mortality as 69.4% at 5 days after. Mortality in water extract was lower than in ethanol and ethanol mixed emulsifier extracts. Ethanol mixed emulsifier extracts were higher mortality as 69.4% at 5 days after in 0718 line on Nilaparvata lugens. Mortality in water extract was lower than in ethanol and ethanol mixed emulsifier extracts. On Aphis gossypii, Chrysanthemum flower extracts could decrease the density of aphids in early days but the density of that was increase as time goes by because aphids produce offspring.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.4
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• pp.283-289
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• 2015

Three experiments were carried out to determine the effect of harvest maturity and management practices on the dry matter losses and morphological changes of round baled rye silage. Rye was harvested at three growing stages (boot, heading and flowering stage) in three different conditions i) with wilting (unwilted, short wilting and long wilting), ii) with inoculant treatment (untreated, inoculant A and inoculant B) and iii) with three different wrap colors (white, black and green). The morphological changes in round bale silage after 2 months was heavy in the early harvest and unwilted silage. However, harvesting after the heading stage did not change the shape, significantly. Inoculant treatment reduced the morphological changes and dry matter (DM) losses of round baled rye silage. DM loss was decreased with a delayed harvesting date and was significantly reduced by the inoculant. Dramatic changes in the shape were observed in all treatment at boot stage. Inoculant treatment resulted in more severe changes in the boot stage compared to untreated silage. Black color wrapping had the greatest impact among the wrap colors and there were no significant difference in the wrap colors. Harvest maturity and wilting periods was highly correlated (p<0.01) with morphological change. Result of these studies indicated that dry matter content is the most important factor that affects the morphological change in round bale silage.

• Horticultural Science & Technology
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• v.18 no.3
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• pp.378-382
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• 2000

For the production of second crop in 'Campbell Early' grape, the primary shoots were pruned at 3rd, 6th or 9th nodes from the shoot bases on 13 days, 23 days and 33 days after full bloom date on 7th June. Secondary shoots were sprouted 7~8 days after the pruning, and it took 19~25 days for the flowering on the secondary shoots. The flower cluster number on secondary shoots were 2.8 for 13 days after full bloom, and 3.2 for 23 days and 33 days after full bloom, meaning little effect by pruning time. The 3rd node pruning produced 2~2.4 flower clusters with flower cluster length of 9.3~10.4 cm, while the 6th or 9th node pruning produced 3.1~3.8 flower clusters with flower cluster length of 12~14.9 cm, showing superior flower cluster length for the 6th or 9th node pruning. The secondary shoots developed from the buds pruned 13 days after full bloom with pruning bud positions of 6th nodes demonstrated superior fruits with higher soluble solids and lower acidity than the rest of the pruning times and positions.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.1
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• pp.1-8
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• 2008

The concept of growing degree-days (GDD) is widely accepted as a tool to relate plant growth, development, and maturity to temperature. Information on GDD can be used to predict the yield and quality of several crops, flowering date of fruit trees, and insect activity related to agriculture and forestry. When GDD is expressed on a spatial basis, it helps identify the limits of geographical areas suitable for production of various crops and to evaluate areas agriculturally suitable for new or nonnative plants. The national digital climate maps (NDCM, the fine resolution, gridded climate data for climatological normal years) are not provided on a daily basis but on a monthly basis, prohibiting GDD calculation. We applied a widely used GDD estimation method based on monthly data to a part of the NDCM (for Hapcheon County) to produce the spatial GDD data for each month with three different base temperatures (0, 5, and $10^{\circ}C$). Synthetically generated daily temperatures from the NCDM were used to calculate GDD over the same area and the deviations were calculated for each month. The monthly-data based GDD was close to the reference GDD using daily data only for the case of base temperature $0^{\circ}C$. There was a consistent overestimation in GDD with other base temperatures. Hence, we estimated spatial GDD with base temperature $0^{\circ}C$ over the entire nation for the current (1971-2000, observed) and three future (2011-2040, 2041-2070, and 2071-2100, predicted) climatological normal years. Our estimation indicates that the annual GDD in Korea may increase by 38% in 2071-2100 compared with that in 1971-2000.

• Horticultural Science & Technology
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• v.17 no.2
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• pp.111-114
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• 1999

Experiments were conducted to select the optimum cultivars which are adaptable to South Korea through estimating the differences in daughter plant production and growth response among seven strawberry cultivars. In the vegetative stage, Nyoho, Akihime and Suhong produced more daughter plants than other cultivars whereas Akaneko and Tochinomine, which developed less runners, showed better condition in runner vigorness. The quality of daughter plants derived from forcing cultivars was uniform in general. Even though there was no significant differences in rooting among cultivars, runners from Akaneko and Tochinomine developed more roots and fresh weight of roots than other cultivars. In the forcing cultivars, Akihime showed the most excellent plant vigorness, yield and highest sugar content of fruits and also was 5 days faster than Nyoho in flowering date. However, the fruit tended to be softened. In the semi-forcing cultivars, Tochinomine was excellent in vigorness, firmness, sugar content of fruits and the average of fruit weight but low in flower numbers per cluster and late in the emergency of second flower cluster. Although Akaneko showed highest in sugar/acid ratio and rich in flavour, lighting treatment was recommended to this cultivar for early harvest because of softness of fruits.

• Korean Journal of Agricultural Science
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• v.1 no.1
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• pp.27-33
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• 1974

This experiment was carried out to determine the adequate amount of nitrogen for densely and lately seeded soybean, and the results obtained are as follows; 1) Various fertilization amounts of nitrogen did not effect the date of emergency, but the flowering and the maturing dates were delayed at the plots fertilized the nitrogen heavily. 2) In accordance with an increasing amount of nitrogen fertilization, the length of the stem and the internode was s gnificantly enlongated but the stem diameter was thinned down, and the latter was suggested to be the cause of lodging. 3) The 1,000 grain weight and the number of pods per hill were decreased according to the increasing the amount of nitrogen fertilization. 4) A highly significant difference in grain yield was recognized between varieties but among treatments. However, in case ot the extremly late cultivation, the grain yield of the early maturing variety (Choongbukbaek) was increased at the plot of 6 kg nitrogen.

• Korean Journal of Plant Resources
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• v.22 no.1
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• pp.1-4
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• 2009

This study was carried out to evaluate ecological growth characteristics of forty castor bean collections for biodiesel utilization. The emergence date and it's rate of collections was 15-16 days and 82.5%, respectively. It took 63-68 days from emergence to flowering. Stem length was ranged from 173 to 251 cm with an average 211.8 cm. The average stem diameter was 24.2 cm, and showed the high occurrence as 52.5% at the 20.4-24.9 cm. The node number was widely distributed as 13-22 and the average node number was 18.9. The seed numbers were widely distributed as 7-33ea, and the average liter weight of seed was 502.9 g of which minimum weight was 432.3 g and maximum weight was 572.5 g, and the gap between maximum and minimum was 140.2 g. It showed high difference. The 100 grain weight was distributed as 20.3 g-38.3 g which showed high differences between small grain and large grain collections. The seed numbers per plant were varied as 72 at the minimum and 1,011 at the maximum number, and average seed number was 465.2. The total yields of seed per plant were varied as 20 g-266.2 g, and the average yields were 128.1 g.

• Korean Journal of Plant Resources
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• v.16 no.3
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• pp.251-256
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• 2003

Genetic variation in field grown Korean ginseng(Panax ginseng C.A.Meyer) was evaluated using random amplified polymorphic(RAPD) markers. (This experiment was carried to collect the local native from farm of Chungnam National University in Korea in order to investigate genetic variation.) Some morphological characters showed considerable variation ranging 22 to 68cm in plant hight, 10 to 38mm in root diameter, 16 to 86g in root weight, and culum color and flowering date, respectively. Ten RAPD primers out of the 32 which produced reproducible bands in 662 Korean ginseng plants were selected for the further study. The total number of bands generated by 10 primers were 108 and among them 103 were polymorphic among the 662 plants with the polymorphism ratio of 94.5％. A total of 662 plants were classified into 16 groups based on polymorphic data with an URP 05 primer.