• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.2
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• pp.150-156
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• 1995

Planting date is the most important factor in determining winter survival of Crop plants. The objective of this study was to explore the effect of planting date on the development of freezing tolerance and winter survival of canola. Six winter cultivars were planted at three different dates during the fall on the Michigan State University Research Farm at East Lansing, MI. Freezing tolerance was determined by ion leakage tests every 15 days after planting until middle of November. Winter survival was evaluated by counting the live plants in the fall and next spring. Planting date as well as cultivar treatment had a significant effect on freezing tolerance and winter survival A different pattern in development of freezing tolerance was observed for different planting dates. There was a high correlation between freezing tolerance and winter survival suggesting that freezing tolerance could be a useful predictor for winter survival.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.259-267
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• 2010

This study was performed at Rice and Winter Cereal Crops Department of NICS during 2007 and 2008 to investigate the characteristics of rice leaf emergence and to obtain basic data which can be used for rice growth simulation model by which we can forecast rice growth stage and heading date accurately under different cultivars, transplanting date, and climatic conditions. To confirm leaf emergence rate according to rice maturing ecotype, we surveyed the leaf emergence rate and heading date of Unkwangbyeo, Hwayoungbyeo and Nampyeongbyeo which are early maturing, medium maturing and medium-late maturing cultivars, respectively, according to seedling raising duration and transplanting time. When seedling duration was 15 days, the growth duration between transplanting time and completion of flag leaf emergence on main culm were 51.5~78.3 days in Unkwangbyeo, 55.3~87.9 days in Hwayoungbyeo and 58.4~98.4 days in Nampyeongbyeo, respectively. When seedling duration was 30 days, they were 50.1~75.5 days in Unkwangbyeo, 52.4~84.7 days in Hwayoungbyeo and 56.4~93.8 days in Nampyeongbyeo, respectively. As transplanting time delayed, the emerged leaf number after transplanting decreased in all rice cultivars. The cumulative temperature between transplanting time to completion of flag leaf elongation on main culm were $1,281^{\circ}C{\sim}1,650^{\circ}C$ in Unkwangbyeo, $1,344^{\circ}C{\sim}1,891^{\circ}C$ in Hwayoungbyeo and $1,454^{\circ}C{\sim}2,173^{\circ}C$ in Nampyeongbyeo, respectively. Leaf emergence rate on main culm were precisely represented by equation, y = $y_0$ + a / [1 + exp( - (x - $x_0$) / b)]^c, when we used daily mean temperature as variable.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.4
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• pp.238-244
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• 1995

The objective of this study is to obtain the basic data for investigating the effects of organic reserves on winter survial or regrowth yield. Forage rape(Brassica napus L.) was sown on Sep. 1, 1994. Experimental plots were divided into three replicates under 6 different cutting dates(l0 days interval from Oct. 15 to Dec. 4). Field-grown palnts were sampled on the each cutting date and on the wintering period (Jan. 16) to analyze the nitrogen and non-structural cahohydrate reserves. The rate of winter survival and regrowth yield were also measured in the spring of next year. On the before wintering, dry matter yields were 152, 274, 500, 718, 776 and 981 kg/lOa, respectively, from the cutting date on Oct. 15, Oct. 25, Nov. 4, Nov. 14, Nov. 24, and Dec. 4. Cmde protein yield significantly increased as cutting date was later until Nov. 14, thereafter a significant increase did not occured. Nitrogen and starch contents per plant significnatly increased as the cutting date was later. The increasing rate of starch was greatly higher than that of nitrogen. On the wintering period, nitrogen reserves in mts were 85.3, 68.8, 47.6, 28.3, 44.3, and 55.3 mglplant, and starch reserve were 11 1.3, 75.3, 39.3, 19.6, 26.4 and 34.6 mglplant, respectively, in the plots cut on Oct. 15, Oct. 25, Nov. 4, Nov. 14, Nov. 24, and Dec. 4. It showed that carbohydrate reserves were much highly utilized than nitrogen reserves during wintering period. The rates of winter survival were 91, 83, 46, 22, 35 and 43% and regrowth yields were 692, 545, 316, 84, 127 and 140 kgD.M/lOa, respectively, in each plots. The highly significant correlation (p<0.01) between the level of organic reserves and the rate of winter survival or regrowth yield were obtained.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.3
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• pp.158-164
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• 2019

We examined the adaptability of Korean winter forage crops such as Italian ryegrass, barley, oat, and triticale in Uzbekistan. The overall growth before wintering was slightly different between Uzbekistani and Korean varieties, but there was no significant difference among winter forage crops. The heading date of the Korean triticale 'Shinyoung' was the earliest, (April 4), and the heading date of the Uzbekistani triticale 'Frack cerebristy' was quite late, (April 25). The heading date of the Korean Italian ryegrass 'Kowinearly' was four days earlier than that of 'Kowinmaster,' on April 13, and that of the Korean barley 'Youngyang' and 'Yuyeon' were five days earlier than that of the Uzbekistani barley 'Bolgaly'. The maximum dry matter yield of winter forage crop was from Uzbekistan triticale, 'Frack cerebristy', which was 13,536 kg/ha. The dry matter yield of Uzbekistan barley was 8,222 kg/ha. Compared with Uzbekistan barley, 'Bolgaly', yields of Korean barley 'Youngyang' and 'Yuyeon', Korean oat 'Samhan', and Korean Italian ryegrass 'Kowinearly' and 'Kowinmaster' were 59~64%, 125%, and 113~133%, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.1
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• pp.30-37
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• 1991

This experiment was conducted to determine optimal sowing date and method of Italian ryegrass(Lo1iuwr wzultiflorum. Tetrone) in paddy of Gyeong Nam area. Treatments given were four sowing dates(Sep. 30, Oct. 10, Oct. 20 and Oct. 30) and four sowing methods (broadcasting on tillage ridging, broadcasting on zerotillage ridging, boundless broadcasting and alternated drilling). The characteristics of growth, winter survival, yield(fresh and dry matter) and nutr~ent quality were observed. The results obtained are summarized as follows: 1. Winter survival and yield components such as plant height, and number of stem were the highest due to higher survival tillers at the sown time of Sep. 30(p<. 05). 2. Plants sown on Sep. 30 showed the highest fresh and dry matter yield. Yield was decreased as delaying the date of sowing. Fresh and dry matter yield sown on Oct. 10, were obtained 7600 and 1100 kg, respectively, aftenvardly sign~ficantly decreased(p< .05). 3. Effect of sowing time and method on chemical composition were not recognized. 4. Winter surviva: sown on boundless-broadcasting was lower(p<. 05) than those of sown on broadcasting on ridging and alternated-drilling. 5. Fresh and dry matter y~elds were the highest when sown on broadcasting on tillage ridging but that of sown on houndless-broadcasting was relatively low. 6. The growth and forage yield were enhanced by sowing up to Oct. 10 and by sown on broadcasting on ridging (tillage or zerotillage).

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.3
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• pp.156-161
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• 2023

This study was conducted to determine the appropriate seeding dates by verifying the difference in winter survival and productivity of alfalfa according to fall sowing dates in the central area of South Korea. The experiment was conducted for 2 years (2020 and 2021) at the field in the Department of Animal Resources Development, NIAS located in Cheonan. Sowing dates started from September 18 to November 8 with 10 days of intervals during 2020 and 2021; SO1 (September 18), SO2 (September 28), SO3 (October 8), SO4 (October 18), SO5 (October 28), and SO6 (November 8). After sowing, the winter survival rate was measured in the spring of the following year, and the dry matter yield was measured by harvesting at 10% flowering and harvesting five times a year. SO6 failed to winter survival, and SO5 also had a lower winter survival rate than SO1~4 (p<0.05). The average annual dry matter yield of alfalfa linearly decreased with delaying sowing dates (p<0.05). The feed value did not differ in the same year by delaying the sowing date in the same year. These results suggest that sowing date should be started before October 18 to increase winter survival and productivity of alfalfa in the central area of South Korea.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.3
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• pp.169-175
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• 2022

This study aimed to examine the changes in dry matter yield and growth characteristics of alfalfa (Medicago sativa L.) in response to variations in sowing dates during the autumn season of 2021-22 in a dry paddy field of Chilbo-myeon, Jeongeup-si, Jeollabuk-do. Treatments comprised four sowing dates at 10-day intervals, i.e., October 8, October 18, October 28, and November 8, 2021. The winter survival rate of alfalfa showed a significant difference between different treatments but was at a satisfactory level for all (p<0.05). The winter survival rate for the fourth sowing date, a month later than the first sowing date, was approximately 11.7% lower than that for the first sowing date. The plant height ranged between 82.3-93.1 cm and 60.5-63.7 cm at the first and second harvest, respectively, smaller at the second harvest than at the first harvest. The total dry matter yield of alfalfa was the highest at 13,316 kg/ha for the first sowing date, and the later the sowing date, the lower the dry matter yield. The protein content of alfalfa ranged between 13.6-17.3% in the first harvest, lower than the standard alfalfa protein content of 20% or more. In relative feed value, the first sowing (Oct. 8) was the most significantly higher in the first harvest (p<0.05). These results suggest that the early and mid-October sowing dates are optimum for sowing alfalfa during autumn and result in improved plant growth, dry matter yield, protein content, and winter survival compared to those at later sowing dates. Therefore, dry paddy fields can be safely employed for alfalfa cultivation with sowing dates in early and mid-October during autumn.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.1
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• pp.1-8
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• 1996

The objective of this study is to obtain the basic data for investigating the effects of organic reserves on winter survial or regrowth yield. Forage rape (Brussicu napus L.) was sown at 10 day> interval from Sep. I to Nov. 1. Field-grown palnts were sampled on the before wintering (Dec. 4) and on the wintering period (Jan. 16) to analyze the nitrogen and non-structural cahohydrate reserves. The rate of winter survival and regrowth yield were also measured in the spring of next year. On the before wintering, the dry matter yields from the plots sown on Sep. 1, Sep.11 and Sep. 21 were 860, 596 and 260 kg/lOa, respectively. No. harvest was canied out on the plots sown after Oct. 1 because the growth state was not enough to cut. Both of nitrogen and starch contents per plant significantly increased as the seeding date was later. On the wintering period, the contents of nitrogen reserves in roots were 176.8. 120.1, 71.7, 84.0, 72.1, 45.3 and 33.3 mg/plant, those of starch reserves were 199.0. 55.8, 21.8, 92.6, 86.5, 36.4 and 29.0 mglplant, resepctively, in the plots sown on Sep. 1, Sep. 11, Sep. 21, Oct. I, Oct. 11, Oct. 21 and Nov. 1. The rates of winter survival were 40, 36, 33, 85, 87, 59 and 49% and regrowth yields were 161, 86, 65, 520, 451, 121 and 33 kgD.M/lOa, respectively, in each plots. 'Ihese results clearly showed that seeding date has a close influence on the level of organic reserves and forage yield, and that the possibility of continuous utilization on the before and alter wintering is extremely limited by seeding date.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.1
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• pp.42-49
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• 1994

To examine the productivity, growth characteristics, and nutritive value of forage rye at the southern region of Korea, fourteen varieties of rye were sown at Nov. 13, 1992 at the plot of experiment farm of Crop Experiment Station, Mokpo Branch, and over winter survival rate, heading date, yield, yield components and nutritional values were measured. All the varieties used in this experiment showed 100% over winter survival rate at the sowing date of Nov. 13. Heading dates of all the varieties ranges from Apr. 25 to May 10, which seems to be early enough to get high yield. The varieties, Paldal-hod, and Danko introduced from Japan appear to be the most recommended ones in the southem region of Korea. They showed early heading date of Apr. 25, large plant height, greater number of leaves, high yield, low content of crude fiber and crude fat, high crude protein, NFE, and crude a5h.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.207-213
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• 2010

Changes of heading response and leaf production of winter cereals according to cultivar and sowing date in spring, were investigated in Suwon Korea during three years from 2007 to 2009 to obtain information on use as spring living mulch of winter cereals for weed suppression without herbicide in environment-friendly crop production. Rye showed variation among cultivar in heading response according to sowing date, which means that cultivar selection for living mulch is important in rye. Cultivar Prima and Wintergreen had not headed in sowing during March with low soil temperature in contrast to cultivar Koolgrazer and Gokwoo which had headed somewhat even until sowing in early May with relative high soil temperature. Barley and wheat showed distinct characteristics in heading response between sowing before and after early April compared to rye. Leaf production for soil covering was higher in barley than wheat, and cultivar Mirak than Ol within barley in 2007, respectively. Leaf production were not different much among rye cultivar in sowing during early or mid April, but it was different in sowing after mid April indicating that winter cereal cultivar with high leaf production could be selected in late sowing. It is thought that rye cultivar Duru was the most proper cultivar for spring living mulch in the point of high leaf production in addition to low heading in sowing after March.