• Journal of The Korean Society of Grassland and Forage Science
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• v.12 no.2
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• pp.111-122
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• 1992

This experiment was conducted to determine the effects of spring seeding dates on the growth, yield and quality of early and late maturing spring oat (Auena sativa L.) cultivars on the forage experimental field, College of Agriculture, Seoul National University, Suwon from March to June, 1991. The experiment was arranged as a split plot with three replications. Oat cultivars, Cayuse and Speed oat, were the main plots, and seeding dates consisted of March 15, 22, 29, April 5 and 12 were the subplots. 1. A 7-day delay in seeding represents approximately 3~8 days being early in heading. The heading date of the early maturing cultivar, Speed oat, was 14 days earlier than that of the late maturing cultivar, Cayuse. 2. The concentrations of Crude protein (CP), Acid detergent fiber (ADF), Neutral detergent fiber (NDF) and zn uitro dry matter digestibility (IVDMD) of the late maturing cultivar, Cayuse, harvested May 29 were 19.6, 30.0, 44.9, and 82.7 %, respectively, but those of the early maturing cultivar, Speed oat, were 14.8. 33.3. 52.3, and 71.2 %, respectively. Chemical analyses of oat forage indicated that the contents of crude protein and lVDMD were increased from March 15 to April 12 seeding, while crude fiber was decreased. 3. Theaverage dry matter, IVDDM and CP yields of oats harvested May 29 were 2,960, 2,435 and 572 kg per ha, respectively with the late maturing cultivar. Cayuse. while the early maturing cultivar, Speed oat, recorded 3,255, 2.298 and 475 kg per ha, respectively. No significant dry matter yield differences were found among the different seeding dates of March 15, 22 and 29 for the two oat cultivars. but a significant yield decrease was found from April 5 seeding. No interactions in dry matter yield were observed between oat cultivars and seeding dates. 4. Maximum Leaf area index (LAI) and Leaf area index duration (LAID) were observed with earlier seeding and the LA1 of Cayuse cultivar was twice or three times as much as that of Speed oat cult~var as the growth progresses. 5. As the seeding date was earlier. the Crop growth rate (CGR) of the late maturing cultivar, Cayuse. was increased continuously. but that of the early maturing cultivar, Speed oat, was declined after May 29. This trend was also found on the Net assimilation rate (NAR) of Speed oat cultivar. The present experiment indicates that spring oats can be successfully produced as forages by seeding in March with early maturing cultivars.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.156-163
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• 2020

The purpose of this study was to select the wheat varieties, among 8 domestic cultivates, that are suitable, for use as grain feed at paddy fields in the Honam region. The seeds of wheat were sown and harvested in Wanju County. Among the wheat varieties, "Jojoong" was the earliest for its heading date on April 15, and it showed the earliest day for the maturing date on May 24. The heading date of "Baegjong" was the same as that for "Keumkang" on April 18, and the maturing date was one day later than that for "Keumkang" on May 29. But there was no significant difference of heading and maturing dates among the 8 wheat varieties. The lowest number of spikes/㎡ was 513/㎡ of "Goso", and the highest number of spikes/㎡ was 974/㎡ of "Chongwoo". The spikes/㎡ and yield of "Baegjon" was 542kg/10a and it was the highest yielding variety among the 8 wheat varieties. The chemical compositions of DM (dry matter) and CP (crude protein) on rumen digestibility were not significantly different among the 8 wheat varieties. Furthermore, rumen digestibility of DM and CP, and the nutrients value were slightly higher than those of corn. The domestic 8 wheat varieties for grain feed, with their high nutrient qualities, could eventually replace imported grain feed and wheat grain feed. These 8 varieties are cost-effective feed and paddy field fodder for livestock farmers.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.3
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• pp.254-260
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• 1984

As a basic study for development of early wheats an experiment was carried out at four sites of Korea by use of 60 varieties. Analysis of variance for heading and maturing dates revealed that there were highly significant among varieties, but not significant among variety x location-interactions, thus indicating the stable response for earliness at all locations of each variety. Grain filling periods of each variety showed the stable response at all locations like those of heading and maturing dates, however, there showed significance among locations for early group, and among varieties for late group. High correlations were between growth habit and winter survival for early varieties, and between shortday length and grain filling period for late one. Interior factors most closely related to heading date were growth habit and winter survival, and winter survival showed highly negative correlation with heading date. It needs to breed the early wheats adaptable for southern and/or northern areas separatively. The earlier heading and maturing dates of wheats were, the shorter internodes of culm are, appearing the outstanding phenomenon in early wheats. Heading date appeared negative correlations with test weight and with number of culm before winter, but showed positive correlation with number of kernels/spike.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.4
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• pp.297-302
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• 2015

This experiment was conducted to evaluate the agronomic characteristics and forage production of Italian ryegrass cultivars at three locations (Gurae, Sungju and Cheonan) from 2013 to 2014. The experiment employed a randomized complete block design with three replications. The seven cultivars used in this experiment were 'Korwinearly', 'Florida80', 'YounbongI', 'YounbongII', 'YounbongIII', 'KeimyungI' and 'KeimyungII' varieties. Italian ryegrass varieties were seeded on October 4 at Gurae, October 8 at Seongju and October 3 at Cheonan in 2013. The Italian ryegrass varieties were harvested on April 26 at Gurae and Seongju, and on April 24 at Cheonan in 2014. Although the seven cultivars had resistance to foliar diseases and insects and high winter survival, they has little lodging resistance. The heading dates for 'Younbong I', 'Younbong II' and 'Keimyung I' were earlier than for other varieties at the three locations. Dry matter (DM) content and plant height in the early maturing cultivars were higher than in other cultivars at the three locations. The fresh and DM yields of the early maturing cultivars were also higher than others at the three locations. The results of this experiment indicate that the heading date for early maturing cultivars is earlier, and the plant height is higher than for other cultivars. Early maturing cultivars had higher DM content as well as fresh and DM yields of Italian ryegrass. Therefore, early maturing cultivars should be recommended as high-yield forage in double-cropping systems because of their superior production of forage and early heading date.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.51-55
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• 2005

The characters associated with the quality of rice and the factors involved in the production of high quality rice as the proper transplanting time was examined at Unbong the southern alpine area from 2002 to 2004. The rice cultivars tested were Samcheonbyeo (Early maturing one), Sangmibyeo (Sub-early maturing one). The number of spikelets were increased as earlier the transplanting date in all cultivar, The ripened grain rates were highest transplanted on May 21 for Samcheonbyeo, and May 1 for Sangmibyeo. The highest head rice yield was obtained when transplanted on May 21 and May 1 for Samcheonbyeo and Sangmibyeo, respectively. The optimum transplanting dates according to maturing types with respect to the yield of head rice, ripened grain rates and rice quality were May 21 for early maturing type and May 1 for sub-early maturing type.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.6
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• pp.541-549
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• 1992

Lodging and rainfalls during ripening periods and ripening patterns were studied by the different maturing varieties and different seeding dates in labour saving-direct seeding cultivation of rice. Period of emergency in earlier seeding plot was longer than later seeding plot and standing seedlings per unit area and rate of standing seedlings were more and high by the later seeding date. Number of panicles per unit area was decreased by the later seeding dates. On the other hand, the rate of effective tillers was lowest at later seeding plot. Days from seeding to flowering were shortened by the later seeding dates due to the increase of daily growth temperature and reduce of day length. There was much rainfalls during ripening period of early maturing varietal group, however not much rainfalls during ripening period of medium and late maturing varietal groups. The degree of lodging at field was severer by the amount of rainfalls during ripening period. Earlier seeding plots and earlier maturing varietal groups. of used varieties were revealed heavier lodging compared to later seeding plots and later maturing varietal groups. Yield and yield related characteristics were high and good by the earlier seeding dates, especially ripening rate was clear.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.125-130
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• 2008

This study analyzed the growth, seed quality, and yield of major early-maturing soybean cultivars by comparing them in order to utilize the research results in the selection of early-maturing soybean cultivars in multi-cropping farms in the Southern area. This field trial was conducted at Naju region (latitude $35^{\circ}04'N$, longitude $126^{\circ}54'E$), Jeonnam, with planting on June 15. The maturing date for Keunol-kong and Hwaseong-put-kong was found to be around September 12, which was earlier than other cultivars. Thus, there were advantages to introducing a cropping system as well as having good seed quality and high yield. On the other hand, the maturing date for Saeol-kong and Sinrok-kong was found to be around September 20, which was a little bit late; however, the seed quality of the cultivars was good and they had a high yield. Therefore, if we want to sow the following crops of soybeans around mid-September, Keunol-kong and Hwaseong-put-kong are advantageous, while for the seeding around late September, Saeol-kong and Sinrok-kong would be good. This study was also performed to identify the limitation time for early harvesting by reviewing seed quality and yield of major early-maturing soybean cultivars according to early harvesting. When harvesting Keunol-kong on September 6, which was six days earlier than the optimal harvesting time (September 12), there was no difference in seed weight, yield, or seed quality than those of the harvested at the optimum maturing time. As for Saeol-kong, when harvesting on September 18, which was six days earlier than the optimal harvesting time (September 24), there was no difference in seed weight, yield, or seed quality than those of the harvested at the optimum maturing time. Therefore, the stable limitation time for early harvesting of Keunol-kong and Saeol-kong was concluded to be six days earlier than the optimal harvesting time.

• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.407-413
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• 2023

This experiment was carried out to breed a medium maturing variety of Italian ryegrass (Lolium multiflorum Lam.) in Grassland and Forage Crops Division, National Institute of Animal Science, Rural Development Administration (RDA), Cheonan from 2019 to 2020. An Italian ryegrass variety, IR 604 is a tetraploid variety with green in leaf color and has half-erect growth habit in late autumn and erect growth habit in early spring, IR 604 was on May 17 in heading date as a medium maturing variety. Also, IR 604 was longer by 11 cm in flag leaf length and longer by 1.3 cm in plant height than those of the control variety, Kowinner, respectively. IR 604 was also thicker by 1.0 mm in stem thickness and strong in winter hardness. Dry matter (DM) yield (11,036 kg/ha) of IR 604 was 16.6% higher than that of Kowinner. Total digestible nutrient (TDN), crude protein (CP) and relative feed value (RFV) of IR 604 were 60.4, 13.8% and 100.6 which are 1.4, 3.3%, 7.7 higher than those of Kowinner, respectively. Acid detergent fiber (ADF) and neutral detergent fiber (NDF) of IR 604 were 35.5 and 56.7% which are 1.3 and 3.6% lower than those of Kowinner, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.313-326
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• 2023

Owing to adverse weather conditions, there is a heightened focus on actively researching the regulation of the sowing date in field crop cultivation. Soybean, a prominent field crop with extensive acreage and production, is a photophilic and thermophilic crop characterized by short-day photoperiodism. Identifying the optimal sowing time is crucial for mitigating the effects of severe weather conditions on soybean yield. Precise control over the timing of soybean sowing is the key to minimizing yield reduction due to unfavorable weather conditions. Temperature, photoperiod, and their interplay are the most significant factors influencing soybean cultivation among various weather factors. We conducted an experiment using three Korean soybean cultivars with varied maturities (Hwangkeumol: early maturing and Daewonkong and Pungsannamulkong: late maturing) in 2013 and 2014. Our investigation covered aspects of soybean growth, development, yield components, isoflavones, and visual seed quality. Across all three varieties, isoflavone levels increased with later sowing dates, while other measured components exhibited significant variations based on the sowing date. This study also provides valuable insights for the selection of suitable cultivars that perform well in soybean cultivation at various durations of maturity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.6
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• pp.434-438
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• 2001

Two late-maturing perilla cultivars for vegetables, ‘Ipdlkkae 1’ and ‘Manbaekdlkkae’, were planted on 15 May, 30 May, 15 June, 30 June, and 15 July in 2000 to determine the optimum planting date for seed production in Jeju Island. Significant interaction between cultivar and planting date was observed for number of days from planting to maturity. There were significant differences between two cultivars for days to flowering. Ipdlkkae 1 flowered two days earlier but matured one day later than Manbaekdlkkae. As planting was delayed from 15 May to 15 July, when averaged across two cultivars, days to flowering and maturity decreased from 137 to 77 days and 179 to 121 days, respectively. As planting was delayed, stem length, number of branches per plant and number of node on the main stem decreased from 150 to 81 cm, 17.0 to 7.3, and 16.9 to 10.3, respectively. Number of clusters per plant decreased 65.6 to 50.7 with delayed planting but number of capsules per cluster was not significantly affected by planting date. With delayed planting, 1,000-grain weight increased 3.2 to 3.9 g, but grain yield decreased from 1,820 to 1,338 kg/㏊. However, there was no significant difference for grain yield between 15 and 30 May plantings. The results of this study suggest that the optimum planting date for seed production of late maturing vegetable perilla may be from early May to late May in Jeju Island.