• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.3
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• pp.206-214
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• 1994

This experiment was conducted to find out the response of orchardgrass (Dactylis glomrrata L.) varieties to grazing at the condition of monocultures and mixed pastures on the field of Livestock Experiment Station at Suwon from Sep. 1989 to Oct. 1991. The varieties of orchardgrass used in this experiment were Potomac, Hallmark and Syn. No. 2 as a early maturing type, and Lidacta, Rancho and Syn. No. 10 as a late maturing type. The results obtained were as follows: I. Heading date of early maturing varieties among orchardgrass like as Potomac, Hallmark and Syn. 2 ranged from May 9 to May 14. Otherwise those of late varieties(Lidacta Rancho and Syn. 10) were between May 21 to May 25. Leaf types of early varieties were shown erect, those of late varieties were erect or semi-erect. 2. In dry matter production per ha, mixture with Rancho variety(T5) was the highest as 7.818 kg and mixture with Hallmark(T2) was the lowest as 7,013 kg. But there was not significantly different(P>0.05) among mixtures. While in monocultures, Syn. 10 variety was the highest(6.626 kglha) and Lidacta was Iowest(5,775 kg). But no difference was found(P>0.05). 3. In mean grass height after grazing, mixtures with early maturing types were higher as 9.8 cm than that of late (8.8cm), and early types were higher as 10.5cm than that of late(9.4cm) in monocultures. But there was no significant difference both mixtures and monocultures.

• 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 Korean Society of Grassland and Forage Science
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• v.32 no.3
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• pp.229-236
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• 2012

This experiment was conducted to evaluate agronomic characteristics and forage productivity of italian ryegrass cultivars at Seongju in the Kyeongbuk from 2010 to 2012. The experiment was arranged in randomized complete block design with three replications. Italian ryegrass cultivars were seeded on Oct. 12 in 2010 and Oct. 3 in 2011. The early-medium maturing cultivars were harvested on 29 Apr. and the medium late ones were harvested on 4 May in 2011. In 2012, the early-medium cultivars were harvested on 28 Apr. and medium late ones were harvested on 12 May. DM (dry matter) yield of the early-medium maturing cultivars 'Yeonbong3', 'Seongnong', 'Winter Hawk', 'Pride' and 'Kowinnearly' was 9,850, 9,778, 9,486, 9,363 and 9,267 kg/ha and DM yield of those were significantly higher (p<0.05) than other seven cultivars or ones. DM yield of the medium-late maturing cultivars 'Tetragold', 'Hwasan 101', 'Jumbo', 'Sungrazer', 'Master', 'SelectIV' and 'KB Royal' was 9,542, 9,492, 9,103, 8,981, 8,903, 8,870 and 8,681 kg/ha and DM yield of those were higher (p<0.05) than other three. Cold tolerance for 'Hwasan 101' was higher than others, in medium-late maturing cultivars. According to the results obtained from this study, it is suggested that early-medium maturing cultivars would be recommendable for DM production.

• Korean Journal of Plant Resources
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• v.27 no.5
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• pp.556-566
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• 2014

In this study, we collected 29 Kenaf (Hibiscus cannabinus L.) genetic resources from 10 countries to confirm the possibility of the introduction into Korea. The Kenaf (Hibiscus cannabinus L.) has the broad industrial use like feed and the 5 times more strong $CO_2$ absorption capacity compared to general plant. So recently it is considered as a good industrial source. We analyzed ecotype, growth and development, yield and feed value of collected resources. They were divided into 3 groups depending on flowering time, early maturing type blooming in early July, mid-late maturing type blooming from end of August to early September and late maturing type blooming in end of October. Early maturing type could get fruitful seed but dropped yield (average 7,895 kg/10a) and late maturing type could get high yield (average 12,572 kg/10a) but deletion. The other side mid-late maturing type could get yield over a certain level (average 11,207 kg/10a) and fruitful seed was ensured. The yields analyzed by resources indicated that K12 (Hongma 300) collected in China, K25 from India, K22 from Russia and K21 (Khonkaen 60) variety from China were more than 13,500 kg per 10a. Feed value of early maturing type had inclined to more better than other types, but like dry digestible matter (DDM) and dry matter intake (DMI) of some late maturing types like K12, K21, K22 which had a high yielding ability were more better than that of early maturing types'. So relative feed value (RFV) which considered comprehensive item for feed value were indicated K21 was 102.5, K12 was 116.2 and K22 was 120.2. 'Jangdae' the variety developed in Korea which could complement of other types' had a good quality for yield 10,975 kg/10a and 12.5% crude protein content and 101.9 of the relative feed value. So we need to be taken power to collection of mid-late maturing types resources.

• 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 Animal Science and Technology
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• v.46 no.2
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• pp.227-234
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• 2004

This experiment was conducted at Cheonan Yonam Experimental Livestock Farm in 2001-2002 to detennine the effect of harvest date(20 April, 26 April and 4 May) on forage yield and quality of rye varieties of three different maturing groups(early maturing variety = ‘Koolgrazer’ midseason maturing variety = ‘Horni122’ and late maturing variety = ‘Danko’). The heading date of Kooigrazer, Hornil22 and Danko were 17, 22 and 29 April, respectively. Dry matter percentage increased from 15.6 to 21.6% as the harvest date was delayed from April 20 to May 4. Among the rye varieties tested, dry matter percentage of Koolgrazer, Hornil22 and Danko were 20.9, 18.8 and 16.3%, respectively. Dry matter yield increased from 1l.2 to 13.9 ton/ha as the harvest date was delayed, but no significant difference among rye varieties. As the harvest date was delayed, total digestible nutrients(TDN) yield also increased significantly from 7.4 to 8.4 ton/ha However no significant difference was found among rye varieties. Crude protein(CP) percentage decreased from 20.3 to 17.1% as the harvest date was delayed, and CP percentage of late maturing variety, Danko, was significantly higher than that of the other varieties. In content of fiber component(NDF, ADF, ADL, hemicellulose and cellulose) of rye, the late harvest date(4 May) showed the highest among harvest dates. From comparisoo within rye varieties tested, Kooigrazer, a early maturing variety had higher than a rnidseason and late maturing varieties, Hornill22 and Danko. The cellulase digestible of organic matter of dry matter(CDOMD) decreased as the harvest date was delayed. Among the rye varieties tested, the CDOMD of a early maturing variety, Koolgrazer was the lowest. Our study differences of winter rye in forage yield and quality resulting from variety maturity and harvest stage. A early maturing variety, Kooigrazer should be harvested between 24 and 28 April, Hamill 22(midseason maturing variety) harvested between 29 April and 3 May, Danko(late maturing variety) harvested between 4 and 8 May for maximum forage yield and optimum quality.

• Korean Journal of Animal Reproduction
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• v.13 no.3
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• pp.127-133
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• 1989

This study was undertaken to understand development stage of ovary and changes of hormones concentration from February to May in the Israeli carp, Cyprinus carpio. The results obtained in these experiments are as follows ; 1. Serum LH levels began to increase sharphy in March, coinciding with the onset of rapid ovarian development. 2. LH levels were well correlated with changes in gonadosomatic index. 3. Dramatic increase in gonadosomatic index occurred during the months of March. 4. Ripe stage(Stage Ⅴ) rapidly increase in March. 5. Early perinucleolus oocyte radpily develop into late perinucleolus oocytes in March. 6. The vitellogenic phase begins as these late perinucleolus oocytes become transformed into early maturing oocytes through the accumulation of yolk. 7. The cytoplasm completely fills with yolk as oocytes reach the late maturing stage. 8. Changes in the microscopic appearances of the ovaries were well correlated with changes in both gonadosomatic index and macroscopic appearance. 9. It is concluded from these observations that LH plays a major role in sexual maturation of the Israeli carp.

• Korean Journal of Agricultural Science
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• v.45 no.3
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• pp.355-363
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• 2018

This study was conducted to investigate suitable rice cultivars for various rice based cropping systems in a paddy field in the Yeongnam plain area. Thirteen rice cultivars (5 early, 3 medium and 5 mid-late maturing cultivars) and three transplanting dates (June 5, June 25 and July 5) were evaluated in this study. The mid-late and early maturing cultivars for the July 5 and June 25 transplanting headed before August 30 which is the safe heading date in the Yeongnam plain area, ranging from Aug. 26 - 28 and Aug. 18 - 23, respectively. The safe harvest time of rice for double and triple cropping systems should be before the middle of October for the cultivation of the succeeding winter crops. The rice yield was the highest for the June 5 transplanting regardless of the rice cultivars, and it gradually decreased as the transplanting date was delayed from June 5 to July 5 due to a decrease in the spikelet numbers per panicle number and in the ripened grain rate. In contrast, the other yield parameters that include the panicle number per $m^2$, the 1,000-brown rice weight, and the ripened grain ratio were not significantly affected. The result indicates that based on the milled rice, heading time and harvest time, a medium maturing cultivar (Haiami and Samdeog) would be applicable to a winter barley/wheat, garlic/onion-summer rice double cropping, while a mid-late cultivar (Saeilmi, Saenuri and Hyunpoom) would be suitable for a spring potato/waxy corn-summer rice double cropping in the Yeongnam plain area. On the other hand, an early maturing cultivar (Unkwang, Jokwang and Haedamssal) would be preferable for a triple cropping because of the short growth period of rice.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.3
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• pp.215-222
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• 1994

This experiment was conducted to find out the response of orchardgrass (Dactylis glorneruta L.) varieties to grazing at the condition of monocultures and mixed pastures on the field of Livestock Experiment Station at Suwon from Sep. 1989 to Oct. 1991. The varieties of orchardgrass used in this experiment were Potomac, Hallmark and Syn. No. 2 as a early maturing type, and Lidacta, Rancho and Syn. No. 10 as a late maturing type. The results obtained were as follows: 1. Herbage utilization of mixture with Hallmark variety(T2) was the highest as 78.2% and that with Rancho variety(T5) was the lowest as 70.2%. but there was no difference(P>0.05). Mixtures with early maturing varieties(T1, T2 and T3) were higher as 77.4% than those with late varieties(T4, T5 and T6) as 72.9% in herbage utilization. In monocultures Rancho variety(T5) was the highest as 68.6% and Lidacta variety(T4) was the lowest as 58.8%, and mixtures with early maturing varieties(T1, T2 and T3) as 66.6% were higher than those of late(T1, 72 and 73) as 64.6%. 2. The content of crude protein of 6 mixed pastures ranged from 19.7% to 22.8%, and those of ether extracts, crude fiber, crude ash and nitrogen free extract were 6.6 to 7.5%, 24.9 to 26.2'76, 1 1.5 to 1 1.9% and 33.6-35.4 8, respectively, But there were not different significantly(P>0.05). In monocultures, significant difference by variety was observed in crude protein content(P<0.05). 3. In botanical composition, there was just a little different among 6 mixtures, having 90% or more in grass percentage. The percentages of each orchardgrass varieties were decreased, but those of perennial ryegrasses were increased as grazing sesson was progressed in all treatment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.5
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• pp.335-340
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• 2002

To evaluate the efficiency of anther floating culture according to the maturing group, the varietal difference and classification of fifty varieties was conducted in N6 liquid medium containing 1mg $l^{-1}$ NAA, 0.25 mg $l^{-1}$ kinetin. The efficiency of callus induction was widely ranged from 0 to 113.4%, but the mean callus induction was not significantly different among maturing groups. The efficiency of anther floating culture showed the highest variation in early-maturing group among three maturing groups. The varieties with the best callus induction were Sambaegbyeo and Jinbuolbyeo, while the recalcitrant variety was Obongbyeo in early-maturing group. The efficiency of plant regeneration showed the highest trends in late-maturing group among three maturing groups. The fifty varieties were classified into three groups (distance=0.78) by cluster analysis based on the callus formation and plant regeneration. Group including only two varieties, Shinunbongbyeo and Sambaegbyeo had the excellent androgenic efficiency, and the medium efficiency of Group was included thirty-six varieties. Whereas twelve varieties, including three Tongil varieties were fell into the bad efficiency of Group. Especially, Tongil varieties containing Japonica rice, Obongbyeo were the recalcitrant genotypes for the anther floating culture.