• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.222-226
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• 2004

This study was conducted to measure the major agronomic characteristics of 85 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. Average 1,000-seed weight (TSW) was 2.7 g. TSW of the collection from Hamyang was the greatest a 3.9 g, while the TSW of Pyungchang collection was the smallest as 1.7 g, 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. Seed coat colors of perilla accessions were dark brown (30％), brown (55％) and gray brown (6％), respectively, Among seed coat colors, brown color consisted of 91％. Stem height, the number of nodes, branches, flower clusters, and capsules per flower cluster, and the length of flower cluster were positively correlated occ, while these characteristics were negatively correlated with the number of capsules per flower cluster and 1,000-seed weight. These results allowed us to select 5 perilla collections, containing 1 collection with gray white seed color, and 4 collections over 2.5g 1000 seed weight, as parental lines in the breeding program.

• Journal of agriculture & life science
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• v.50 no.4
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• pp.113-125
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• 2016

This study was conducted to investigate the effect of low feeding level of concentrate after sexual maturity(14 month old) on the growing and breeding performances in Hanwoo cows. Eighteen cows(average body wt. 251kg) were alloted to two groups by completely randomized design, and fed a commercial formula feed by 0.8%(T1) and 1.2%(T2) of body weight for 30 months of total experimental period(feeding trial of 20 months, breeding trial of 10 months). When the results of this experiment compared to the Korean feeding standard for Hanwoo(2012), the reason of low growing performance in T1 was induced from low protein intake rather than energy. The change of body size by feeding levels was significantly appeared at chest width and body length, particularly chest width of cows in T1 was rather reduced by 3.7% in the final than the initial measurement. Ovarian size of T1 was only 63% of T2, and pregnancy rate(33.3% : 77.8%) and birth wight of calf(22.5kg : 29.5kg) were also seriously repressed by low intake of dietary protein after sexual maturity in Hanwoo cow. It was appeared that the growing and breeding performances of Hanwoo cows were more affected by the level of dietary protein rather than energy in the feeding after sexual maturity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.4
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• pp.359-365
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• 1994

A oat (Avena sativa) cultivar, 'Guiri 16', was seeded on Oct. 9, Oct. 24, Nov. 9, Nov. 24, Dec. 9 of 1991 and 1992 to determine usefulness of growing degree days (GDD) for predicting growth duration and the optimum seeding date of oats for grains in Cheju province. The later the seeding, the greater the number of days to emergence but the fewer the number of days to heading and maturity. As seeding was delayed, accumulated GDD from seeding to emergence generally tended to decrease but was less subjective to a constant downward tend over seeding date than the number of days. Accumulated GDD from emergence ot heading decreased with delaying seeding and accumulated GDD from heading to maturity decreased as seeding was delayed up to Nov. 24. As seeding was delayed from Oct. 9 to Dec. 9, to Dec. 9, leaf area index at heading decreased from 7.7 to 5.1 and dry matter yield at maturity from 1920 to 823 kg /10a in 1992-1993, and culm length 120 to 89cm on an average of 1991-1992 and 1992-1993. While the number of grains per panicle and test weight were not affected by seeding date in 1991-1992 and 1992-1993, the number of panicles per m$^2$ and grain yield were decreased when oats were seeded earlier or later than Nov. 9. 1000 grain weight was not affected by seeding date in 1991-1992 but greatest at Nov. 9 seeding in 1992-1993. The results indicate that optimum seeding date of oats in Cheju province would be early November. November.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.294-299
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• 1991

Eight naked barley cultivars were grown in three production systems to select proper cultivars for dual production of forage and grain and to determine production system x cultivar interactions. In the forage systems. barley was seeded on September 27 and October 17, harvested for forage on November 1. December 10 and February 12 from the September 27 planting (forage system I) and on December 10 and February 12 from the October 17 seeding(forage system II). In the grain-only system, barley was planted on November 5. In forage system I, oven-dried forage yields of eight cultivars ranged 195 to 296kg/10a and Saessalbori and Naehanssalbori yielded significantly higher than the other cultivars recording 280 and 296kg/ l0a, respectively. In forage system II, oven-dried forage yields of eight cultivars ranged 106 to 143kg/10a showing no significant difference among cultivars. Production system x cultivar interactions were significant for lodging at maturity, powdery mildew rating, 1000 kernel weight and grain yield. Leaf area index and biomass at heading, no. of spikes per $m^2$, no. of kernels per spike and test weight were not affected by the production system. Forage utilization delayed heading by 3 days and reduced culm length, spike length, lodging due to heavy rain on May 5 and lodging at maturity except for Songhagbori and Naehanssalbori. Forage utilization did not significantly affect grain yield from the September 27 planting but reduced 9% from the October 17 planting. while Saessalbori and Hyangcheonggwa 1 yielded significantly less than in the grain-only system. Songhagbori appears to be a proper cultivar for dual production of forage and grain in Cheju, considering forage and grain yields. and lodging and powdery mildew resistance.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.4
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• pp.349-356
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• 2006

Gonad development in the sandfish Arctoscopus japonicus was investigated using a histological method. Specimens were collected monthly from April 2003 to March 2004, in the East Sea of Korea. The gonadosomatic index (GSI) of females began to increase in August, reached a maximum in November, and declined sharply in December. By contrast, in males, the GSI began to increase in June and reached a maximum in August. The annual reproductive cycle of A. japonicus can be divided into four successive stages in females: the early growing (January-March), late growing (April-August), ripe and spent (September-November), and recovery (December) stages. Males passed through early growing (January-April), late growing (May-July), ripe and spent (August-November), and recovery (November-December) stages. These results indicate that the spawning season was from October to December. The egg diameter of mature oocytes was 3.12$\pm$0.02 mm. The relationship between fecundity (F$_e$) and body length (BL) was F$_e$=0.4693BL$^{2.6825}$. Fecundity ranged from 483-2,254 eggs in a body length of 14.3-22.9 cm and increased with body length. The body length at 50% maturity was 14.80 cm, which corresponded to an age of 2.40 years.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.210-221
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• 2000

The population habitat and density of Korean scallops, Chlamys farreri, were investigated to estimate population ecological characteristics from samples randomly collected around Wando from November, 1998 to October, 1999. Age and growth of the Korean scallops were determined from their ring radii. Maturation and spawning were studied using data of ovary maturity stage, gonadosomatic index, and fecundity. Seawater temperature and specific gravity ranged from 7.6 to $25.9^{\circ}C$ and from 1.0188 to 1.0260, respectively. Also dissolved oxygen and pH ranged from 6.48 to 9.50 ppm and from 8.17 to 8.80. Rocky and gravel bottom had a maximum habitat density of $$28.83 inds/100m^2$$ , which accounted for 82.4 % of the overall habitat area. The relationship between shell length (SL, mm) and shell height (SH, mm) of the Korean scallops was fitted : SH=1.021 SL+2.211 $(R^2=0.989)$. The shell length-total weight (TW, g) relationship was $TW=0.0003; SL^{2.837};(R^2=0.980)$. Then von Bertalanffy growth parameters were estimated from a nonlinear regression method, and the values were as follows : $SH_{\infty}=117.4 mm$K=0.61/year,; and; t_0=-0.017 year., The 50 % maturity at age was 0.21 year with the shell height of 18.3 mm, and spawning occurred twice a year, that is, June/July and October. The relationship between fecundity (Fc) and shell length was$Fc=697.03 SL^{2.683}(R^2=0.984)$, and the fecundity-gonad weight (GW, g) relationship was Fc=10,076,090 GW+15,608,781 $(R^2=0.990)$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.2
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• pp.158-164
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• 1985

The objective of the study was to investigate growth pattern of capsule and grain to improve grain filling during the grain filling period in sesame. Growth patterns of capsule and grain from anthesis to maturity were measured and compared by different plant types. Growth of capsule length started to grow just after anthesis and recorded maximum point at 35 days after flowering. and then decreased gradually. Growth of higher part capsule was worse than lower and middle capsules. Capsule growth of 2 carpels 4 loculi type showed better than 4 carpels 8 loculi type and BTB (branch, 3 capsules, 2 carpels, 4 loculi) type showed good growth due to its small reduction of higher part capsule length compared to those of lower and middle parts. The order of growth of capsule length were considered to be center capsule in main stem> center capsule in branch> side capsule in main stem> side capsule in branch. Growth of capsule width also showed maximum at 35 days after anthesis and then reduced. The order of growth of capsule width were lower part> middle part> higher part. Higher part capsule width of 3 capsules 4 carpels 8 loculi type showed serious decrease at late reproductive growth stage same as those of capsule length. Fresh one thousand grain weight showed peak at 35 days after anthesis and then reduced. The order of grain growth were appeared as lower part> middle part> higher part. Growth of fresh one thousand grain weight of branch and side capsule were lower than those of main stem center capsule, and 4 carpels 8 loculi type was deeply decreased at late flowering time in higher part such as the growth of capsule length and width. BTB (branch, 3,2/4) type didn't show much decrease in higher part fresh grain weight compared to those of other plant types in spite of its profitable character of lots of sink capacity. BTB type appeared to be ideal for improving grain filling and yield productivity in growing sesame in Korea.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.134-134
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• 2022

Mungbean is used for not only seed but sprout, so, consumption of mungbean has been on the rise in Korea. Life cycle of mungbean tends to be short among Legume. For that reason, Mungbean can be harvested for various cropping system and season per regions and farmers regardless of sowing date and harvesting date. So, Prior research is needed about growth characters and life cycle of mungbean per sowing period. Mungebean cultivar 'Dahyun' and 'Sanpo' supplied by Korea Agriculture Technology Promotion Agency(KOAT) is cultivated in wagner pot. Sowing period is proper time of seeding in Jeollanam-do and Gyeongsangnam-do that is major cultivation region of mungbean in korea from early May to mid July every 2 weeks. Length at maturity stage tends to increase from early May(sowing date: 4^th May) to early July(sowing date: 5^th July), but after that, It tends to decrease from mid July(sowing date: 19^th July). Number of branches and nods shows a similar trend. Length of pod has no tendency and no difference per sowing date. Number of pod per plants has also no tendency per sowing date. Test plots sowing in late May has the most number of pods.(Sanpo 22.9pods, Dahyun 16.8) Number of seeds per pod tends to increase to late May and Test plots sowing in mid July has the most number of seed per pod. In case of sowing at early May, Days of emergence is 7d. its summation of temperature is 132.2℃. After that, it tends to decrease to mid June. After mid June, Days of emergence is fixed to 3d. Average temperature growing up in this season, Summation of temperature from sowing to emergence takes the lowest point in test plots sowing in mid June.(Sanpo 88.6℃, Dahyun 88.6) Days of flowering tends to fasten from early May to mid July. Two cultivar shows same level. Days of maturity tends to fasten to mid June, after that tends to slow. In case that many research results about growth characters and life cycle mungbean per sowing period are drawn, it is expected that it result in increase of cultivation area and income of farmer.

• The Korean Journal of Malacology
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• v.26 no.4
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• pp.261-265
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• 2010

Reproductive biology of the purplish Washington clam, Saxidomus purpuratus was investigated based on the samples captured in Jinhae Bay, the East China Sea from January to December 2002. The gonad index (GI) began to increase in January, reached the maximum value in March. The reproductive cycle of this species can be divided into five successive stages: the early active stage (from November to January), the late active stage (from December to February), the ripe stage (from February to May and October), the spawned stage (from May to December), and inactive stage (from November to December). The spawning period was from April to December, and the main spawning occurred between June and August. The shell length at 50% group maturity was estimated to be 71.85 mm. The Sex ratio of this species was not significantly different a 1:1 sex ratio (P > 0.05).

• The Korean Journal of Malacology
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• v.17 no.1
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• pp.45-55
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• 2001

Gametogenes, reproductive cycle, first sexual maturity(biological minimum size), sex ratio and larval development of the marsh clam Corbicula japonica were investigated monthly by histological observations. Samples were collected in brackish water of Gokgang stream, Kyungsangbuk-Do, Korea, from August 1997 to July 1998. Sexuality of Corbicula japonica is dioecious and the species are an oviparous clam. The gonads are irregularly arranged from the sub-region of mid-intestinal gland in visceral cavity to reticular connective tissue of foot. The ovary is composed of a number of ovarian sac which are branched arborescent. Oogonia actively proliferate along the germinal epithelium of ovarian sac, in which young oocytes are growing. The testis is composed of a number of testicular tubules, and the epithelium of the tubule has function of germinal epithelium, along which spermatogonia actively proliferate. A great number of undifferentiated mesenchymal tissue and eosinophilic granular cells are abundantly distributed between developing oocytes and spermatocytes in the early developmental stages. With the further development of the ovary and testis these tissue and cells gradually disappear. Then the undifferentiated mesenchymal tissue and eosinophilic granular cells are considered to be related to the growing of the oocytes and spermatocytes. The spawning period is from July to September, and the main spawning occur between July and August when seawater temperatures reach above 22$^{\circ}C$. The reproductive cycle of this species can be divided into five successive stages; early active (February to April), late active (May to July), ripe (June to September), partially spawned (July to September), degenerative (September to October) and resting stage (October to February). Percentages of first sexual maturity of female and male clams ranging in length from 10 mm to 12 mm are over 50% and 100% for clams over 16.0 mm in shell length. Fertilized eggs or Corbicula japonica were 80-90 ${\mu}{\textrm}{m}$ in diameter. In the early embryonic development of C. japonica, the appearance of polar body, trochophore and D-shaped veliger were observed around 40 min., 27 hours and 4 days after spawning, respectively, at a water temperature of 26.5-28.$0^{\circ}C$. The size of larvae of early umbo stage was about 185-210 ${\mu}{\textrm}{m}$ in shell length, 160-180 ${\mu}{\textrm}{m}$ in shell height around 7 days after fertilization. The correlation of relative growth between the culture day (D) and shell length (SL) was expressed by the following simple formula from D-shaped veliger to metamorphosing stage; SL = 13.300D + 209.36($r^2$= 0.9078).