• Journal of Practical Agriculture & Fisheries Research
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• v.13 no.1
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• pp.35-46
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• 2011

The effects of organic calcium agent(ECa) tree-spray on the mineral nutrition concentration of petiole and fruit skin and quality in grapevines were studied. The calcium concentration of petiole and fruit skin at harvest in 'Campbell Early' by tree-spray after flowering 14days of calcium agent were increased significantly in calcium chloride 0.4%, ECa 250X and MCa 500X compared to control. The calcium concentration of petiole and fruit skin at harvest by ECa tree-spray after 7 days and 14 days flowering were increased significantly compared to control and 21 days after flowering treatment. Also, The calcium concentration of petiole and fruit skin at harvest by tree-spray of ECa 250X and 125X after flowering were increased significantly compared to control and 500X treatment. Fruit quality, fruit cluster weight, cracking fruit and Bitter rot occurrence by ECa tree-spray of treatment time and concentration different showed no difference between control. Phytotoxicity by tree-spray of ECa concentration different not occur to leaf and fruit.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.343-349
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• 1993

This study was conducted 1)to determine the factors responsible for the gradually increased rice yield by examining any improvements in yield-related characters and physiological characters among the historically recommended varieties of rice in Korea, and 2)to reveal the way of achieving further yield improvement by breeding in the future. Eight recommended varieties from 1911 to 1988 were selected and grown at the same conditions. The yield-related characters were observed at the harvest time, and the physiological characters such as RGR, NAR, LAR, SLA and L WR were estimated by the classical method of growth analysis. The newer varieties are shorter and those released after 1970's are greater in percent of filled spikelets and harvest index than the older varieties. There are no definite changing trends in the variations of number of panicles per hill, number of spikelets per panicle and 1000 grain weight according to the course of evolution in the recommended varieties. There is little evidence of improvement in the physiological characters such as NAR, LAR, SLA and LWR among the recently developed varieties compared with those of the older varieties. The increase in grain yield due to variety improvement, if any, is largely associated with the greater harvest index and percent of filled spikelets by breeding blight resistant and / or lodging resistant genotypes with short culm. It is suggested that increase in NAR should be carried out simultaneously with increase in harvest index to breed high yielding genotypes. I t appears to be important to breed genotypes with long culm in order to enhance light penetration into the canopy as long as they are lodging resistant. Since NAR is negatively correlated with LAR, it is unlikely to succeed to improve both characters simultaneously. The direct effect of NAR on RGR by path analysis is much larger than that of LAR, and hence it is suggested that breeding genotype with large NAR is more effective on enhancing RGR. It is also suggested that improving LAR through LWR is likely effective on increasing RGR.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.3
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• pp.176-180
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• 2000

The higher sugar and lower starch in super sweet corn may be due to modified endosperm genes sh, bt series, but its seeds have major limiting factors causing low germination and low seedling vigor, This study was conducted to determine what measurable kernel characteristics during the grain tiling period might be more useful as a guide to optimize harvest date for good seed quality in hybrid super sweet corn production. Artificial crossing in super sweet corn hybrid (Chodangok 1) was made on the same day, and ears were harvested from 18 days to 53 days after pollination at weekly intervals. Kernel weight, moisture content, hardness, endosperm rate, seedling height and storage nutrients such as sugars, protein, starch, and germination rate were measured for the kernels at each harvest. Super sweet corn hybrid, Chodangok 1 presented satisfactory germination rate above 70% when harvested on 39 to 46 days after pollination. Its storage nutrients at that time were 23.7-24.2% in starch content 5.5-5.9% in total sugars, 38.9-46.6% in kernel moisture, and 62.7-64.2% in endosperm rate. Germination rate was extremely high when harvested on 39 days after pollination. The black layer of Chodangok 1 could not be used as an indicator for seed harvest. These results suggested that optimum harvest date seems to be 39 days, and kernel moisture and starch content could be used as indications of kernel maturity in deciding when to harvest fer good seed quality in super sweet corn.

• Horticultural Science & Technology
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• v.34 no.4
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• pp.644-654
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• 2016

Supervised residue trials for mandipropamid in Korean cabbage(Brassica campestris L.) were conducted to establish its pre-harvest residue limit (PHRL), a criterion to ensure the safety of the terminal pesticide residue during cabbage production. Tissues of Korean cabbage were collected at 0, 1, 3, 5, 7, and 10 days after mandipropamid application and subjected to residue analysis. The analytical method was validated by recoveries ranging from 88.2-92.2% at two levels (0.4 and $2.0mg{\cdot}kg^{-1}$), and a limit of quantitation (LOQ) of $0.04mg{\cdot}kg^{-1}$. Mandipropamid residues in Korean cabbage gradually decreased over time. The dissipation rate of the residue would be affected by intrinsic degradation of the compound along with dilution resulting from the fast growth of Korean cabbage. The decay pattern was well fitted by simple first-order kinetics. Biological half-lives of mandipropamid in Korean cabbage ranged from 3.9-4.0 days in two field conditions. Calculated by the regression curve of mandipropamid dissipation, the PHRLs of mandipropamid in Korean cabbage were recommended as 11.07-12.19 and $5.76-6.05mg{\cdot}kg^{-1}$ for 10 and 5 days prior to harvest, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.104-107
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• 2005

This survey was conducted to know the post-harvest bulk treatment system for barley, The tendency of barley-bulk treatment in 4 RPC was gradually increased up to 4,458 ton in 2001, but after that time, the amounts was decreased 1,0731on in 2003. There was the big difference on the circulated and the continued systems that was the kinds of drying system they use. The barleys, the harvest and the conveyance method was different on RPCs. Naked barley was only treated, and $90\%$ barley was harvested by the consignment in J RPC, otherwise unhulled barley was treated, and there did not used the consignment in S RPC. Small and mulit combine was used to harvest, and the ratio of bulk was up to $90\%$ in J RPC, but small combine was only used and ratio of bulk was at most $5\%$ in S RPC. It was sell by 1kg in polished and 40kg unpolished barley around year in J RPC, but it was sell by bulk to september in S RPC.

• Journal of Biosystems Engineering
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• v.42 no.4
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• pp.276-282
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• 2017

Purpose: This paper presents the effects of soil drought stress during the growing season and pre-harvest period on tree growth and fruit quality of "Yumi" peach, an early season cultivar. Methods: Soil drought stresses were treated with four levels of -30, -50, -60, and -70 kPa during long term (LT) and short term (ST). For LT treatments, soil water was controlled for nine weeks from May 1 to July 5, which was assumed as the full growing season. For ST treatments, soil water was controlled for four weeks from June 10 to July 5, which was assumed as the pre-harvest season. Tree growth and leaf photosynthesis were measured, and fruit characteristics such as fruit weight and diameter, soluble solid and tannin contents, and harvest date were investigated. Results: Soil water deficit treatments caused a significant reduction in tree growth, leaf photosynthesis, and fruit enlargement. LT water stress over -60 kPa during the full growing season caused significant reduction in tree growth, including shoot length, trunk girth, leaf photosynthesis, and fruit enlargement. ST water stress over -60 kPa during the pre-harvest period also induced significant reduction in leaf photosynthesis and fruit enlargement, while tree growth was not reduced. In terms of fruit quality, water stress over -50 kPa significantly reduced fruit weight, increased soluble solid and tannin contents, and delayed harvest time in both LT and ST treatments. Conclusions: As a result, it is assumed that LT water stress over -60 kPa can reduce both tree growth and fruit enlargement, whereas ST water stress over -50 kPa can reduce fruit enlargement without reducing tree growth. From an agricultural perspective, moderate water deficit like -50 kPa treatments could have positive effects, such increased fruit soluble solid contents along with minimal reduction in fruit size.

• Korean Journal of Environmental Agriculture
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• v.34 no.3
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• pp.223-229
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• 2015

BACKGROUND: It is important to understand residual patterns of pesticides applied on crops for ensuring their safety in agricultural products. However, there are few studies on the residual patterns of pesticides in minor crops, which are small in cultivation area. In this study, residual amounts of bifenthrin and chlorfenapyr sprayed on perilla leaf as a minor crop were investigated to know their residual patterns. METHODS AND RESULTS: Bifenthrin and chlorfenapyr were sprayed 2 or 3 times on perilla leaves at a week interval prior to harvest, and the perilla leaves were collected at 0, 1, 3, 5 and 7 days after the final application of pesticides. Recoveries for residual analysis of pesticides spiked on perilla leaves with concentrations of 0.1 and 0.5 mg/kg were 81.9-104.8%. The residual amounts of pesticides interpreted using first order kinetics model show that dissipation constants of bifenthrin and chlorfenapyr in perilla leaves were 0.0724-0.0535 and $0.0948-0.0821day^{-1}$, respectively. In addition, the dissipation half-lives in perilla leaves were 9.6-12.9 days for bifenthrin and 7.3-8.4 days for chlorfenapyr. When pre-harvest residue limits (PHRL) of bifenthrin and chlorfenapyr at 10 days before harvest calculated on the basis of the dissipation constants and maximum residue limits of the pesticides were calculated as 17.1 for bifenthrin and 15.9 mg/kg for chlorfenapyr. CONCLUSION: Therefore, the PHRL calculated using the time-dependant residual patterns of pesticides in perilla leaves and their regression analysis may be used as experimental evidences in order to ensure the safety of pesticides in perilla leaves before harvest.

• Korean Journal of Weed Science
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• v.13 no.1
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• pp.7-13
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• 1993

Experiments were carried out to investigate the utilization of paraquat and diquat as desiccants for harvest-aid of sesame. When paraquat and diquat were sprayed at 3days or 3hours before cutting of sesame plants, moisture content in treated plots was evenly rapidly decreased and sesame yeild was not significantly different as compared with that in untreated plot. Percentage of germination of sesame seed in treated plots was similar to that in untreated check. Residual amount in sesame seed was not detectable when these chemicals were treated with 250ppm at 3days before cutting of sesame plant. Percentage of thrashing was high in sesame plants treated with paraquat and diauat with the lapse of time after cutting. Required labor in thrashing of sesame was reduced when applied with these chemicals. Harvest efficiency of sesame after spray of paraquat and diquat was good by comparison with the traditional practice.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.203-206
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• 2005

TGE (Transmissible Gastroenteritis) caused by a virus belonging to family coronavirus, results in an acute infection of the small intestine of the pig. The optimum operation variables such as multiplicity of infection (MOI), infection time and harvest time were investigated for TGE vaccine production by immobilized ST(swine testicle) cells. In the culture supplemented with 5% serum, maximum virus titer of $1.2{\times}10^6pfu/ml$ was obtained at the conditions of 0.01 MOI, 2day infection time, and 1 day harvest time. Serum is a potential source of bacterial, mycoplasmal and viral contamination, and it has a possibility of the introduction of serum proteins, prion and pyrogens into the final product. For these reasons, much attention has been focused on the development of serum-free media. A new serum-free media (SFM) has been developed in order to produce TGE vaccine of high quality with low cost. The performance of SFM developed was compared with other commercially available serum-free media and serum supplemented media in terms of virus productivity. The cultures with serum-free media showed higher titer than that with serum supplemented media. Among various serum-free media tested, CHO-S-SFMII showed highest virus titer.

• Korean Journal of Medicinal Crop Science
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• v.4 no.2
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• pp.163-171
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• 1996

The influences of temperature, harvest time, sowing time, seeding media, moisture content of media and light on the seed germination of Lycoris are as follows, Both L. koreana and L. aurea had over 90% seed setting, and seed maturity came in September or early October. It took six months to have over 60% seed germination. The optimum germination temperature was $25^{\circ}C$, and the alternating treatment was effective at $20{\rightleftarrows}25^{\circ}C$. The optimum harvest-time was around Sep. 20, and the optimum seed-time was immediately after havest. The optimum seeding media was sand loam, and the optimum moisture content was PF 1. 9/400ml seeding media. The dark condition was more effective for the seed germination than the light condition.