• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.261-265
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• 2008

This study was carried out to investigate the effects of stem cutting ages and harvest time on the growth and yield of potato 'Dejima' in aeroponics. The stem cuttings were produced from in vitro plantlets and transplanted into an aeroponic system with 20, 30, 40 and 50 day-old stem cuttings (DOS). Tubers were harvested 60, 70, 80 and 90 days after transplanting (DAT) and sorted into following categories: $1{\sim}5$, $5{\sim}10$, $10{\sim}20$, $20{\sim}30$, $30{\sim}40$ and over 40 g. Plant height from the 40 DOS was the highest during the growing periods but no significant difference was observed on 75 DAT. The tuber weight increased until 90 DAT with the greatest weight of tubers in the 20 and 40 DOS. However, there was no significant difference among 20, 30 and 40 DOS in the number and weight of tubers. Harvesting at 80 and 90 DAT increased the number of tubers over 5 g, which are usually considered as appropriate for direct field planting.

• Journal of Korean Society of Forest Science
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• v.95 no.6
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• pp.729-734
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• 2006

This paper aimed to suggest decision-making method for forest management planning using integer programming. Thus, the study examined 85 stands consisting of Korean pine, Japanese larch and oak stands-all of which were at the most suitable time for tending, selection thinning, commercial thinning and final cutting-in the experimental forest of Kangwon National University. The forest management model comprised one objective function, maximizing harvest volume in each stand according to tree species and the kinds of practices, and seven constraints: frequency and stands of practices, minimum and maximum yields, even yields, maximum production, and decision-making varialbes. Besides, the entire period intended by the study was 10 years, divided into 5 management periods. In conclusion, the forest management planning model using integer programming proved that among 85 stands, forest practices were conducted over 68 stands (202.8 ha), producing the total harveted volume of $20,000m^3$, while the rest was reserved. This case study could help make decisions on whether and when the forest practices and harvests could be done in a specific condition.

• Research in Plant Disease
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• v.23 no.3
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• pp.256-261
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• 2017

The effects of insecticide and fungicide treatment were investigated to reduce mycotoxin contamination of corn (Zea mays L.) seeds. Deoxynivalenol and zearalenone contents were reduced in the treated seeds, but aflatoxin, ochratoxin A, fumonisin, and T-2 toxin were not effective by chemical treatments. The chemical treatment did not affect the growth of saprophyte, but inhibited the pathogenic fungi such as Fusarium verticillioides, F. graminearum and F. equiseti. Myotoxin contents at different harvesting time were compared. As the harvest time was delayed, both levels of deoxynivalenol and zearalenone and frequency of Fusarium spp. increased. However, the major nutrient contents of corn seeds were not affected by harvesting period. These results show that chemical treatments are necessary to reduce the fungal contamination of corn and harvest without delay is important as well.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.5
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• pp.307-314
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• 2006

Elevation differences within a paddy field relate strongly to plant health, crop homogeneity, and pest control. For precision agriculture (PA), the elevation within a field should be precisely controlled. We analyzed variation in elevation within two rice paddies over one crop cycle. The study took place in two rectangular plots (Field A and Field B, each $50m{\times}30m$). Elevations within the two plots were measured by a laser-equipped surveying instrument, that could determine elevations to precisions of 1 mm. The test fields were divided into grids with 30 squares; elevation was measured at the center of each $5{\times}10-m$ grid square. This study measured elevation during nine observation periods from pre-plowing to post-harvest. Descriptive statistics showed the highest elevations after plowing due to soil disturbance. One-way analysis of variance (ANOVA) revealed significant elevation differences before and after plowing and transplanting, although elevations were similar over the period of crop growth. Comparison of pre-plowing and post-harvest data showed differences in elevations, indicating that elevation changes occurred during plowing, rice transplanting, plant growth, and harvesting. In summary, the above statistical analyses indicated that elevation changes occurred due to plowing but not during the plant growth season or due to harvesting.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.429-433
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• 2010

The effects of 1-methylcyclopropene (1-MCP) for controlling ripening processes such as weight loss, fruit softening, soluble solids content (SSC), titratable acidity (TA), and fruit skin color were investigated and also the possibility that 1-MCP can inhibit the development of brown rot was explored in 'Formosa' plum ($Prunus$ $domestica$ L.). Fruit were treated with $1{\mu}L{\cdot}L^{-1}$ 1-MCP on the day of harvest and one day after harvest for 16 h at ambient temperature ($20^{\circ}C$), followed by 14 days of shelf life. 1-MCP treatment delayed fruit softening, weight loss and changes in skin color and TA during the shelf life period, but did not affect SSC. These 1-MCP effects were similar with and without delayed treatment. 1-MCP treatment inhibited the development of brown rot caused by $Monilinia$ $laxa$ during storage. Our data shows that treatment delays of ${\geq}1$ day before 1-MCP application had no negative effect of fruit softening, fruit skin color, and TA at ambient temperature ($20^{\circ}C$). Overall, these results indicate that 1-MCP can be used to maintain the quality of non-refrigerated plums.

• Korean Journal of Weed Science
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• v.16 no.1
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• pp.8-13
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• 1996

This study was conducted to know the effect of storage period, harvesting time and light condition on dormancy breaking of major weeds. Echinochloa crus-galli, Cyperus serotinus, Aeschynomene indica, Ludwigia prostrata and Bidens tripartita had the 10 or 30% germination ability within 30 days after harvest but scirpus juncoides, Potamogeton distinctus, Aneilema japonica and Monochoria vaginalis had not germination untill 120 days after harvest of seed. C. serotinus and P. hydropiper required strong light for germination but S. juncoides, L. prostrata and B. tripartita showed the less tham 5% germination in the dark condition gerntinator. S. juncoides germination showed negative response in chemical soaking but A. japonica, B. tripartita and L. prostrata showed high germination percentage in Acetone, Chloroform and distilled water soaking during the 10 days after treatment.

• Food Science and Preservation
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• v.14 no.6
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• pp.565-570
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• 2007

Changes in the quality of Hallabong tangor during growth stage and with temperature pre-treatment after harvest were investigated. Soluble solids of Hallabong increased continuously until early December. The acid content of M16A, a variant species of Hallabong, decreased by 1% after October and continued to decrease until the middle of January. After ripening, treatment to reduce the acid content was required. Fruit firmness decreased gradually until November and was maintained at 1000 g-force after this time. Soluble solids and acid content were $13.3{\pm}0.83^{\circ}Brix$ and $1.07{\pm}0.52%$. Soluble solids increased in temperature-treated Hallabong with prolonged storage, but acid content did not decrease. Fruit firmness also decreased with storage period, regardless of temperature pre-treatment. Therefore, water management during cultivation, temperature treatment above $35^{\circ}C$ after harvest, and checking of the acid content and soluble solids with prolonged storage are recommended in achieving high quality Hallabong.

• Korean Journal of Plant Resources
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• v.28 no.4
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• pp.391-399
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• 2015

There has been little research on the harvesting time-dependent changes in the antioxidant activities of new varieties of highland cultures of Gomchwi (Ligularia fischeri) crossed with Turcs (Ligularia fischeri (Ledeb.)) and Nakai (Ligularia fischeri var. spiciformis), namely Sammany (S), Gommany (G) and Damogy (D). This study was conducted to assess the effect of different harvesting times on nutritional and health-related properties such as total phenolic contents, flavonoids, DPPH (1,1-diphenyl-2-picrylhydrasyl) free radical scavenging activities and reducing power. From these harvests, extracts were prepared using methanol. Total phenolic content in Jul 14-G (Gommany harvested on July 14, 0.172 ㎎·GAE/ml) was higher than that in other products harvested after the same period (S, 0.154; D, 0.141 ㎎·GAE/ml). Flavonoid content was higher in Jul 3-G (0.114 ㎎·QE/ml), compared to Jul 3-S (0.113 ㎎·QE/ml) and Jul 14-D (0.089 ㎎·QE/ml). Antioxidant activities were higher in samples harvested after June 12 in all cases. On July 14, the highest DPPH free radical scavenging activities among all harvest dates were seen (92.875~94.595%). The reducing power was also dependent on harvest day (Abs 0.5~0.6 on July 14), showing a pattern similar to that of DPPH free radical-scavenging activities. Antioxidant activity and harvesting times seem to correlate with total polyphenol and flavonoid contents.

• The Korean Journal of Pesticide Science
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• v.17 no.1
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• pp.6-12
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• 2013

Methoxyfenozide and novaluron were sprayed with single and triple treatments separately on peach during cultivation period. Samples were collected over 14 days, 8 times in total (0, 2, 4, 6, 8, 10, 12, 14 days). Methoxyfenozide and novaluron were extracted with acetone and partitioned with dichloromethane, and analyzed by HPLC/DAD. Method Quantitation Limit (MQL) were both 0.005 mg/kg, average recoveries of methoxyfenozide at two fortification levels of 0.05 and 0.25 mg/kg were determined $92.7{\pm}2.9%$ and $102.8{\pm}3.1%$, and novaluron were $98.2{\pm}4.8%$ and $96.7{\pm}9.0%$, respectively. The biological half-life of methoxyfenozide was about 4.41 days at single treatment, and 4.24 days at triple treatments. The biological half-life of novaluron was about 14.81 days at single treatment, and 14.50 days at triple treatments. Dissipation of pesticides on peach was influenced by growth dilution effect. In case of application of methoxyfenozide and novaluron following guidelines on safe use of pesticides, the final residue level was predicted to be lower than Maximum Residue Limit (MRL).

• Journal of Mushroom
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• v.10 no.4
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• pp.160-166
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• 2012

The effects of fixed and variable temperatures on fruiting body formation and characters of mushrooms were investigated with normal and thinning treatment plots. In fixed temperature, as temperature was lower, period of harvest was longer as well as days for pinheading in the both of normal and thinning plots. Harvest rate were 91.0, 90.3, and 95.8% at $13^{\circ}C$, $17^{\circ}C$, and $15^{\circ}C$. In the thinning plot, qualities of mushrooms were 7.5, 8.1, and 7.7, and yields were 86.0, 105.9, 104.0g at 13, 15, and $17^{\circ}C$ respectively. In variable temperature with a variable temperature plot, condition II($17^{\circ}C$ for pin-heading(before reverting, 7-8 days)${\rightarrow}16^{\circ}C$ for extending primodia(before thinning, 4-5 days)${\rightarrow}15^{\circ}C$ for extending (after thinning)) was the best for yield which was better than other conditions by 17.4% and 4.0% and quality of mushroom was highest 8.1 among all conditions.