• Research in Plant Disease
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• v.7 no.1
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• pp.42-48
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• 2001

The effect of cultural, physical and chemical control methods on the population density of Meloidogyne arenaria second-stage juveniles (J2) and on fruit yields of oriental melon was investigated at Seongju Fruit Vegetable Experiments Station, Kyungpook province, Korea, for two years from 1999 to 2000. Crops used in a rotation prior to Oriental melon were rice, corn, sesame, and green onion. The physical methods used were either solarization, soil addition or soil drying, and a nematicide, fosthiazate of granular formula, was used as the chemical method, applying at a rate of 300g a. i./10 a. Growing rice in the rotation, solarization, and soil addition controlled the nematode disease most effectively, reducing the number of J2 by 90% and increasing fruit yields two times. However, the effects of these control methods on the J2 population were limited to the early growing season; the J2 population increased later, suggesting that additional control practices may be needed in the following season. The next effective control methods were use of corn in the rotation, the nematicide application, and soil drying. The nematicide application was effective only for the early fruit yield, but neither for the late nor for the total yields. Use of sesame or green onion in the rotation was not effective in controlling the nematode.

• Horticultural Science & Technology
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• v.33 no.2
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• pp.186-195
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• 2015

This research was conducted to investigate effect the plant growth regulators (PGRs) on the characteristics of fruit and flesh softening, using GA3 and thidiazuron (TDZ) treatments in 'Heukboseok' grapes. The total yield obtained under PGR treatment was 88.3% lower than the target production when a single treatment with $GA_3$ of low concentrations was used, but the expected yield was recovered by combined treatment with TDZ and $GA_3$. When harvested on the basis of color, the harvest rate up to 100 days after full bloom (DAFB) was low with the $GA_3$ single treatment, but was increased by the addition of TDZ, with the second TDZ mixed treatment being particularly effective. The soluble solids content in the PGR-treated samples demonstrated no significant changes after 90 DAFB, while the acidity content decreased rapidly starting from 90 DAFB. Measured on the basis of sugar and acidity content, maturity was reached much earlier in treated fruit than in the non-treated fruit. Firmness was maintained at a higher level until the final harvest time after PGR treatment compared to untreated grapes according to epidermis thickness and flesh density increase to activity cell division and expansion by $GA_3$ and TDZ. In particular, the fruit quality was improved based on the delay of softening in primary and secondary treatments of $25mg{\cdot}L^{-1}\;GA_3+2.5mg{\cdot}L^{-1}$ TDZ. The production of seedless fruit was difficult, even with the inclusion of TDZ, reaching the highest seedless rate of only 65.5%. Fruit cracking was rare, occurring at a rate of about 0.0~0.9% in all treatments. Accordingly, 'Heukboseok' grapes should be harvested within 100 days after full bloom (DBFB) before a rapid decrease of firmness, conferred by primary and secondary treatments with $25mg{\cdot}L^{-1}\;GA_3+2.5mg{\cdot}L^{-1}$ TDZ.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.28-35
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• 2020

This study is to compare irrigation efficiency between sap flow sensor automated system (SF) and conventional irrigation system based on integrated solar radiation automated system (ISR) in tomato rockwool hydroponics. Total irrigated volumes was higher in the ISR system by 5.0L per plant, a lower drainage rate was found in the SF system, compared to the ISR system. There was no difference in shoot and fruit fresh weights, water use efficiency (WUE) and water amount consumed for producing 200g of tomato fruit. The daily average sap flow density (SFD) was closer to the change of solar irradiance (SI) in the plant grown under the SF system, compared to the ISR system. The correlation coefficient (r²) between the fruit diameter and the volumetric water content during the 56 and 82 days after transplant showed the SF treatment was higher than the ISR at night and daytime, and the correlation was higher at night time. The sap flow density and humidity deficit (HD) of SF treatment was related as closely as the solar irradiance. Further studies should demonstrate that SF irrigation system is a convenient method for hydroponic farmers with advantages, such as growth, higher yield, WUE, and accuracy.

• Journal of Bio-Environment Control
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• v.25 no.4
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• pp.294-301
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• 2016

This study was conducted to analyze the seedling quality of korean melon and the growth after transplanting of korean melon nursed under the LED sources. LED sources were RB7 (Red:Blue=14:2), RB3 (Red:Blue=12:4) and Blue(B=16). Photosynthetic photon flux density(PPFD) was 50, 100 and $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. The lighting treatment was started after graft-taken and was applied for 20 days at 4 hours(05:30 and 07:30, 17:30 and 19:30) per day. Plant height and stem diameter of scion were longer and thicker under a high ratio of blue light condition. Dry matter ratio and compactness were highest in RB3 compared to the other LED sources treatments. $CO_2$ exchange rate increased $5.44{\mu}molCO_2{\cdot}m^{-2}{\cdot}s^{-1}$ under RB7 $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and dropped to negative values under control. PPFD $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ of RB3 resulted in the longest plant height by 132.3cm and flowering ratio also was the highest by 75%.

• Korean journal of applied entomology
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• v.51 no.2
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• pp.91-97
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• 2012

The dispersion indices, spatial pattern and sampling plan for pink citrus rust mite (PCRM), Aculops pelekassi, monitoring was investigated. Dispersion indices of PCRM indicated the aggregated spatial pattern. Taylor's power law provided better description of variance-mean relationship than Iwao's patchiness regression. Fixed-precision levels (D) of a sequential sampling plan were developed using by Taylor's power law parameters generated from PCRM on fruit sample (cumulated number of PCRM in $cm^2$ of fruit). Based on Kono-Sugino's empirical binomial the mean density per $cm^2$ could be estimated from fruit ratio with more than 12 rust mites per $cm^2$: $ln(m)=4.61+1.23ln[-ln(1-p_{12})]$. To determine the optimal tally threshold, the variance (var(lnm)) for mean (lnm) in Kono-Sugino equation was estimated. The lower and narrow ranged change of variance for esimated mean showed at a tally threshold of 12. To estimate PCRM mean density per $cm^2$ at fixed precision level 0.25, the required sample number was 13 trees, 5 fruits per tree and 2 points per fruit (total 130 samples).

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.4
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• pp.405-411
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• 1999

Growth responses and yields of cucumber, the populations of soil microorganisms, and the control value of nematodes were examined with six different treatments of chemical fertilizer, compost, microbial fertilizer(MF), and the combined applications of NPK + MF and compost. Cucumber, Eunseong Bakdadaki cultivar, was cultivated in the greenhouse. Higher plant height was appeared with treatments of the combined application of NPK + compost and NPK + MF compared to other treatments, especially at the early growth until 20th day after transplanting. Also, higher number of opened flowers showed with the combined treatments of NPK + compost and NPK + MF than those with others. The control value of nematodes at 60th day after transplanting with treatments of MF and NPK + MF was about 39.0% and 61.6%, respectively. The density of soil microorganisms was higher in order of actinomycetes, bacteria, and fungus. Their densities were not clearly different with treatments. Fruit yields of cucumber with treatments of NPK, compost, microbial fertilizer, and additions of compost and microbial fertilizer to NPk were higher, about 40 to 60%, than that with the control. The highest fruit yield was with NPK + MF and next highest fruit yield was with NPK + compost. It is assumed that the combined application of chemical fertilizers, compost, and microbial fertilizers would be increased the plant productivity.

• Nutrition Research and Practice
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• v.1 no.4
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• pp.328-334
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• 2007

The purpose of this study was to examine the relationship between nutrient intake and bone mineral density (BMD) of elderly women in Daegu, Korea. In this study, the bone mineral densities of 101 elderly women in Daegu were measured, and their nutrient intake, dietary habits, and maternal factors were determined through a survey. The subjects were divided into the normal group, the osteopenia group, and osteoporosis group to find out if there is a correlation between bone mineral density and maternal factors, dietary habits, and nutrient intake through their T-scores, analyzed according to the standards of WHO. Classification by T-scores of the participants were the normal group 25.7%, the osteopenia group 39.6%, the osteoporosis group 34.7%. Menopause age of the osteoporosis group was lower, postmenopausal period was longer, and last delivery age was significantly higher than the normal group (p<0.05). Osteoporosis group had a lower percentage of 'everyday' fruit and vegetable intakes and higher percentage of 'never' dairy intake than of the normal group. Vitamin A, vitamin $B_1$, and vitamin $B_2$ intakes of participants in the osteoporosis group were lower than those in the normal group (p<0.05). In conclusion, nutritional education is necessary to encourage high intake of milk and vegetables and fruits along with calcium, vitamin A, $B_1$, and $B_1$ intakes and low intake of sodium for the prevention of elderly women's osteoporosis.

• Fisheries and Aquatic Sciences
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• v.24 no.3
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• pp.121-128
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• 2021

The variations of morphological features, density and biomass of vegetative shoots and characteristics of reproductive shoots of Zostera caespitosa were examined in Tongyeong, Korea. Morphological features such as leaf length, width and sheath length of Z. caespitosa showed significant seasonal variation (p < 0.001). The highest aboveground value was recorded in late spring to summer and the lowest value in winter. Density and biomass also showed seasonal variations. Annual average shoot density and biomass of Z. caespitosa were recorded as 1,223.4 leaf m^-2 and 5,956.9 g w.w.m^-2, respectively, and had the highest value in June and lowest values in November and January. Reproductive shoots were observed from April (13℃) to June (21℃). Pistils erected outside sheath, anther dehiscing and small embryos were found in April. Mature fruit and released seeds were found in May and June. These results suggest that this species had a high growth rate in late spring and early summer (15℃-20℃). Reproductive shoots of Z. caespitosa may initially appear at about 10℃ in spring and seed have been released at about 20℃ in fall.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2006.05a
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• pp.229-234
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• 2006

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2006.05a
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• pp.235-241
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• 2006