• Research in Plant Disease
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• v.22 no.3
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• pp.208-212
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• 2016

During the nursery seedlings stage at Muan in 2013, moisture and temperature conditions were favorable for the occurrence of onion downy mildew. Several fungicides were evaluated for controlling onion downy mildew at the stage of seedling. The disease incidence of the untreated control was 51.1%, which was sufficient to evaluate the fungicide efficacy for the control of onion downy mildew. Incidence at the mancozeb treatment (MAN treatment) was 4.4% and it was the highest control value of 91.4%. Incidence at the various fungicides treatment (MIX treatment) consisted of amectotradin plus dimethomorph, floupicolide plus propamocarb HCl, or dimethomorph plus pyraclostrobin was 10.0%, and the control value of the MIX treatment was 80.4%. Among the tested fungicides, amectotradin plus dimethomorph (AME plus DIM treatment) was selected and treated. Incidence of AME plus DIM treatment was 12.2%. There was statistically significant difference among the three different treatments and the untreated control. These results suggest that the application of fungicides on onion nursery seedlings was effective to control the onion downy mildew.

• Korean Journal of Organic Agriculture
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• v.20 no.1
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• pp.49-58
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• 2012

Greenhouse whitefly, $Trialeurodes$ $Vaporariorum$, is the most important insect pest in environmental friendly tomato production. Natural enemies, $Nesidiocoris$ $tenuis$ and environmental friendly agricultural materials (EFAM) are major control agents in Korea. The aim of the present work is to evaluate release time of $N.$ $tenuis$ in controlling of $T.$ $vaporariorum$ and to select environmental friendly agricultural materials (EFAM) to suppress both $T.$ $vaporariorum$ and $N.$ $tenuis$ which if the density were high causing necrotic rings. Six EFAM selected to control of $Trialeurodes$ $Vaporariorum$ in three times spray with seven days intervals. Three EFAM showed high mortality 67.7-70.5% in spray after release plot but low in release after spray plot. It should be careful to spray with $N.$ $tenuis$. When $N.$ $tenuis$ were early release at 7 days after transplanting which before occurring and establishment of greenhouse whitefly, it could suppress the density. Extracts of bead tree + matrin, matrin 1, Chrysanthemum showed high mortality on $T.$ $vaporariorum$ adults and $N.$ $tenuis$. The results suggested that this three EFAM could be control agents of the damage of necrotic rings from $N.$ $tenuis$.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.3
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• pp.205-214
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• 2020

In this study, we performed to evaluate the water balance during the cultivation of Chinese cabbage and maize according to the soil type and water management method using weighable lysimeters, and to estimate the crop water stress coefficient and minimal water requirement by considering crop productivity and water deficiency. In 2018, Chinese cabbage cultivation period was not irrigated due to frequent rainfall two weeks after planting, so there was no difference in irrigation amount between the non-irrigated and the irrigated and little difference in crop yield. Excluding the Chinese cabbage cultivation in 2018, in the cultivation of Chinese cabbage and maize, the crop yield of irrigated plots was higher than that of non-irrigated plots. The evapotranspiration of irrigated plots was also generally higher than non-irrigated plots. Crop yield and evapotranspiration are closely related, and transpiration is active as biomass increases. The crop water stress coefficients in the middle and the late stage were 0.8 and 0.8 for Chinese cabbage and 0.8 and 0.5 for maize, respectively. The minimal water requirements for Chinese cabbage and maize were 82.0% and 68.8%, respectively, compared to the optimal water requirements (239.4 mm for Chinese cabbage and 466.9 mm for maize). These results can be used as basic data for water management for crop cultivation by securing the minimum amount of irrigation in case of water deficiency.

• Korean journal of applied entomology
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• v.41 no.4
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• pp.293-298
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• 2002

Cadusafos and fosthiazate were applied at the rate of 1.8 g a.i./6$\m^2$ as pre-plant or pre-plant＋post-plant treatments on winter-grown oriental melon in a greenhouse soil infested with Meloidogyne arenaria. Nematicides reduced root-knot nematode population from 35 to 90% compared with control； fosthiazate was better than cadusafos (P ＝ 0.003) and fosthiazate pre-plant＋post-plant application reduced nematode population densities as much as 90%. Nematicides increased yield in an average of 23% (11-38%) in May, 39% (2-65%) in June, and 31% (12-46%) for the total (P ＝ 0.085). The residue in the fruit of oriental melon by post-plant treatment of fosthiazate exceeded maximum residue limit of 0.2ppm, while the Cadusafos residue was below the limit. It is concluded that fosthiazate cannot be used as a post-plant treatment in winer-grown oriental melon with overall consideration, i. e., danger of residue, value of melon, costs of nematicide, consumer demand on safer agricultural products, and effects of fallow.

• Korean journal of applied entomology
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• v.46 no.3
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• pp.409-414
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• 2007

Economic injury levels and economic thresholds were estimated for the american serpentine leafminer (Liriomyza trifolii) on greenhouse eggplant. Liriomyza trifolii density was increased until the late June and decreased after the July in innoculation on may 17. Growth of an aerial plants and fruits were not different in treatment respectively. But total number of fruits and yields were decreased on higher inoculation density. Whereas the rate of yield loss was increased. The rates of damaged leaf by L. trifolii were increased on higher inoculation density and the peak was 65%. The number of commodity fruits and the rates of commodity fruit were become lower than non-treatment (72.2%). The rates of damaged leaf area were 5.3, 11.7, 19.7, 25.7% on inoculation densities and the rates of yield loss were 0.6, 4.8, 9.8, 14.7%, respectively. There existed close correlation between rate of yield loss and inoculation density (Y = 0.76779X + 0.298354, $R^2\;=\;0.9599$). Considerated of the results, the economic injury levels of L. trifolii on eggplant greenhouse was 6.1 adults per 4 plant and the economic thresholds was 4.9 adults per 4 plant.

• The Korean Journal of Mycology
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• v.31 no.3
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• pp.200-205
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• 2003

The study was carried out on the artificial cultivation of the abalone mushroom, Pleurotus cystidiosus O.K.Miller. The pine sawdust substrates with 20% rise bran were good for mycelial growth and high quantity of P. cystidiosus in the bottle cultivation. Moreover, the proper volume for bottle cultivation was 850 ml and the removal of spawn and surface layer of the medium before pin-heading was more efficient. The yields of P. cystidiosus were higher in sawdust substrates added calcium carbonate than those not added calcium carbonate. The volume of 3 kg polypropylene bag is good for yield and biological efficiency in bag cultivation of P. cystidiosus. Cotton wastes were proper substrates for bag cultivation. In the effect of different cultivation temperature, $28{\pm}2^{\circ}C$ cultivation temperature was good for for primordial formation after inoculation.

• Journal of agriculture & life science
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• v.44 no.5
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• pp.23-27
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• 2010

The control of stem length is most important external quality aspect in cut chrysanthemum. The present work in conducted in growth chamber and aims at investigating the effect of light intensity on the photosynthesis capacity and stem elongation in cut chrysanthemum. To evaluate the effect, different level of assimilation lighting (LEDs) was given to canopy level 60, 100, 140, and $180mol{\cdot}m^{-2}{\cdot}s^{-1}$, individually, under short-day conditions, and the light treatments were initiated from 7days after planting. There was a positive linear-regression relationship between the light intensity and the net assimilation rate. On the other hand, there was not significant difference in flower buds induction. The growth of stem length, leaf area, and dry weight was increased by increasing the light intensity, whereas the plants grown under 140 and $180mol{\cdot}m^{-2}{\cdot}s^{-1}$ was not differences in those of growth. It indicates that the increased net assimilation rate is not continually coincided with the maximized growth in cut chrysanthemum. It might be considered that the optimal light intensity for stem elongation of cut chrysanthemum is $140mol{\cdot}m^{-2}{\cdot}s^{-1}$ under short-day condition.

• FLOWER RESEARCH JOURNAL
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• v.17 no.3
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• pp.172-178
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• 2009

This experiment was conducted to elucidate the proper suppling frequency of nutrient solution for grafted cactus Gymnocalycium mihanovichii var. friedrichii grown hydroponically without medium. Grafted cactus seedlings were planted onto the cultivation bed without medium, using labor-saving tray. The treatments like 1, 3, 5 and 7 times of nutrient solution supply per day and continuous soaking of plant root in the nutrient solution during the daytime were tested in summer and winter season. The growth of grafted cactus was worst in the treatment of one time supply of nutrient solution per day, and there were not significant difference in growth of grafted cactus among other treatments both in summer and winter season. 17.6% of grafted cactus seedlings failed to rooting in the treatment of one time supply of nutrient solution per day in winter season. The proper suppling frequency of nutrient solution, for the grafted cactus Gymnocalycium mihanovichii var. friedrichii grown hydroponically without medium, was three times supply of nutrient solution per day both in summer and winter seasons considering growth and rooting of plants.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.304-311
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• 2021

This Experiment was conducted to determine the effects of light shield materials when melon grown inside a plastic greenhouse in summer season. The average temperatures were 36.6℃, 34.5℃ and 34.0℃ respectively for the control(non-shield), coating agent, and the white net. The light transmittances were 69% and 75%, respectively inside the greenhouse treated with the coating agent and white net immediately after applicants, compared with that inside the control greenhouse. At the 40 and 80 days after treatment, the light transmittances for the coating agent were 92% and 98%, respectively, indicating it was slowly decomposed and removed, but there was no change in the transmittance for the white net. While the leaf number did not differ among the treatments, the plant height was higher in the white net and shading agent than in control. The weight of the leaves, fresh-weight and dry-weight were no different from that of shading, but it became heavier in the later stages. The marketable fruit yield was increased by 6% for white nets and 5% for the coating agent compared to control, there was no statistical significance. Therefore, coating agent is considered as an effective method to lower temperature during high temperature period, but it is preferable to use it in consideration of cultivation period, because the coating agent is gradually removed.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.3
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• pp.15-25
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• 2019

The study was conducted to compare the chemical properties and microbial activity of soil and the crop productivity by applying homemade liquid fertilizers (LF) used in leading cucumber farms as well as to evaluate the eco-friendly LFs to substitute for a chemical fertilizer. Three homemade LFs, EM, starfish, and native microbes, and a chemical LF were regularly fertigated per three days during the growing season. Chemical LF contained the highest pH, EC (electrical conductivity), and concentrations of T-N, $P_2O_5$, K, Ca, and Mg, while the lowest EC level was observed for EM LF. Soil EC was the highest to the 3.0 dS/m for chemical LF-plots, with lowering soil pH, OM (organic matter), and Mg concentration. Soil chemical properties mostly increased in native microbes LF-plots. However, soil microbial properties were not significantly different among the LF treatment plots. OTU (operational taxonomic units), richness estimator, and diversity index of bacteria and fungi increased in the chemical LF and EM LF based on the pyrosequencing analysis. SPAD and PS II values on the treated-cucumber leaves were seasonally decreased from 32 to 60 days after transplanting, with the rapid decline observed at 45 days after transplanting. Number of leaves and crop height increased in the treatments with EM and native microbes LF. LF treated-cucumber crops were not significantly different for total fresh weight and fruit yield.