• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.52-63
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• 1998

A novel quinolineoxadiazoles, substituted the carboxylic acid group with 1,2,4-oxadiazole radicle, of KSC-16960 and related compounds were evaluated to examine the herbicidal activity, crop injury and residual effect of after-vegetable crops compared with those of quinclorac (3,7-dichloro-8-quinolinecarboxylic acid), of which use is now banned because of its residual activity to some succeeding vegetable crops. KSC-16960 showed 2- and 3-leaf stages of barnyardgrasses effectively controlled by more than 95 and 90%, respectively, at a rate of 6.25 g/ha. The dose of KSC-16960 controlled 4- and 5-leaf stages of barnyardgrasses by more than 90% were found to be 50 g and 100 g/ha, respectively. The selectivity of KSC-16960 between direct-seeded rice and barnyardgrass was approximately 2-fold higher than that of quinclorac when they were treated to the soil. The selectivity indices of KSC-16960 and of quinclorac between 1-leaf stage of direct seeded rice and 5-leaf stage of barnyardgrass were 44 and 23, respectively, and those between 1-leaf stage of direct seeded rice and 4-leaf stage of barnyardgrass were almost 2-fold higher. Application of KSC-16960 with bentazone exhibited an additive controlling effect on several weed species, but that of quinclorac exhibited an antagonistic effect. With pyrazosulfuron-ethyl, on the other hand, both application of KSC-16960 and quinclorac showed additive interactions. Under a greenhouse condition, the residual activity of KSC-16960 to succeeding tomato plants was approximately 4-fold lower compared to that of quinclorac. KSC-16960 could be substituted for quinclorac, if it will be made some more improvement for reducing residual activity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.77-85
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• 1995

To develop a simple test for evaluation crop tolerance to acid rain disks of recently matured leaves of 12 crops（rice, corn, barley, wheat, soybean, adzuki bean, Chinese cabbage, radish, lettuce, spinach, and tomato） were soaked in simulated acid rain（SAR） solutions for 1, 2, 3, and 4 hours. Changes in pH and electrical conductivity（EC） of leaf soaked solutions and changes in the color of the soaked leaves were observed. The pH and EC of leaf soaked solutions differed depending on the pH of SAR, crops, and soaking time. Among the crops differences in pH of leaf soaked solutions were most stable and significant for 1∼4 hour soaking in pH 4.0 SAR solution, but those of EC were for 1∼4 hour solaking in pH 5.0 SAR soultions. Color of leaves soaked in pH 2.0 SAR solutions was changed significantly, but not in the pH 3.0 or higher SAR solutions. Vis-ual damages of intact leaves caused by spray of pH 2.0 SAR solution in the greenhouse was posi-tively correlated with pH changes in pH 4.0 SAR solution, but not with EC changes in pH 5.0 SAR solution or color changes of leaves soaked in pH 2.0 soulution. The pH of solution was posi-tively correlated with Ca and Mg concentrations of the solutions and EC was positively correlated with K, Ca, and Mg.

• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.36-45
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• 2001

This study was conducted to search new target enzymes of novel herbicide candidate. Total of 107 biochemical inhibitors reported to inhibit over than 100 different plant enzymes were purchased from commercial chemical companies. 15 inhibitors and 34 enzymes were selected by germination assay, seedling assay, wheat leaf disc assay, and whole plant assay. Among them, seven compounds of purine, phehyl-hydrazine, o-phenanthroline, oleylamine, dicyclohexylcarbodiimide, 7,8-benzoquinoline, and aminooxyacetic acid showed high herbicidal activity in the whole plant assay under greenhouse while 7,8-benzoquinone, 8-hydroxyquinoline, 2,2'-dipyridyl, and o-phenanthroline inhibited seed germination of barnyardgrass, rice, and tomato at concentrations of 1.25 to $5{\mu}M$. The compounds of 7,8-benzoquinoline, chlorpromazine, cyanuric fluoride, 4-methylpyrazole, oleylamine, tranylcypromine, and trifluoperazine inhibited the growth of cyanobacteria at 30 to $100{\mu}M$. The compounds of dicyclohexylcarbodiimide and chlorpromazine exhibited whitening effect on tile wheat leaf disc at $100{\mu}M$. These results suggest that the plant-specific enzyme inhibitors which have biological activities may supply the target enzyme for developing new herbicide candidate.

• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.163-170
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• 2012

Nineteen registered insecticides including 8 mixed formulations with buprofezin and 11 single formulations which is not including buprofezin were evaluated by spray application for their toxicity against adult and nymph of citrus mealybug, Planococcus citri. Five mixed formulations with buprofezin such as buprofezin 15EC+acetamiprid 4EC, buprofezin 10SC+clothianidin 3SC, buprofezin 20WP+dinotefuran 15WP, buprofezin 20SC+thiacloprid 5SC, and buprofezin 20SC+thiamethoxam 3.3SC showed high insecticidal activity (>93%) against nymph and adult of P. citri. Insecticidal activities of EPN 45EC, fenitrothion 50EC and methidathion 40EC in organophosphorous group showed 90 to 93% against nymph only. In addition to, insecticidal activities of acetamiprid 8WP, clothianidin 8SC, dinotefuran 20WG and thiamethoxam 10WG in neonicotinoids group showed above 90% against nymph only. In systemic and residual effect, five mixed formulations that was already proved to have high insecticidal activity showed low toxicity with below 60% against $3^{rd}$ instar nymph of P. citri in tomato and rose under greenhouse. Control efficacy of five mixed formulations with buprofezin was above 90%, 80% and 70% at 5 days after treatment (DAT), 10 DAT and 15 DAT, respectively.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.395-400
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• 2012

In order to survey the actual pesticide usage, this survey was carried out on the growers of 3 plant groups, fruit vegetables, fruits and rice field, from 2009 to 2011. 390 farmers were selected from main production areas to investigate their pesticide application during the growing seasons. Input amounts per area of domestic fruit vegetables was surveyed as 11.6 kg a.i./ha for red pepper of field culture, 2.0 kg a.i./ha for red pepper of greenhouse, 2.3 kg a.i./ha for strawberry, 2.2 kg a.i./ha for watermelon, 4.8 kg a.i./ha for cucumber, 1.5 kg a.i./ha for oriental melon and 2.1 kg a.i./ha for tomato, respectively. Input amounts per area on fruits and on rice field were surveyed as 11.7 kg a.i./ha for apple, 12.5 kg a.i./ha for pear, 7.7 kg a.i./ha for peach, 4.5 kg a.i./ha for grape, 40.0 kg a.i./ha for citrus 5.4 kg a.i./ha for persimmon, and 3.46 kg a.i./ha for rice, respectively. As a result of the actual pesticide usage survey, The safety guideline for pesticide use is generally kept well by all farmers of fruits vegetables, fruits and rice.

• Korean Journal of Environmental Agriculture
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• v.39 no.2
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• pp.106-113
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• 2020

BACKGROUND: Bumblebees have been shown to be very effective pollinators for most greenhouse tomatoes. Neonicotinoid insecticides are one of the most widely used pesticides in tomato crops in Korea. METHODS AND RESULTS: This study was carried out to investigate the toxicity of four neonicotinoid insecticides (clothianidin, dinotefuran, imidacloprid and thiamethoxam) to bumblebees based on the OECD guidelines (No.246, 247). The 48 hr LD₅₀ (㎍ a.i. /bumblebee) values in the acute contact toxicity tests were determined as follows: clothianidin, 0.467; dinotefuran, 3.741; imidacloprid, 3.967; and thiamethoxam, 0.747. The 48 hr LD₅₀ values in the acute oral toxicity tests were determined as follows: clothianidin, 0.005; dinotefuran, 0.056; imidacloprid, 0.325; and thiamethoxam, 0.018. The acute contact and oral toxicity of the test insecticides to bumblebees from most to least toxic was clothianidin > thiamethoxam > dinotefuran > imidacloprid. CONCLUSION: This study provided the basic toxicological data of neonicotinoid insecticides for bumblebees. In the near future, acute toxicity and mixture toxicity of other pesticides to bumblebees could be determined using this method.

• Food Science and Preservation
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• v.20 no.2
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• pp.151-157
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• 2013

This study was conducted to investigate the effect of mature stages on quality of Rafito tomatoes (Lycopersicon esculentum Mill.) during storage at low temperature. Tomatoes grown in greenhouse were harvested at three different mature stages (turning, pink, and red), packaged with a 30-${\mu}m$-thick polyethylene film, and then stored at 5 and $10^{\circ}C$, respectively. The changes in firmness, soluble solids content (SSC), titratable acidity (TA), colour, lycopene content, decay, and chilling injury were measured on a weekly basis. After three weeks of storage, chilling injury and decay were found to have individually occurred at 5 and $10^{\circ}C$, respectively. As there was little change in quality at $5^{\circ}C$, it was concluded that red tomatoes could maintain their good quality for two weeks. The normal postharvest ripening was inhibited in the turning and pink tomatoes during storage at $5^{\circ}C$. The turning and pink tomatoes showed improved quality after two-week storage at $10^{\circ}C$. In particular, the turning fruits showed the highest firmness throughout the storage period. Furthermore, the red colour, SSC/TA, and lycopene content of the turning fruits reached the same levels as with the red fruits after two-week storage at $10^{\circ}C$. These results suggest that red tomatoes should be stored at $5^{\circ}C$ to inhibit decay, and that the optimum temperature for early-harvested tomato (turning and pink) is $10^{\circ}C$ for the ripening process after harvest.

• Journal of Bio-Environment Control
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• v.22 no.2
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• pp.138-145
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• 2013

In order to develop the efficient control algorithm of the two-fluid fogging system, cooling experiments for the many different types of fogging cycles were conducted in tomato greenhouses. It showed that the cooling effect was 1.2 to $4.0^{\circ}C$ and the cooling efficiency was 8.2 to 32.9% on average. The cooling efficiency with fogging interval was highest in the case of the fogging cycle of 90 seconds. The cooling efficiency showed a tendency to increase as the fogging time increased and the stopping time decreased. As the spray rate of fog in the two-fluid fogging system increased, there was a tendency for the cooling efficiency to improve. However, as the inside air approaches its saturation level, even though the spray rate of fog increases, it does not lead to further evaporation. Thus, it can be inferred that increasing the spray rate of fog before the inside air reaches the saturation level could make higher the cooling efficiency. As cooling efficiency increases, the saturation deficit of inside air decreased and the difference between absolute humidity of inside and outside air increased. The more fog evaporated, the difference between absolute humidity of inside and outside air tended to increase and as the result, the discharge of vapor due to ventilation occurs more easily, which again lead to an increase in the evaporation rate and ultimately increase in the cooling efficiency. Regression analysis result on the saturation deficit of inside air showed that the fogging time needed to change of saturation deficit of $10g{\cdot}kg^{-1}$ was 120 seconds and stopping time was 60 seconds. But in order to decrease the amplitude of temperature and to increase the cooling efficiency, the fluctuation range of saturation deficit was set to $5g{\cdot}kg^{-1}$ and we decided that the fogging-stopping time of 60-30 seconds was more appropriate. Control types of two-fluid fogging systems were classified as computer control or simple control, and their control algorithms were derived. We recommend that if the two-fluid fogging system is controlled by manipulating only the set point of temperature, humidity, and on-off time, it would be best to set up the on-off time at 60-30 seconds in time control, the lower limit of air temperature at 30 to $32^{\circ}C$ and the upper limit of relative humidity at 85 to 90%.

• Journal of Wetlands Research
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• v.23 no.4
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• pp.352-363
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• 2021

The purpose of this study was to evaluate the load of nutrients contained in the drainage discharged from the facility horticultural complex and to use them for re-use of fluids and design for introduction of water treatment plants. Representative hydroponic cultivation crops were selected as tomato, paprika, cucumber, and strawberry, and the total number of samples analyzed for water quality was 80. As a result of the analysis, since various fertilizer components such as N, P, K⁺, Na⁺, Mg²⁺, Ca²⁺, Si₄⁺, HCO₃^-, Cl^-, S^2-, Fe, Mn, Cu, Zn, Mo and B are contained at very high concentrations in the drainage, the need for water treatment was confirmed. Through statistical analysis, it was analyzed that the drainage concentration of strawberries was lower than that of tomatoes, paprika, and cucumbers. In the case of tomatoes, these essential ion concentrations are the highest, so it was confirmed that they are subject to valuable resources in terms of reuse of fertilizers. The load of N and P of the drainage discharged from the facility horticultural complex 1m² was analyzed. For N, the daily processing capacity of 4.0 kg of tomatoes, 3.3 kg of paprika, 3.0 kg of cucumbers, and 1.5 kg of strawberries was calculated based on 1 ha. It was suggested that the P concentration needs a scale and capacity that can handle 0.5 kg of tomatoes, 0.6 kg of paprika, 0.4 kg of cucumber, and 0.2 kg of strawberries per day. Through this study, the amount of nitrogen and phosphorus contained in the drainage discharged from the greenhouse of each crop was evaluated to analyze the economy. In addition, it was expected to be used as basic data that can be used to calculate the treatment capacity to be reflected when introducing water treatment facilities in facility horticultural complexes for sustainable agriculture.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.504-512
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• 2022

To examine the distribution of internal solar radiation within various locations in multi-span greenhouses, the solar radiation, light transmittance, and accumulated radiation at the central and lateral sections were analyzed by dividing 8:30 to 12:30 in the morning and 12:35 to 16:30 in the afternoon. The growth and yield of tomatoes within these sections were also compared. In the morning, the solar radiation of the central section and the side section was 275.2 W·m^-2 and 314.9 W·m^-2, while in the afternoon, it was 314.9 W·m^-2 and 313.9 W·m^-2, respectively. The light transmittance and accumulated radiation were also low, confirming the low distribution of solar radiation in the central (connecting) section of the multi-span greenhouses. The growth survey revealed no significant difference. The final yield of tomatoes per plant was 4,828 g in the central section and 4,851 g in the lateral section, but there was no significant difference in the central section compared to the lateral section by 0.5%. However, the amount of solar radiation as per time in the central section is higher than the light compensation point, 60 W·m^-2, and slightly lower than the light saturation point of tomatoes, i.e., 281 W·m^-2. The results of this study can help in greenhouse design based on the insolation environment.