• Korean Journal of Soil Science and Fertilizer
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• v.25 no.3
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• pp.242-248
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• 1992

This study was carried out to investigate the effects of root-zone temperature in hydroponics on the plant growth and nutrient uptake of lettuce(Lactuca sativa L), tomato (Lycopersicon esculentum Mill), and cucumber (Cucumis sativus L). Respiration rate in roots increased with increase in root-zone temperature. At $10^{\circ}C$ of root-zone temperature, respiration rate in lettuce root was higher than those in tomato and cucumber. Increasing rate of root respiration in tomato with increase in root-zone temperature was greater than those in lettuce and cucumber. The lowest dry weight and leaf area of the crops studied were obtained at $10^{\circ}C$ of root-zone temperature, but they were not different between 20 and $30^{\circ}C$. Increase in root-zone temperature generally resulted in increase in T/R ratio and net assimilation rate. At the low root-zone temperature, root growth and leaf area of tomato and cucumber were severely affected. Relative growth rates of lettuce and cucumber were also greatly reduced by the low root-zone temperature. Contents of N, P, K, Ca, and Mg in the crops increased as root-zone temperature increased from 10 to $20^{\circ}C$, whereas only Ca content in tomato and cucumber increased with increase in root-zone temperature to $30^{\circ}C$. Remarkably low contents of P and Mg in the crops were found at the low root-zone temperature. Inhibition of plant growth and nutrient uptake due to low root-zone temperature was much greater in cucumber than in lettuce and tomato.

• Korean Journal of Environmental Agriculture
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• v.29 no.4
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• pp.328-335
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• 2010

This study was conducted to determine effects of soil pH and form of nitrogen fertilizers on tomato growth and chemical properties of greenhouse soil using ferigation system. Tomato (Lycopersicon esculentum Mill. cv. Superdoterang) were grown for three months in 18 L pots filled with two soil (pH 6.8 and pH 8.7). 4 different nitrogen fertilizers (urea, ammonium nitrate, ammonium sulfate, and potassium nitrate) were fertigated with different concentrations of 0, 10, 50, and 100 mg N/L during tomato cultivation. Soil pH 8.7 decreased yield and chlorophyll fluorescence compared with soil pH 6.8. Yield at soil pH 8.7 increased by ammonium nitrate and ammonium sulfate fertigation. Soil pH 6.8 induced increment of yield by nitrogen concentration than form of nitrogen fertilizers. Soil pH after cultivation of tomato decreased by application of ammonium nitrate and ammonium sulfate. Soil EC by 100 mg N/L application of ammonium sulfate was twice as much as other fertilizers. Form of nitrogen fertilizer had less effect on concentration of soil $NH_4^+$-N and $NO_3^-$-N in soil but the concentrations slightly reduced at pH 8.7. These results indicate that application of urea and ammonium nitrate for a nitrogen source of fertigation has little affects on soil chemical properties before and after tomato cultivation.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.19 no.1
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• pp.17-27
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• 2013

The effects of chlorine dioxide gas ($ClO_2$) treatments between high-concentration-short-time and low-concentration-long-time on maintaining the quality of cherry tomatoes (Lycopersicon esculentum Mill. cv 'unicorn') were investigated. Tomatoes were treated with 5 ppm for 10 min and 10 ppm for 3 min as high-concentration-short-time $ClO_2$ gas treatment conditions and 1 ppm for once a day interval in terms of low-concentration-long-time $ClO_2$ gas treatment condition, respectively. After $ClO_2$ gas treatments, tomatoes were storage at 5 and $23^{\circ}C$ for 7 days. Weight loss, changes in tomato color, firmness, soluble solids content, pH, growth of total microorganism, and decay rate were evaluated. On day 7, tomatoes treated with chlorine dioxide gas showed low values of respiratory rate, total microbial growth, and decay rate compared to those of tomato without chlorine dioxide gas treatment. Additionally, tomatoes treated the chlorine dioxide were kept the values of firmness and soluble solids content during storage. However, chlorine dioxide gas treatment on tomatoes had no direct effect on weight loss, pH, and color. Results showed that both $ClO_2$ concentration and treatment time played the important roles for keeping the quality of tomatoes during storage. Tomatoes with chlorine dioxide gas treatment of low-concentration-long-time had more effective values of firmness, the total microbial growth, and decay rate than those with two chlorine dioxide gas treatments of high-concentration-short-time. Results suggest the potential use of chlorine dioxide gas treatment of low-concentration-long-time as an highly effective method for keeping the freshness of cherry tomato.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.479-487
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• 2018

The purpose of this study is to analyze photochemical activity of nursery seedlings under drought stress, using chlorophyll fluorescence reaction analysis. Young nursery seedlings of tomato (Lycopersicon esculentum Mill.) and cucumber (Cucumis sativa L.), were grown under drought stress for 8 days. Analysis of chlorophyll fluorescence reaction (OJIP) and parameters, were performed to evaluate photochemical fluctuation in nursery seedlings under drought stress. Chlorophyll fluorescence reaction analysis showed maximal recorded fluorescence (P) decreased from the 5 day after treatment in tomato seedlings, while an amount of chlorophyll fluorescence increased at the J-I step. Thus, physiological activity was reduced. In cucumber seedlings, maximal recorded fluorescence (P) and maximal variable fluorescence ($F_V$) lowered from the 4 day after treatment, and chlorophyll fluorescence intensity of J-I step increased. Chlorophyll fluorescence parameter analysis showed electron transfer efficiency of PSII and PSI were significantly inhibited with decreasing $ET2_O/RC$ and $RE1_O/RC$ from the 5 day after treatment, in tomato seedlings and from the 4 day after treatment, in cucumber seedlings. $ET2_O/RC$ and $PI_{ABS}$ significantly changed. In conclusion, 6 indices such as $F_V/F_M$, $DI_O/RC$, $ET2_O/RC$, $RE1_O/RC$, $PI_{ABS}$ and $PI_{TOTAL}ABS$ were selected for determining drought stress in nursery seedlings. Drought stress factor index (DFI) was used to evaluate whether the crop was healthy or not, under drought stress. Cucumber seedlings were less resistant to drought stress than tomato seedlings, in the process of drought stress.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.254-259
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• 1998

This study was focused on finding out the potential problems associated with organic farming system. The effect of composted animal manures subsequent inoculation of microbes on growth and yield of tomatoes (Lycopersicon esculentum Mill. 'Minicarol') were examined to develop a proper organic farming practice. Plant heights were greater in composted manure treatment than in conventional practice, whereas widths of leaves were higher in conventional field. Chlorophyll contents between various amount of composted manure application were gradually decreased and showed no significant differences after 45 days of planting. The yield in the treatment applied 12 ton of composted animal manure per 10a as pre-planting fertilizer and following microbial inoculation were only 50-60% compared to that of conventional farming. However, yield increased up to 80% when additional composts were applied to the treatment received 6 ton of composted animal manure per 10a in the middle of cultivation. Microbial inoculation followed by composted manure application induced rapid decrease of nitrogen content in soil. However, the density of microorganisms was significantly increased. Tomatoes produced through organic farming were clear in color, Further, soluble solid and acid content were increased. The highest level of acid and solids were observed in the treatment applied 12 ton of digested swine manure per 10a. Although nitrogen content including ammonium and nitrate rapidly increased after application of composts, these were significantly reduced approximately 4-5 weeks after planting. The level of phosphorus, potassium, magnesium and calcium showed gradual decrease compared to nitrogen.

• Journal of Bio-Environment Control
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• v.12 no.4
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• pp.221-227
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• 2003

The objective of this research was to determine the effect of seed priming on membrane integrity during poriming and germination. Among the five chemicals, $KNO_3$at 150 mL gave the shortest $T_{50}$ (days required to reach 50% of the final germination percentage). Compared to unprimed, the seeds primed with 150 mL $KNO_3$ at 20$^{\circ}C$ for 4 days had reduced $T_{50}$ values when germinated at 15$^{\circ}C$. These results indicated that seed priming is an effective way for rapid and synchronized germination, especially at low temperature. Changes in conductivity of priming solutions during the 4-days period of priming were highly dependent upon the priming agents. Conductivity of the $KNO_3$ and $K_3PO_4$ solution slowly declined during the first 3 hours ad then increased Amount of amino acids, sugars and proteins exuded from seeds into $KNO_3$ solution were less than those into distilled water and $K_3PO_4$. All the results suggested that the $KNO_3$ priming play a positive role in regulating the permeability of cell membranes.

• 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.

• Korean Journal of Environmental Agriculture
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• v.11 no.1
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• pp.50-58
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• 1992

Studies were conducted to determine the combined effect of uniconazole [(E) -1-(4-chlorophenyl)-4, 4-demethyl 2-(1,2,4 triazol-1-yl)-1-penten-3-ol] and silver thiosulfate $[Ag {(S_2O_3)}^3\;_2-]$ (STS) on reduction of ozone injury in tomato plants(Lycopersicon esculentum Mill. 'Pink Glory'). Plants were given a 50ml soil drench of uniconazole at concentrations of 0, 0.001, 0.01 and 0.1 mg/pot at the stage of emerging 4th leaf. Two days prior to ozone fumigation, STS solution contained 0.05% Tween-20 was also sprayed at concentrations of 0, 0.3 and 0.6 mM. Uniconazole at 0.01 mg/pot and STS at 0.6 mM were effective in providing protection against ozone exposure(20h at 0.2ppm) without severe retardation of plant height and chemical phytotoxicity, respectively. Combined treatment with uniconazole, STS significantly reduced ozone injury at the lower concentration than a single treatment with uniconazole or STS. Uniconazole treatment reduced plant height, stem elongation and transpiration rate on a whole plant level and increased chlorophyll concentration. STS did not give any effect on plant growth and chlorophyll content but increased transpiration rate in non-ozone-fumigated plants. Ethylene production in the leaves of ozone-fumigated plants was decreased by uniconazole and STS pretreatment, but there was no protective effect on epinasty of leaves in uniconazole-treated plants. STS increased ethylene production in non-ozone-fumigated plants, but it significantly reduced the degree of epinasty and defoliation of cotyledons when plants were exposed to ozone. Uniconazole slightly increased superoxide dismutase and peroxidase activities. But STS showed little or no effects on such free radical scavengers. Day of flowering after seeding was shortened and percentages of fruit set were increased by uniconazole treatment. STS was highly effective on protecting reduction of fruit set resulting from ozone fumigation. These results suggest that combined use of uniconazole and STS should provide miximum protection against ozone injury without growth retardation resulting in yield loss.

• Korean Journal of Weed Science
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• v.4 no.1
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• pp.69-78
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• 1984

This study was conducted to select herbicides effective for upland crops and to investigate the cause of crop injury in peanut cultivated with mulching. Crop such as radish (Raphanus acanthiformis Moor.), Chinese cabbage (Brassica raps L.), soybean (Glycine max Merr.), Peanut (Archis hypogaea L.), and marsh mallow (Malva olitoria Nakai) were tolerant to napropamide [2-(${\alpha}$-naphthoxy)-N, N-diethylpropionamide], alachlor [2-chloro-2', 6'-diethyl-N-(methoxymethyl) acetanilide], trifluralin (${\alpha},{\alpha},{\alpha}$-trifluoro-2, 6-dinitro-N, N-dipropylp-toluidine) and nitrofen (2,4-dichlorophenyl-p-nitrophenylether). Napropamide, diphenamide (N, N-dimethyl-2, 2-diphenylacetamide) and alachlor were safe for red pepper (Capsicum annuum L.), eggplant (Solanum melongena L. and tomato (Lycopersicon esculentum Mill.), while trifluralin, nitrofen and chlonitrofen (2,4,6-trichlorophenyl-4-nitrophenyl ether) could be used for water melon (Citrullus battich Forsk.), carrot (Daucus carota L.) and lettuce (Lactuca scariola L.) without crop injury. Out of nine major weed species studied, Capsella bursa-pastoris Medicus was the most resistant species to the herbicides tested. Napropamide and alachlor could not control P. hydropiper, while P. oleracea and C. album were tolerant to diphenamide :and alachlor, respectively. Urea herbicides such as methabenzthiazuron [3-(2-benzothiazolyl)-1,3-dimethylurea], linuron [3-(3, 4-dichlorophenyl~l-methoxy-i-methyl urea], and isoproturon [3-(4-isopropylphenyl) -1, 1-dimethylurea]gave a great injury to the crops studied. The weeding effect was greater for broadleaf weeds than for grasses. Isoproturon and linuron provided good selectivity for marsh mallow and carrot, respectively. In peanut, the crop injury caused by Four herbicides studied was greater when cultivated with mulching than when cultivated without mulching. With dinitroaniline herbicides the crop injury decreased as the gaseous herbicide was removed out of mulching. Alachlor gave little phytotoxicity to peanut grown under mulching condition and nitralin [4-(methylsuphonyl)-2, 6-dinitro-N, N-dipropylaniline] showed less toxicity to the peanut than pendimenthalin (3,4-dimethyl-2, 6-dinitro-N-1-ethyl propylaniline) and trifluralin.