• Journal of Applied Biological Chemistry
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• v.62 no.1
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• pp.11-17
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• 2019

Strawberries are one of the main commodities in Korea and have been exported over 40 million dollar. Because the strawberry cultivation using hydroponics has increased, treatment of pesticide by drenching draw interest recently. However, detailed researches for drenching treatment of pesticide are limited, which results in difficulties in proper pesticide applications in agricultural fields. To activate use of drenching and improve safety in agricultural products, In this study, time-dependent residual characteristic of pesticides were compared with between different applications of pesticides in strawberries. The characteristics of azoxystrobin, prochloraz and thiamethoxam were investigated with drenching treatment at different applications: the time of treatment, concentration etc. at hydroponic cultivation for 40 days. Azoxystrobin and prochloraz were not detected at 14 day after application. Thiamethoxam was detected from 0.02 to 0.85 mg/kg. Crop uptake of pesticides was strongly affected with octanol-water partition coefficient and solubility in water. Residual amount in crops are highly dependent on the concentration of active ingredient of pesticides.

• Journal of Applied Biological Chemistry
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• v.60 no.4
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• pp.313-319
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• 2017

Strawberries are one of the main commodities in Korea and have been exported over 30 million dollar. And the safety has recently become an important issue in the agro-trade, pesticide residue is most important matter of safe agricultural products. As strawberries can be cultivated using elevated production system, so it is possible to use the drenching. When spraying the pesticides, the use of drenching can be lower amount of residual than using foliar treatment. In this study, time sequential residual amount of pesticides were compared between drenching and foliar application in strawberries. Pesticides were treated with the standard and double dosage and samples were collected at 0, 3, 6, 9, 13, 16 and 21 day and analyzed by LC and LC-MS/MS after liquid-liquid extraction and QuEChERS. Two pesticides were detected less than 1 mg/kg in all samples for drenching treatment. Carbendazim residues in drenching treatment were 5 to 25 times lower than foliar application. And azoxystrobin was not detected in strawberries of drenching treatment.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.04b
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• pp.65-66
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• 2001

제주도의 감자재배면적은 전국의 30.6%를 차지하고 있으며 본도 제2의 소득작물로 자리잡고 있는데 최근 국내외적으로 친환경농산물에 대한 관심이 고조됨에 따라 안전농산물에 대한 수요가 늘면서 유기농업자제를 이용한 고품질 안전 농산물을 생산하려는 시도가 늘어가고 있다. 이런 관점에서, 키토산을 \circled1토양처리 (1kg/a), \circled2키토산침지 (0.2%/30분), \circled3토양처 리＋생육기처리 100배 (2회), \circled4토양처리＋생육기처리 200배 (2회), \circled5생육기처리 100배 (2회), \circled6생육기처리＋200배 (2회), \circled7무처리로 구분하여 시험하였다. 발아율은 대조구에 비해서 종서침지, 토양관주＋생육기 200배처리, 생육기 200배처리한 것이 다소 높은 편이었고, 경장 경수 및 복지수는 시일이 경과할수록 많은 편이고 그 중에서 종서침지가 가장 양호한 편이었다. 그리고 10a당 총수량, 상서수량 및 설서수량(30g이하인 괴경)은 역시 종서침지, 토양관주＋생육기 200배 (2회)처리 및 토양관주＋생육기 100배처리 순서로 상서수량이 많은 편이었다. 처리별 상서수량은 종서침지한 것이 71%, 29%로 가장 많았고 토양관주＋생육기 100배처리한 것이 대조구보다 많은 경향이었다(Table 1).

• FLOWER RESEARCH JOURNAL
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• v.19 no.3
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• pp.127-138
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• 2011

Four different plant growth retardants (PGRs), paclobutrazol, flurprimidol, daminozide, and chlormequat, were applied to potted Saxifraga rosacea 'Kumoma' and 'Kumoma-Gusa' plants for control of the growth and flowering. Paclobutrazol (10, 20, 40, $80mg{\cdot}L^{-1}$), flurprimidol (5, 10, 20, $40mg{\cdot}L^{-1}$), daminozide (500, 1000, 2000, $4000mg{\cdot}L^{-1}$), and chlormequat (50, 100, 200, $400mg{\cdot}L^{-1}$) were applied to the plants by a foliar spray or drenching. In 'Kumoma', application of $40mg{\cdot}L^{-1}$ paclobutrazol by a foliar spray or drenching reduced plant height by 12.5 and 12.6 cm, and flower length by 3.4 and 3.3 cm, respectively. On the other hand, in 'Kumoma-Gusa', drenching of paclobutrazol reduced plant height by 10.7 to 12.6 cm and flower length by 2.0 to 3.9 cm with increasing concentration, but the number of florets almost fell to 20 as compared to 40.5 in the control. 'Kumoma-Gusa' plants drenched with $80mg{\cdot}L^{-1}$ paclobutrazol and sprayed with $40mg{\cdot}L^{-1}$ flurprimidol had the shortest heights of 10.7 and 9.9 cm, and floral length of 2.0 and 1.5 cm, respectively. A flurprimidol drenching at $40mg{\cdot}L^{-1}$ delayed the harvest by 3-13 days as compared to the control and the smallest number of florets, 15.6, was observed in this treatment. In both cultivars, chlormequat and daminozide did not effectively influence the growth and flowering. However, number of florets increased to more than 41 at all concentrations and up to 63, the greatest floret number, with chlormequat drench in 'Kumoma-Gusa'. These results demonstrated that over $40mg{\cdot}L^{-1}$ of paclobutrazol or 5 to $20mg{\cdot}L^{-1}$ of flurprimidol could be used as PGRs to control the growth of floral length and flowering for improving potted plant quality in S. rosacea 'Kumoma' and 'Kumoma-Gusa'.

• Journal of Life Science
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• v.13 no.6
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• pp.889-895
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• 2003

This experiment was carried out to investigate the effect of subirrigation of Dolrido on the growth and development of stem cutting and young roes plant. Plant growth was measured at 20, 40, and 60 days after subirrigation of Dolrido. Plant height, stem diameter, number of leaves, leaf area and root length of cutting rose subirrigation were more affected than those of control. The growth of young seedling was significantly affected by subirrigation of Dolrido. Plant height, number of leaves, stem diameter, leaf area, fresh and dry weight were increased with subirrigation of Dolrido. However, T/R ratio was not affected by subirrigation of Dolrido. Growth of seedlings was promoted after 60 days treatment of Dolrido.

• Korean Journal of Organic Agriculture
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• v.18 no.4
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• pp.541-548
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• 2010

This study was established on which the selenium (Se), known as one of the functional elements in the human body, treatment was the most effective for the Se uptake in the soil and tree. Se treatments included foliar application, soil fertigation, and trunk injection. Se fertigation and control had similar soil $P_2O_5$, K, and Mg concentrations, and calcium and Se concentrations in the soil were greater on the control and Se fertigation, respectively. Leaf characteristics were not different among the treated trees. No differences were observed for the leaf K and Ca concentrations among the treated trees, and foliar Mg was greater on the Se treated trees than the control. Se foliar application and trunk injection had greater Se concentrations in the leaves and fruits than the Se fertigation and control.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.271-276
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• 2012

A mycoparasite, Paraconiothyrium minitans CM2 was selected for biological control of sclerotinia rot of lettuce caused by Sclerotinia sclerotiorum. The experiment was carried out in a lettuce greenhouse in Yangpyeong from March to April.. When lettuce sclerotinia rot showed in the early stage of occurrence, Conidial suspension of the mycoparasite was weekly treated once to three times onto soil surface around lettuce plants. Incidence of sclerotinia rot in the once-application plot of the mycoparasite ($1{\times}10^7$ spores/$m{\ell}$) and in the benomyl(WP)-treated plot was 11.0% and 2.7%, respectively, whereas that of control was 31.0%. Incidence of twice- and three-application plots of the isolate was 7.9% and 12.8%, respectively. For increasing the effect of the mycoparasite, the experiment for the timing of application of P. minitans CM2 was carried out in a lettuce greenhouse in Yangpyeong and Suwon. Control efficacy against lettuce sclerotinia rot in the soil-drenching plots of P. minitans CM2 ($5{\times}10^6$ spores/$m{\ell}$) in the planting was 75.3~84.7%, and control effect by treatment of the isolate at the pot drenching+the soil-drenching plots in the early stage of disease occurrence was 63.8~58.0%. As the results, P. minitans CM2 could be a prospective biofungicide for biological control of sclerotinia rot of lettuce.

• Horticultural Science & Technology
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• v.17 no.5
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• pp.581-583
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• 1999

This experiment was conducted to investigate the effects of uniconazole drench treatment on the growth and flowering of poinsettia and to suggest proper application dosage and time. Plant height, branch length, and leaf area were significantly restricted as the concentration of uniconazole increased. Application doses of 0.05 and 0.10 mg/pot effectively controlled the growth of poinsettia 'V-10 Amy'. Earlier soil drench of uniconazole resulted in more effective reduction in plant height, branch length, and leaf area. In all cases, no noticeable phytotoxicity by plant growth retardants tested was observed.

• Korean Journal of Organic Agriculture
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• v.19 no.1
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• pp.83-92
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• 2011

This study was established to investigate the effects of Ca application on fruit mineral nutrients, quality, and browning of 'Fuyu' sweet persimmon (Diospyros kaki). Ca foliar application at 40ml/20L/tree had a greater fruit Ca concentration than did control, Ca fertigation (40ml/20L/tree), and Ca foliar application (40ml/20L/tree) coupled with IBA fertigation (40ml/20L/tree). Fruit mineral nutrient concentrations for Mg, B, and Mn were similar or lower in the foliar treatment compared to other treatments. Fruit color was not affected. Ca treatment, whether foliar applied or fertigated, was effective in maintaining fruit firmness and in decreasing the browning symptom in fruit after MA storage at $0^{\circ}C$ for 60 and 100 days. Although Ca foliar application + IBA fertigation treatment improved fruit firmness, the positive effect on the browning and decay occurrences in fruit was not shown.

• Horticultural Science & Technology
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• v.17 no.3
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• pp.355-360
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• 1999

This study was carried out to investigate the effect of irrigation frequency, particle size and depth of perlite medium on the growth of Dendranthema grandiflorum (Ramat.) Kitamura 'Shuhouno-chikara' grown on recycling system. In Exp 1, the irrigation frequency (IF) was designed as 3 (IF3), 9 (IF9), and 18 (IF18) times a day. Fine and coarse particle size (PS) of perlite was used as a media, and depth of media (DM) was 15 and 10 cm contained in $34{\times}120{\times}15cm$ styrofoam bed. In Exp 2, the IF was 3 (IF3), 6 (IF6), and 9 (IF9) times a day with the same amount of nutrient solution. Fine and coarse PS were used, and DM was 15 and 7.5 cm. In this study, high IF and fine PS was favorable for plant growth. However, as the IF became frequent, difference of plant growth between fine and coarse PS became smaller. Also, shallow media showed little difference with deep media in plant growth. Thus, decreasing the amount of media was recommended to reduce the production cost.