• Korean Journal of Weed Science
• /
• v.17 no.4
• /
• pp.390-399
• /
• 1997

This experiment was conducted to introduce PAT (phosphinothricin acetyltransferase, non-selective herbicide bialaphos resistant gene) gene into potato (Solanum tuberosum. cv. Desiree). Optimal shoot regeneration from leaf discs and stem segments was obtained in MS medium supplemented with 0.1 mg/L IBA and 0.5 mg/L BA, and the frequency of shoot regeneration was 54% in left discs and 46% in stem segments. In this condition, leaf discs and stem segments of potato were co-cultivated with A. tumefaciens MP90 which contained binary vector with GUS: :NPTII gene and PAT gene. Transgenic shoots were regenerated from leaf and stem-derived calli on selection medium with 100mg/L kanamycin. The 100${\mu}M$ acetosyringone treatment during the co-cultivation highly enhanced(4 times than the control) the shoot regeneration on selection medium. When the putative transgenic plants were transferred to medium with 10mg/L basta, all of them were survived. After PCR. GUS test, and Southern blot analysis of the survived plant, we confirmed that the gene was stably integrated into the potato genome and expressed. After the transgenic plants were transplanted in soil, and the transgenic plants were sprayed with the herbicide basta (300ml/10a), the transgenic plants remained green but control plants were died.

• The Korean Journal of Pesticide Science
• /
• v.18 no.3
• /
• pp.191-195
• /
• 2014

Occurrence of soybean pod gall midge (SPGM), Asphondylia yushimai, and soybean pod damage caused by SPGM, and its control efficacy treated with ethofenprox 20EC were first observed at Miryang from 2006 to 2008 in Korea. The typical damage symptoms in soybean pod caused by SPGM were brownish coloration and malformation. By beating method occurrence of SPGM was observed from beginning bloom of soybean and its collected population increased with season until middle September. Soybean pod damage caused by SPGM was heaviest at seeding date of 10th May, followed by 11th June and 26th May. Control efficacy against SPGM sprayed with one time application of ethofenprox 20EC at different spray time in soybean reproductive stage was highest with 92.9% at R2.5, followed by 87.9% at R2 and 83.6% at R3, and was low from about 19 to 66% at other spray time. Accordingly, the most effective spray time of insecticide for control of SPGM in soybean field was found to be R2.5 which is between R2 and R3.

• The Korean Journal of Pesticide Science
• /
• v.18 no.3
• /
• pp.148-155
• /
• 2014

The transfer pattern of chlorpyrifos present in soil to cucumber plants were assessed and reported with plant growth, concentration dependency, and duration. Cucumber seedlings cultivated in a growth chamber for 30 days and a greenhouse for 120 days. Weight and length of cucumbers cultivated in the chamber increased with the increasing time, while the uptake of chlorpyrifos by cucumber increased a period from 0 to 15 days and decreased after 15 days. Uptake rates of chlorpyrifos into a cucumber plant were 1.0~1.3% to initial amounts treated with 20 and 40 mg/kg to soil. Most chlorpyrifos residues were detected in root, followed by stem and leaf. Results of the greenhouse test showed that chlorpyrifos amounts in cucumber fruits were present less than LOQ (0.02 mg/kg), and chlorpyrifos was mainly found in the root of the cucumber plant. Chlorpyrifos absorbed in a cucumber under greenhouse condition was smaller than that in chamber condition as 0.03~0.04%. Degradation patterns of chlorpyrifos in soils were similar during indoor and outdoor tests with half-lives of 25.8~73.0 days. These results may be useful for establishing the management strategy of residual pesticides in soil environment.

• The Korean Journal of Pesticide Science
• /
• v.7 no.3
• /
• pp.223-227
• /
• 2003

Survey on plant diseases occurring on cucumber cultivated in plastic film house of experimental farm in Suwon was conducted. Through the survey, occurrence of damping-off, downey mildew, powdery mildew and Fusarium wilt was observed. Especially downey mildew caused by Pseudoperonospora cubensis was the most severe foliar disease of cucumber. To control the disease effectively, effects of installation of ventilation fan and optimal spray timing of a chemical, dimethomorph+copper oxychloride WP, were investigated. Two ventilation fans installed at the front and at the back of plastic film house reduced air relative humidity by about 6.4% and downey mildew incidence by 55.7%. Downey mildew incidence on cucumber from untreated chemicals plot in plastic film house installed with ventilation fan was on a equal level with that from treated chemicals plot with three times application of dimethomorph+copper oxychloride WP in plastic film house without ventilation fan. Meanwhile in order to select optimal chemical application time, dimethomorth+copper oxychloride WP was treated three times at 7 days-interval from three days before the disease occurred, right after the disease occurred, and two days after the disease occurred, respectively. The result showed that dimethomorth+copper oxychloride WP applied to cucumber leaves and stems from three days prior to, right after, two days after occurrence of downey mildew reduced downey mildew incidence by 72.9, 61.8, and 23.7%, respectively. The above results showed that regulation of environmental factors like air relative humidity and preventive application of chemicals should be considered to establish control strategy to downey mildew.

• Korean Journal of Weed Science
• /
• v.12 no.2
• /
• pp.183-187
• /
• 1992

This study was conducted to evaluate the effect of systematic herbicide application and polyethylene(PE) film mulching in direct seeded Angelica gigas Nakai. Freshly-collected-seed showed 86% of emergence rate and required 18 days of emergence duration. Cold treatment of seeds increased emergence rate by more than 90% and shortened 2 days of emergence duration. Paraquat) 1,1'-dimethyl-4,4'-bipyridylium dichloride was the most effective when applied just before emergence of A. gigas and provided 96% of emergence rate and 91% of weeding effect when applied 23 days after seeding. Soil applied herbicides used did not cause any phytotoxicity on emergence with application of 2-fold recommended rate and gave more than 90% of weeding effect. Black PE film mulching gave excellent emergence rate and weeding effect, and shortened emergence duration by 8 days.

• Korean Journal of Weed Science
• /
• v.31 no.1
• /
• pp.71-77
• /
• 2011

This study was conducted to predict the yield loss of red pepper and to determine the economic weed thresholds levels for red pepper cultivation field from competition with the most serious weeds, Echinochlor crus-galli (L.) P. beauv. (barnyard grass) and Chenopodium album L. (goosefoot) in Youngyang of Korea. Crop yield as a function of weed density was predicted by using a rectangular hyperbola, and their economic threshold levels were determined by using the equation developed by Cousens (1987). The red pepper yield loss models of weeds were predicted as y=317.0 kg/ (1+0.1707x), $R^2$=0.895 in E. crus-galli and y=323.2 kg/(1+0.2900x), $R^2$=0.896 in C. album L.. Economic thresholds calculated using Cousens' equation was negatively related with the competitiveness of weed. Economic thresholds of each weed were calculated as 6.5 plant $100m^{-2}$ in E. crus-galli, and 3.7 plant $100m^{-2}$ in C. album L..

• Korean Journal of Weed Science
• /
• v.31 no.4
• /
• pp.340-347
• /
• 2011

This study was conducted to predict the rice yield loss and to determine the economic threshold levels for direct-seeding flooded rice cultivation from competition to the most serious weeds, Sagittaria trifolia L. and Bidens frondosa L. The rice yield loss models of S. trifolia and B. frondosa were predicted as Y = 497.0/(1+0.003760x), $R^2$=0.869 and Y = 486.0/(1+0.007612x), $R^2$ = 0.887, respectively. In comparison of the competitiveness represented by parameter ${\beta}$, it was 0.003760 in S. trifolia and 0.007612 in B. frondosa, respectively. Economic thresholds calculated using Cousens' equation was negatively related with the competitiveness of weed. The economic thresholds of S. trifolia and B. frondosa were 7.6 and 3.9 plants per $m^2$, respectively.

• Weed & Turfgrass Science
• /
• v.1 no.4
• /
• pp.38-43
• /
• 2012

This study was conducted to predict the yield response of red pepper and to determine the economic weed threshold levels for red pepper cultivation field from competition with the most serious weeds, Amaranthus patulus and Digitaria ciliaris in Youngyang of Korea. Crop yield as a function of weed density was predicted by using a rectangular hyperbola, and their economic threshold levels were determined by using the equation developed by Cousens (1987). The red pepper yield loss models of weeds were predicted as y=304.7/(1+0.063x), $R^2$=0.967 in D. ciliaris and y=281.3/(1+0.1723x), $R^2$=0.952 in A. patulus. Economic thresholds calculated using Cousens' equation were negatively related with the competitiveness of weed. Economic thresholds of each weed were calculated as 18.2 plant $100m^{-2}$ in D ciliaris, and 7.2 plant $100m^{-2}$ in A. patulus.

• Korean Journal of Plant Tissue Culture
• /
• v.25 no.4
• /
• pp.283-288
• /
• 1998

The bialaphos is a potent inhibitor of glutamine synthease in higher plants and is used as a non-selective herbicide. We have used the bialaphos resistant gene(Bar) encoding for an acetyltransferase isolated from Streptomyces hygroscopicus SF1293. Callus derived from mature seeds of rice(Oryza sativa L. cv. Dong Jin) were co-cultivated with Agrobacterium tumefaciens EHA101 carring a plasmid pGPTV-HB containing genes for hygromycin resistance (HygR) and Bar. Transgenic plants showing in vitro resistance to 50 mg/L hygromycin and 10 mg/L bialaphos were obtained by using a two-step selection/regeneration procedure. Transformation efficiency of rice was about 30% which was as high as reported in other dicotyledons. Progenies ($\textrm{T}_{1}$ generation) derived from primary transformant of 17 lines were segregated with a 3 resistant : 1 sensitive ratio in medium containing hygromycin and bialaphos. Stable integration of Bar gene into chromosomal DNA was proven by Southern blot analysis of genomic DNA isolated from $\textrm{T}_{2}$ progenies. Transgenic plants ($\textrm{T}_{3}$) grown in the field were resistant to bialaphos (Basta) at a dosage lethal to wild type plants.

• Korean Journal of Organic Agriculture
• /
• v.22 no.3
• /
• pp.445-455
• /
• 2014

The pear sucker (Cacopsylla pyricola) is the most important insect pest in Korea. The hatching rates of overwintered adults laid eggs were observed at 10, 13, 18, and $22^{\circ}C$. The liner model was draw as Y=0.00277X+0.00146(Y=developmental rate, X=temperature) about temperature and developmental rate to eggs. The developmental threshold temperature to eggs was assumed about $-0.83^{\circ}C$. The egg hatching timing over 50% as the accumulated temperature by day maximum temperature $6^{\circ}C$ over from 1st February in 2008, 2009 and 2011 was 429.7, 417.6, and 424.3 degree $^{\circ}C$, respectively, was 3 to 7days before full blooming in pear orchard. On the other hand, the abamectin 1.8EC, lime sulfer, machine oil and 13 kinds of eco-friendly materials were not shown the control effect to the eggs. To mixed stage of pear sucker, the eco-friendly materials over 90% control value were 4 kinds such as a mixture of Azadiractin A+B, Nimbin, Salanin, Meliantriol and Vepol after twice application as 21st May and 5th June in pear growing season, in 2012.