• Korean journal of applied entomology
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• v.11 no.1
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• pp.37-40
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• 1972

Experiments were carried out to control white-tip nematode, Aphelenchoides besseyi Christie, during the period just before transplanting. The experimental results were summarized as fellows: 1: From a 12-hr to a 24-hr sled-soaking application into 500 times dilutions of Malathion $80\%$ Ec, Sumithion $50\%$ EC and Lebaycid $50\%$ EC were highly effective than other emulsifierble concentrations of chemicals. 2) The water surface application of PSP-204 $5\%$ G, Diazinon $3\%$ G, Nemagon $20\%$ G and Terracurr-P $5\%$ G were effective. 3: Root·dipping application of Sumithion $50\%$ Ec, Lebaycid $50\%$ Ec and Nemagon $80\%$ Ec were more effective chemicals than others.

• Research in Plant Disease
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• v.10 no.2
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• pp.142-144
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• 2004

Effect of potassium phosphonate on control of potato basal stem rot caused by Pythium myriotylum in hydroponics system was evaluated at spring and fall cultivation in Jeju island in 2001. Potassium phosphonate 200 ppm treatment, which was directly supplemented into the nutrient solution, showed 90.5%, and 100 ppm treatment showed 50.5% control value in spring cultivation. Fall cultivation, potassium phosphonate 200 ppm treatment showed 100%, and 100 ppm treatment showed 69.9% control value. Potassium phosphonate 200 ppm treatment, basal stem rot of potato started to develop 10 days ofter inoculation into the hydroponics system showed 8.0% in infection rate. Potassium phosphonate 100 ppm treatment, after 5 days showed 10.0%, and after 10 days showed 20.0% infection rate, but the non-treated was after 5 days showed 56.7%, and after 10 days showed 96.9% infection rate.

• Korean Journal of Organic Agriculture
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• v.22 no.2
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• pp.347-357
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• 2014

This study was conducted to evaluate the control effect of sodium dichloroisocyanurate (NaDCC) for Venturia nashicola on Niitaka pear during flowering period. As a nontoxic disinfectant, sodium dichloroisocyanurate is widely used in the field of hygiene and disease prevention, medical treatment, aquiculture as well as plant protection. NaDCC was sprayed on the pear tree inoculated with conidia ($4.5{\times}10^5spores/mL$) of Venturia nashicola and as a result the incidence of pear scab was 23.8% in 750mg/L and 26.2% in 1,000mg/L compare to the 51.6% incidence in untreated tree. No damage in the pollen of pear flower was detected with NaDCC treatments in the full bloom period for six pear cultivar including Wonwhang. A NaDCC single treatment in the early bloom of Niitaka pear showed more than 98% of fertilization rate. Furthermore, there was no incidence of Venturia nashicola on Nitaka pear trees treated with NaDCC 4 times during their growth period.

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.308-312
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• 2011

A new paddy field herbicide, metazosulfuron granule is an herbicide for controlling annual and perennial weeds occurring in machinery transplanting paddy field. It is recommended to apply $30kg\;ha^{-1}$ 15 days after transplanting. As a result of preliminary tests, it could control seven annual species such as Echinochloa crus-galli, Bidens tripartita, Ludwigia prostrata, Monochoria vaginalis var. plantaginea, etc. and four perennial species including Cyperus serotinus, Sagittaria trifolia, Eleocharis kuroguwai, and Scirpus juncoides. Monochoria vaginalis var. plantaginea, S. trifolia and S. juncoides resistant to sulfonylurea- herbicides were also controlled. Because application timing of the herbicide is wide, it is very efficient to control the spraying timing by users. Phytotoxicity of rice cultivars was not observed, and the impact on the environment is very limited.

• Korean journal of applied entomology
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• v.22 no.1 s.54
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• pp.21-25
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• 1983

To develop forecasting methods of rice sheath blight caused by Rhizoctonia solani, two rice cultivars Jinheung (Japonica type) and Yushin (Tongil type) were used from 1976 to 1981. Severity of rice sheath blight disease at maturing stage was estimated by top lesion height, percentage of top lesion height vs. plant height in July and lesion index on September 11. The relationship between top lesion height on July 11 and degree of damage at maturing stage for a cultivar Yushin was represented by the equation of Y=4.64x-13.2, and $r=.840^{**}$, where Y is degree of damage by shea4h blight at maturing stage and x is top lesion height on July 11. Considering the percentage of infected hills/stems was rapidly increased from July 11 to August 1, the most effective period and time for fungicide spray were considered July 15 and July 25 or July 25 and August 5.

• Korean journal of applied entomology
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• v.37 no.2
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• pp.117-121
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• 1998

This experiment was conducted to investigate host preference, occurrence and intraplant distribution of Trialeurodes vaporariorum (Westwood) and Encarsia formosa (Gahan) in greenhouse. T vaporariorum preferred cucumber over tomamto. 7: vaporariorum adults distributed at upper part of cucumber plant. Nymphs also distributed at upper part in early growing stage of cucumber but became to distribute lower part after 40 days. E. formosa adults were found mainly at mid-upper part of plant but there was no significant difference in statistics all analysis among each parts and also mummy distributed mid-low part. E. formosa were released when five ir: vaporariorum were caught by yellow sticky trap per week in glasshouse. The treatment of one tag (50 mummies) of E. formosa per five plants controlled successfully the 7: vaporariorum population after 40 days.

• The Korean Journal of Pesticide Science
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• v.5 no.4
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• pp.45-49
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• 2001

As a series of studies to develop pest management system for sweet persimmon production matched with the quarantine criterion of sweet persimmon-imported county, a survey was conducted by questionnaire on pest management practice and scheme of increasing income in sweet persimmon farms in Korea. Above 80% of sweet persimmon farmers was over fifties in age. The greatest limiting factor for sweet persimmon production was thought to be disease by the farmers. Percentage of farmers who answered that the most important pest is anthracnose cause by Gloeosporium kaki, and stink bugs was 64.6% and 73.5%, respectively. In particular, the farmers did not consider Dichocrocis punctiferalis, a main targer insect for quarantine in USA, as serious problem. Obtaining information on pest management practice or decision-making on both selection of pesticide and time of pesticide application depended highly on their own experience with the highest proportion. Eight to nine times of pesticide applications a year was highest among farms with 56.6%. More than 80% of farmers recorded the diary of pesticide application. farmers considered increasing cost for pest management as the greatest problem with 35.4% in proportion, and 34.5% of farmers pointed out that increase in export is essential for increasing farm income with highest proportion.

• The Korean Journal of Pesticide Science
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• v.3 no.3
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• pp.45-53
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• 1999

Red sorrel (Rumex acetosella L.) is a troublesome perennial weed in the alpine grasslands of Kangwon Province of Korea. A number of soil- and foliar-applied herbicides were evaluated for their efficacy of red sorrel control. In greenhouse experiments, no soil-applied herbicides, such as pendimethalin, simazine, alachlor, metolachlor, ethalfluralin controlled red sorrel, however, foliar-applied herbicides, such as glufosinate, paraquat, glyphosate, glyphosate + 2,4-D, dicamba, mecoprop, 2,4-D, bentazone controlled more than 60% of red sorrel 2 weeks after treatments. When dicamba and 2,4-D were applied to red sorrel in different growth stages, the auxin-type of herbicides cold control red sorrel regardless of growth stage. This result implies that the auxin-type herbicides can be applied between early May (early growth stage) and mid lune (before fruit maturation) at Kangwon alpine grasslands. In a field experiment, glufosinate at 1.0 kg a.i, $ha^{-1}$, glyphosate at 3.28 kg a.i. $ha^{-1}$, dicamba at 0.96 kg a.i. $ha^{-1}$, and mecoprop at 150 kg a.i. $ha^{-1}$ controlled more than 80% of red sorrel 4 weeks for treatment, suggesting such herbicides could be applied for red sorrel control at Kangwon alpine grasslands.

• Korean journal of applied entomology
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• v.43 no.3 s.136
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• pp.249-255
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• 2004

This study was conducted to determine Seasonal Occurrence, soybean damage and control efficacy of bean bug, Riptortus clavatus Thunberg at soybean field in Honam province. Occurrence of R. clavatus varied at seeding times with annual difference. The peak occurrence of R. clavatus was appeared at late of August for late May seeding and middle of September for middle June seeding. There was difference in the peak occurrence of R. clavatus due to different growing stages affected by different weather conditions though soybean was seeded at same time. If the rate of soybean seed damage area by R. clavatus sucking increases, the germinating rate was greatly decreased. If the rate of soybean seed damage area is above 50 percent, in particular, the germinating rate was very low with 2 percent. Control efficacy against R. clavatus was the highest with $91\%$ at 3 times treatment of insecticide at $R_4$ (full pod stage) + $R_5$ (Beginning seed stage) +$R_6$ (full seed stage) of soybean growing stages in field.

• Korean journal of applied entomology
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• v.54 no.1
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• pp.1-6
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• 2015

This study was conducted to estimate the economic injury level (EIL) to leaf broccoli (leaf vegetable) by the diamondback moth (Plutella xylostella L.) in 2007 and obtain basic data for pest management. To investigate the relationship between initial density of diamondback moth larvae and broccoli leaf yield, experimental plots with five treatments (0, 0.5, 1.0, 1.5 and 2.0 larvae per plant) as initial density were established. We inoculated larvae on cheesecloth covering to survey changes in larval density. When grown for consumption, leaves of broccoli are harvested in periods. High levels of larvae were associated with significant reductions in leaf yield. There were 0%, 15%, 35%, 42%, 44% yield reductions due to a density of 0, 0.5, 1.0, 1.5, 2.0 diamond back moth larvae per plant, respectively, 25 days after larva inoculation. The regression equation used to predict leaf yield based on the number of initial larvae per plant was y = 1636-394x($R^2=0.79^{***}$>). EIL of the diamondback moth on leaf broccoli was 2~3 larvae per 10 plants for a damage level of 5%. The economic threshold was 1~2 larvae per 10 plants. Thus, diamondback moth management should be initiated when 1~2 larvae appear on 10 plants.