• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.55-60
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• 2001

The efficacy of petroleum spray oil (PSO; D-C Tron $Plus^{(R)}$) against spirea aphid (Aphis citricola) and two scales (lcerya purchasi and Planococcus cryptus) on citrus was tested in Jeju, Korea. The control value of 0.33% PSO against spirea aphid was over 90% at 3 and 6 days after treatment (DAT), and then decreased to about 80% at 9 and 14 DAT. Spraying of PSO (0.33, 0.66, 1%) against cottony-cushion scale showed a much lower control value (less than 50%) during the investigation period compared to that of the conventional pesticide (Methion). When used against tile scale, Planococcus cryptus, the control value of 1% PSO was 95%, but that of 0.33% and 0.66% PSO only ranged from 50 to 80%, lower than the conventional pesticide. The results of this study, as with a previous study, suggest that spraying of 0.33% and 0.5% PSO not only controls the spirea aphid, but also reduces the density of two scales (lcerya purchasi and Planococcus cryptus) on citrus tree in Jeju, without phytotoxic damage.

• The Korean Journal of Pesticide Science
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• v.4 no.4
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• pp.87-92
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• 2000

Recently, a new developed petroleiun spray oil(PSO; D-C Tron $Plus^{(R)}$) has been used to control key pests in integrated pest management (IPM) system of citrus orchards in Australia. The efficacy and phytotoxicity of the PSO against the citrus red mite (Panonychus citri) were compared with conventional pesticides (e.g.Tebufenpyrad, Bifenazate and Sun spray oil) in field condition in Jeju. And under PSO mixing spray with some fungicides, the occurrence of phytotoxic symptoms on citrus leaf was investigated. All concentrations of PSO spraying (0.25%, 0.33%, 0.5% and 1.0%) were significantly suppressed the citrus red mite to similar levels of other conventional pesticides. And the spraying of PSO levels ${\geq}0.5%$ was induced not only occurrence of some oil-sucked symptoms on leaf, but also increase of the dropping leaf and fruit rates. As results from mixing PSO spraying test with other fungicides, little burning on new flush shoot was founded only in PSO 1% plus Fluazinam treatment. From the results of this study, with the consideration of pesticidal efficacy and phytotoxicity, 0.25% and 0.33% PSO spraying level will be recommended for the control of citrus red mite during summer season in Jeju.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.529-537
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• 2022

The susceptibilities of five insecticides to the larvae of Spoladea recurvalis, a major pest of spinach, were evaluated. Lufenuron EC, chromafenozide EC, chlorantraniliprole WP, tebufenozide WP, and pyridalyl EW showed 90% or more insecticidal activity at dilution concentrations of 2 (12.5 ppm), 4 (12.5 ppm), 8 (2.5 ppm), 4 (20.0 ppm), and 8 (12.5 ppm), respectively. At their recommended concentrations, Chromafenozide EC, chlorantraniliprole WP, tebufenozide WP, and pyridalyl EW showed very high insecticidal activity of 98.3%, 100%, 95.0%, and 100%, respectively, after 72 h on S. recurvalis larvae exposed after 7 days of treatment. Field tests at two spinach greenhouses in Hwaseong and Yeoncheon showed a high control effect of over 90% after 7 days of treatment in both areas. In addition, the insecticides can be used as exclusive agents for S. recurvalis that occurs in spinach, as there is no phytotoxicity even at double doses.

• Korean Journal of Weed Science
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• v.2 no.1
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• pp.57-62
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• 1982

This study was conducted to evaluate the important weed occurring in orchard and to establish on effective control method using combination of non-selective foliar applied herbicide followed by soil treated herbicide. In terms of quantity, Calysregia hederacea, Artemisia princeps, Ixeris chinensis, Cephalonopios segetum, Capsella bursa-pastoris, Setaria viridis, Chenopodium album, Trifolium repens, Digitarta sanguinalis in order were observed to be the most important weeds in May, In July the most dominant weeds were D. sanguinalis, Setaria viridis, Amaranthus lividus, Portulaca oleracea, Polygonum hydropiper, Acalypha australis, Artemlsia prtnceps, Miscanthus sinensis in order, showing D. sanguinalis to be the dominant species. D. sanguinalis was one single dominant species till autumn, followed by A. lividus, P. oleracea, A. australis. Simpson's index, 0.159 obtained in May just before herbicide application increased to 0.253 in July and again decreased to 0.233 in Sept. in the oxyfluorfen treated plot, meaning that no specific weed species were dominant, while in the untreated plot, D. saguinalis was relatively single dominant species, showing Simpson's index, 0.540 and this trend was mainained till autumn. The most effective herbicide to control D. sanguinalis and other annuals was oxyfluorfen at 0.47kg a.i./ha. when applied at preemergence treatment, showing more than 80% control of them for 65 days. The results suggest that paraquat at 32/ha (prod.) as the foliar application followed by oxyfluorfen 0.47kg a.i./ha applied as the preemergence at one week after paraquat treatment can maintain the clean orchard more than 65 days, showing one of the promising and applicable control system in orchard.

• Korean Journal of Weed Science
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• v.11 no.1
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• pp.50-59
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• 1991

Residual period and carry-over effect of some herbicides were determined using a bioassay method in six summer crops(potato, carrot, corn, water melon, soybean, and sesame). The effects were measured at regular time intervals after applying different rates of the herbicides. There were no great differences in residual period and carry-over injury between the soils and kinds of crops used. However, the residual period varied with the herbicides studied and the carry-over injury was dependent upon season and rate of the herbicide application, sampling depth of soil, and kind and seeding date of the test plant. When the residual herbicides were applied, the carry-over injury could be minimized by selecting tolernet crops, delaying seeding of the crops after application of the herbicides, and regulating the cultivation depth. Herbicides which showed no residual effect by the end of the cropping period(100-120 days for summer crops) and no carry-over effect were alachlor, trifluralin, ethalfluralin, metribuzin, and prometryn. When pendimethalin, metolachlor, linuron, methabenzthiazuron, and simazine were applied at the recommended rate or less, there was no carry -over injury at harvesting time. With doubling the recommended rate, however, the carry-over effect was found in sensitive crops. Napropamide applied at the rate of 300 g a.i./10 a brought about carry-over injury for Italian ryegrass and barley at 140 days in summer crops, whereas the injury was not found in Cruciferae (radish, Chinese cabbage). Nitralin applied at the rate of 150-300 g a.i./10a caused the carry-over injury for Italian ryegrass and barley at 140 days in summer crops. However, there was no injury for Cruciferae.

• Korean Journal of Weed Science
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• v.11 no.1
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• pp.32-49
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• 1991

Residual period and carry-over effect of some herbicides were determined using a bioassay method in five winter crops (chinese cabbage, radish, spinach, onion and garlic). The effects were measured at regular time intervals after applling different rates of the herbicides. There were no great differences in residual period and carry-over injury between the soils and kinds of crops used. However, the residual period varied with the herbicides studied and the carry-over injury was rate of the herbicide application, sampling depth of soil, and kind and seeding date of the test plant. When the residual herbicides were applied, the carry-over injury could be minimized by selecting tolerant crops, delaying seeding of the crops after application of the herbicides, and regulating the cultivation depth. Herbicides which showed no residual effect by the end of the cropping period (200-240 days for winter crops) and no carry-over effect were alachlor, trifluralin, ethalfluralin and prometryn. When pendimethalin, metolachlor, linuron and methabenthiazuron were applied at the recommended rate or less, there was no carry-over injury at harvesting time. With doubling the recommended rate, however, the carry-over effect was found in sensitive crops. Napropamide applied in winter crops at rate of 150-300g a.i./10a brought about carry-over injury for such Gramineae as Italian ryegrass, direct-seeded rice and barley, whereas the injury was not found in lowland-transplanted rice, Cruciferae, Cucurbitaceae and Solanaceae. Long residual herbicide nitralin applied at the rate of 75g a.i./10a caused the carry-over injury for Italian ryegrass, direct-seeded rice, baley and lowland-transplanted rice at 275 days in winter crops. In addition, a slight injury occurred in sesame, perilla and spinach, However, there was no injury for Cruciferae, Cucurbitaceae and Solanaceae.