Repellency of aerosol and cream products containing fennel oil to mosquitoes under laboratory and field conditions

The repellency of fennel (Foeniculum vulgare Miller)-containing products (5% aerosol and 8% cream) against mosquitoes was compared with those of citronella oil, geranium oil and deet, as well as three commercial repellents, Baby Keeper cream containing IR3535, MeiMei cream containing citronella and geranium oils, and Repellan S aerosol containing 19% N,N-diethyl-m-toluamide (deet) under laboratory and field conditions. In a laboratory study with female Aedes aegypti (L), fennel oil exhibited good repellency in a release-in-cage test and repellency in skin and patch tests of the oil was comparable with those of citronella and geranium oils. In paddy field tests with five human volunteers, 5% and 8% fennel oil-containing aerosol and cream produced 84% and 70% repellency, respectively, at 90 min after exposure, whereas Baby Keeper cream and MeiMei cream gave 71% and 57% repellency at 90 min after exposure, respectively, and Repellan S aerosol gave 89% repellency at 210 min. The species and ratio of mosquitoes collected were the genera Culex (44.1%), Anopheles (42.2%), Aedes (7.8%) and Armigeres (5.9%). Fennel oil-containing products could be useful for protection from humans and domestic animals from vector-borne diseases and nuisance caused by mosquitoes.     

Enhanced repellency of binary mixtures of Zanthoxylum piperitum pericarp steam distillate or Zanthoxylum armatum seed oil constituents and Calophyllum inophyllum nut oil and their aerosols to Stomoxys calcitrans

BACKGROUND: The repellency to stable fly, Stomoxys calcitrans (L.), of Zanthoxylum piperitum (L.) DC pericarp steam distillate (ZP‐SD), Zanthoxylum armatum DC seed oil (ZA‐SO) and their constituents alone or in combination with Calophyllum inophyllum L. nut oil (CI‐NO), as well as six aerosol formulations containing ZP‐SD or ZP‐SO and CI‐NO, was compared with that of a synthetic repellent, DEET, using an exposed human hand bioassay. RESULTS: At 0.20 mg cm^?2, ZP‐SD treatments resulted in 91 and 68% repellency following 30 and 60 min exposure respectively, while DEET gave 100 and 84% repellency. ZA‐SO was less effective than ZP‐SD. At 0.2 mg cm^?2, the most active constituents, cuminaldehyde, cuminyl alcohol, limonene and methyl cinnamate, gave 82, 74, 74 and 64% repellency at 30 min respectively, but DEET gave 100 and 87% repellency at 30 and 60 min. An increase in effectiveness and duration of repellency was produced by binary mixtures of ZP‐SD, ZA‐SO or bioactive constituents (each 0.01 mg cm^?2) and CI‐NO (0.99 mg cm^?2). The repellency of aerosols containing 2.5% ZP‐SD or 2.5% ZA‐SO and 2.5% CI‐NO was comparable with that of 5% DEET aerosol. CONCLUSION: Mixtures formulated from ZP‐SD, ZA‐SO or bioactive constituents and CI‐NO could be useful as potential repellents for the control of stable fly populations in light of global efforts to reduce the level of highly toxic synthetic repellents. Copyright © 2010 Society of Chemical Industry     

Toxicity of spray and fumigant products containing cassia oil to Dermatophagoides farinae and Dermatophagoides pteronyssinus (Acari: Pyroglyphidae)

The toxicity of formulations of oil of cassia, Cinnamomum cassia Blume, (20 and 50 g L(-1) sprays and 100% oil-based fumigant) to adult Dermatophagoides farinae Hughes and D. pteronyssinus Trouessart was examined using contact and vapour-phase toxicity bioassays. Results were compared with the lethal activity of three commercial acaricides: benzyl benzoate, dibutyl phthalate and diethyl-m-toluamide (deet). The contact toxicity of cassia oil to both dust mite species was comparable with that of benzyl benzoate but was higher than that of the other two acaricides. Sprays containing 20 and 50 g L(-1) cassia oil were effective against both mite species when applied to fabric, glass, paper, plastic, tin or wood substrates. Applications of the 50 g L(-1) spray to different space volumes and surface areas determined that 50-60 mg of cassia oil was needed to control dust mites in 3.4 m(3) or in 1 m(2). In tests with fumigant devices, toxicity varied according to the thickness of non-woven fabric covering the device, the exposure time, the number of fumigant devices used and the volume of the space sprayed. Fumigant toxicity to adult D. pteronyssinus was more pronounced with devices enclosed in thinner (40 microm) versus thicker (45 or 50 microm) non-woven fabric covers. A single fumigant device with a 40 microm thick non-woven fabric cover resulted in substantial control in a space of 0.05 m(3) but exhibited only moderate to weak control in spaces >or= 0.097 m(3) at 4 days after application. Two fumigant devices gave 88% mortality in a space of 1.73 m(3). Cassia oil applied as sprays or in fumigant devices appears to provide effective protection of humans from house dust mites.     

Acaricidal activities of paeonol and benzoic acid from Paeonia suffruticosa root bark and monoterpenoids against Tyrophagus putrescentiae (Acari: Acaridae)

The acaricidal activities of paeonol (2'-hydroxy-4'-methoxyacetophenone) and benzoic acid identified in the root bark of tree peony, Paeonia suffruticosa Andrews, against copra mite, Tyrophagus putrescentiae (Schrank), adults were examined using direct contact and vapour phase toxicity bioassays and compared with those of cinnamyl acetate, cinnamyl alcohol and 37 monoterpenoids as well as the acaricides benzyl benzoate, dibutyl phthalate and N,N-diethyl-m-toluamide (DEET). Based on LD(50) values in fabric piece contact toxicity bioassays, the acaricidal activities of benzoic acid (4.80 microg cm(-2)) and paeonol (5.29 microg cm(-2)) were comparable to that of benzyl benzoate (4.46 microg cm(-2)) but more pronounced than those of DEET (30.03 microg cm(-2)) and dibutyl phthalate (25.23 microg cm(-2)). In vapour phase toxicity bioassays, paeonol and benzoic acid were much more effective in closed containers than in open ones, indicating that the effects of these compounds were largely due to action in the vapour phase. As judged by 24 h LD(50) values, (1S)-(-)-verbenone (7.42 mg per disc) was the most toxic fumigant, followed by (1S)-(-)-camphor, (S)-(+)-carvone, (R)-(-)-linalool and (+/-)-camphor (10.45-18.18 mg). Potent fumigant toxicity was also observed with paeonol, (2S,5R)-(-)-menthone, (+/-)-citronellal, benzoic acid, (1S,4R)-(-)-alpha-thujone and (R)-(+)-pulegone (25.10-34.63 mg). Neither benzyl benzoate, DEET nor dibutyl phthalate caused fumigant toxicity. Paeonia root bark-derived materials, particularly paeonol and benzoic acid, as well as the monoterpenoids described, merit further study as potential acaricides or as leads for the control of T. putrescentiae.     

A standardised in vivo and in vitro test method for evaluating tick repellents

The threat of transmission of Lyme borelliosis and tick-borne encephalitis by ixodid ticks has resulted in an increasing number of tick repellents coming onto the market. To allow proper evaluation of the efficacy of different types of compounds and their formulations, there is a need for standardised methods for testing ticks repellents. Ticks show a marked negative geotactic response following contact with a potential host, i.e., they climb up in order to locate attachment and feeding sites, whereas exposing ticks to repellents induces positive geotaxis, i.e., ticks walk downwards or drop off the treated host or substrate. We describe here complementary tests that employ these geotactic responses to evaluate repellents: one in vitro on a warm glass plate and the other on the lower human leg (shin). The compounds tested were DEET, EBAAP, icaridin, capric acid, lauric acid, geraniol, citriodiol, citronella essential oil and lavender essential oil, all non-proprietary ingredients of widely distributed tick repellent formulations.     

4种植物精油对瓜实蝇毒杀及驱避作用

瓜实蝇 Bactrocera cucurbitae (Copullett)是我国瓜类蔬菜的重要入侵害虫, 为筛选出对瓜实蝇具有毒杀及驱避作用的植物精油, 室内测定了4种植物精油在不同浓度下对瓜实蝇的毒杀及产卵驱避效果, 并进行了田间验证。结果表明:4种植物精油对瓜实蝇成虫的毒杀效果随精油浓度升高而升高, 浓度为7 mg/mL和10 mg/mL的肉桂精油对瓜实蝇的毒杀效果极显著高于其他精油, 处理后24 h瓜实蝇校正死亡率分别为75.9%和100%;雌虫对冬青精油的嗅觉反应率为93.3%, 显著高于紫苏精油和山苍子精油。不同植物精油对雌虫产卵的驱避效果不同，当植物精油浓度为10 mg/mL时, 冬青精油对雌虫的产卵驱避率为69.04%, 显著高于其他精油。田间试验结果显示:不同植物精油对瓜实蝇成虫具有一定防控效果, 但处理间差异不显著, 可能是由于田间环境复杂、植物精油理化性质存在差异等因素导致。     

芒果炭疽病菌的抑菌植物筛选及肉桂油抑菌活性测定

以芒果炭疽病菌抗药性菌株、敏感菌株为研究材料,用生长速率法筛选出了一批高效抑菌植物,大部分植物的丙酮提取物对芒果炭疽病菌有不同程度的抑制作用,其中:肉桂、丁香、藿香的提取物活性最强,在干物质质量浓度为0.025 g/mL下抑制率达100%;芒果炭疽病菌抗药性菌株对肉桂等植物提取物无明显抗性;肉桂油对芒果炭疽病菌敏感菌株(ZJS)和抗药性菌株(JZR)的抑制中浓度(EC50)分别为98.9和71.2 mg/L,而肉桂醛对ZJS和ZJR的EC50值分别为20.7和20.2 mg/L。     

Comparative effects of vetiver oil,nootkatone and disodium octaborate tetrahydrate on Coptotermes formosanus and its symbiotic fauna

The potential of vetiver oil and nootkatone as wood treatments against Coptotermes formosanus Shiraki was examined by assessing the effects on termite tunneling, feeding activity and survival, and the consequences on the symbiont protozoa responsible for wood digestion. Comparisons were made with non-treated wood (control), wood treated with the borate compound Tim-Bor (a commonly used lumber preservative) and absence of a food source (starved termites), using choice and no-choice tests. All wood slices were prepared at the same time using a 10 g liter(-1) solution of each substance and were tested in four different sessions over one year to investigate longevity of the effects. Termites had to tunnel through sand to exploit the food sources, consisting of two wood slices, placed on opposite sides of the experimental enclosure. No-choice tests showed that in the presence of vetiver oil or nootkatone, tunneling activity was always the lowest; wood consumption, termite survival and flagellate numbers and species distribution were significantly different from the control and similar to the results obtained for starved termites and with Tim-Bor-treated wood. Nootkatone negatively affected termites for 12 months and was longer lasting than vetiver oil. In choice tests, when vetiver oil or nootkatone were present, termites exhibited a significant preference for non-treated wood. Our results confirmed both the toxicity and absence of repellency of Tim-Bor. Vetiver oil and especially nootkatone affected Formosan subterranean termites and their protozoa, acting as arrestants, repellents and feeding deterrents, and represent a promising natural alternative for the control of this invasive pest.     

Fumigant activity of (E)-anethole identified in Illicium verum fruit against Blattella germanica

The insecticidal activities of materials derived from the fruit of star anise, Illicium verum, against adults of Blattella germanica were examined by direct contact application and fumigation methods, and compared with those of DDVP, deltamethrin and hydramethylnon. The biologically active constituent of the Illicium fruit was characterized as the phenylpropene, (E)-anethole, by spectroscopic analysis. In a filter paper diffusion test with females, (E)-anethole caused 80.3% mortality at 0.159 mg cm-2 at 1 and 3 days after treatment (DAT), whereas 16.7% mortality at 3 DAT was achieved at 0.079 mg cm-2. DDVP and deltamethrin gave > 90% mortality at 0.019 mg cm-2 at 1 DAT. At 0.009 mg cm-2, DDVP and deltamethrin showed 73.3 and 60% mortality at 1 DAT, respectively, but 93.3 and 76.7% mortality at 3 DAT. Hydramethylnon exhibited 0 and 93.3% mortality at 0.159 mg cm-2 at 1 and 3 DAT, respectively, whereas 6.7% mortality at 3 DAT was observed at 0.079 mg cm-2. In a fumigation test with females, (E)-anethole was much more effective in closed cups than in open ones, indicating that the insecticidal activity of the compound was largely attributable to fumigant action. (E)-Anethole and DDVP caused 100% mortality at 0.398 and 0.051 mg cm-2 4 and 1 h after treatment, respectively. (E)-Anethole showed 46.7% mortality at 0.199 mg cm-2 at 3 DAT, whereas deltamethrin and hydramethylnon at 0.796 mg cm-2 was ineffective for 3-day period. As naturally occurring insect-control agents, the I verum fruit-derived materials described could be useful for managing populations of B germanica.     

Protective action of fenvalerate,deltamethrin, and four stereoisomers of permethrin against black flies (Simulium spp.) attacking cattle

Fenvalerate, deltamethrin, (1R)-cis-permethrin, (1R)-trans-permethrin and (1S)-trans-permethrin, applied topically to the entire body surface of steers at a rate of 1 mg a.i. kg⁻¹, provided 70% or better protection from black flies on cattle for 16, 9, 8, 6 and 6 days, respectively. The (1S)-cis stereoisomer of permethrin was ineffective as a protectant against black flies at a rate of 1 mg a.i. kg⁻¹ when applied as a total body spray. One poly(vinyl chloride) ear tag containing 10% permethrin, in each ear of steers, provided protection from black fly attack for up to 13 days under field conditions. Poly(vinyl chloride) ear tags containing 8% fenvalerate, installed in each ear of steers, did not provide satisfactory protection from black flies under field conditions.     

印楝素乳油不同施用方式对烟粉虱寄主选择和产卵的影响

研究了3%印楝素乳油叶面喷雾和灌根对烟粉虱成虫寄主选择和产卵的影响。10mg/L印楝素乳油叶面喷雾和灌根48h后,寄主选择忌避率分别为82.7%和48.5%,72h后分别为91.0%和61.9%。叶面喷雾48和72h后寄主选择忌避中浓度RC50分别为0.317和0.237mg/L,灌根处理分别为10.301和4.191mg/L。叶面喷雾和灌根后72h的产卵忌避中浓度分别为1.241和5.833mg/L。在不同浓度的多选择试验中,成虫对叶面喷雾或灌根处理植株的选择性与浓度负相关。随印楝素施药浓度的增大和施药后时间的延长其忌避作用增强。     

Laboratory trials of fatty acids as repellents or antifeedants against houseflies,horn flies and stable flies (Diptera: Muscidae)

BACKGROUND: Straight‐chain, saturated fatty acids (particularly C8, C9 and C10) have some known behavioral effects on insects such as mosquitoes, and were tested in combination for potential repellency/antifeedant activity in bioassays against three significant muscoid flies of medical/veterinary importance: houseflies, horn flies and stable flies. RESULTS: Mixtures of C8, C9 and C10 (1:1:1; 15% total actives in formulation) were highly repellent to houseflies and horn flies at or below 1 mg formulation cm^?2. Repellency time varied from < 1 day for houseflies to usually at least 3 days for horn flies. Individual longer‐chain‐length fatty acids were tested, and C11 repelled houseflies for up to 5–8 days, while C12 lasted 2 days. Minimum statistically significant repellency levels of the C8, C9 and C10 mixture (3 h after application) against horn flies were 0.06–0.12 mg cm^?2. A liquid formulation of the 15% C8, C9 and C10 mixture in a silicone oil carrier (at 2.8 mg AI cm^?2) was highly repellent against hungry stable flies in a blood‐feeding membrane bioassay for at least 8 h. CONCLUSION: The low toxicity and reasonable activity and persistence of these carboxylic acids make them good candidates for development as protective materials against pest flies in livestock settings. Copyright © 2009 Society of Chemical Industry     

Repellency and toxicity of aromatic plant extracts against the mosquito Culex pipiens molestus (Diptera: Culicidae)

The insecticidal activities of essential oil extracts from leaves, flowers and roots of aromatic plants against fourth-instar larvae of the mosquito Culex pipiens molestus Forskal were determined. Extracts of Foeniculum vulgare Mill were the most toxic, followed by those of Ferula hermonis Boiss, Citrus sinensis Osbeck, Pinus pinea L, Laurus nobilis L and Eucalyptus spp with LC50 values of 24.5, 44.0, 60.0, 75.0, 117.0 and 120.0 mg litre(-1), respectively. Combination tests between the LC50 and the maximum sub-lethal concentration (MSLC) were determined. Over 20 major components were identified in extracts from each plant species tested. Five essential oils and nine pure components were studied for their repellency against mosquito bites. Terpineol and 1,8-cineole were the most effective against Culex pipiens molestus bites offering complete protection for 1.6 and 2 h, respectively.     

11种植物精油对茶橙瘿螨的触杀和驱避作用研究

分别采用喷雾法和半叶法测定了11种植物精油对茶橙瘿螨的触杀和驱避活性。结果表明, 浓度为1%、0.5%、0.25%、0.125%(V/V)的11种植物精油对茶橙瘿螨都表现出了不同程度的触杀活性。随着作用时间的延长和精油浓度的增加, 其校正死亡率均有不同程度的升高。总体来看, 肉桂精油触杀效果最好, 在不同试验浓度和处理时间条件下校正死亡率均高于其他精油。所试精油对茶橙瘿螨都有一定的驱避作用, 其中百里香等8种精油的驱避率达80%以上。以上结果将为筛选对茶橙瘿螨具有较好防效的新型低毒高效植物源农药提供重要依据。     

芳香植物气味及提取液对茶尺蠖行为的影响

为了明确芳香植物对茶尺蠖Ectropisobliqua的驱避、拒食作用和获得应用于茶园茶尺蠖"推-拉"策略的植物材料,利用"Y"型嗅觉仪室内测定其成虫对芳香植物气味的趋性反应,并采用叶碟法测定芳香植物提取液对其幼虫的拒食作用及营养干扰效果。丁香罗勒、迷迭香、柠檬桉和芸香植株挥发物及甲醇提取液对茶尺蠖雌、雄成虫有显著的驱避效果。猫薄荷、迷迭香和鼠尾草的2 00 mg/mL甲醇提取液对茶尺蠖3龄幼虫表现出显著拒食活性,24 h后的选择性拒食率分别为93.85%、86.00%和77.32%,非选择性拒食率分别为85.77%、87.00%和88.05%。其中,迷迭香处理的幼虫生长率最低,仅为0.12 mg/天,对幼虫的相对取食量、食物利用率和食物转化率等营养指标有影响。研究表明,10种芳香植物中迷迭香具有显著的行为调控功能,是构建茶尺蠖"推-拉"策略的理想材料。     

Disinsection of aircraft with pressure packs containing the pyrethroids,resmethrin and bioresmethrin

Pyrethrins and the pyrethroids, bioallethrin ((+) trans-chrysanthemic acid ester of (±) allethrolone), resmethrin* (5-benzyl-3-furylmethyl (±)-cis,trans-chrysanthemate) and bioresmethrin? (5-benzyl-3-furylmethyl (+)-trans-chrysanthemate) were compared for insecticidal activity against free-flying Aedes aegypti L. in a Peet-Grady chamber using kerosene solutions and an aerosol particle size. The relative potency for kill of female mosquitoes was 1; 2.3; 6.8; 8.0 respectively. In further experiments, resmethrin and bioresmethrin were compared as aerosol formulations in a Comet 4C aircraft using caged and fed female A. aegypti. Both compounds at 0.1% (by wt.) in pressure packs and 35 g of formulation per 100 m³ provided 99% kill. It is suggested that pressure packs containing 0.5% (by wt.) of either compound should be adequate for disinsection of passenger aircraft. However, bioresmethrin would appear to be the compound of choice in view of its greater biological efficiency under laboratory conditions, and consequent probable greater margin of kill in practice.     

Review of anthraquinone applications for pest management and agricultural crop protection

We have reviewed published anthraquinone applications for international pest management and agricultural crop protection from 1943 to 2016. Anthraquinone (AQ) is commonly found in dyes, pigments and many plants and organisms. Avian repellent research with AQ began in the 1940s. In the context of pest management, AQ is currently used as a chemical repellent, perch deterrent, insecticide and feeding deterrent in many wild birds, and in some mammals, insects and fishes. Criteria for evaluation of effective chemical repellents include efficacy, potential for wildlife hazards, phytotoxicity and environmental persistence. As a biopesticide, AQ often meets these criteria of efficacy for the non‐lethal management of agricultural depredation caused by wildlife. We summarize published applications of AQ for the protection of newly planted and maturing crops from pest birds. Conventional applications of AQ‐based repellents include preplant seed treatments [e.g. corn (Zea mays L.), rice (Oryza sativa L.), sunflower (Helianthus annuus L.), wheat (Triticum spp.), millet (Panicum spp.), sorghum (Sorghum bicolor L.), pelletized feed and forest tree species] and foliar applications for rice, sunflower, lettuce (Lactuca sativa L.), turf, sugar beets (Beta vulgaris L.), soybean (Glycine max L.), sweet corn and nursery, fruit and nut crops. In addition to agricultural repellent applications, AQ has also been used to treat toxicants for the protection of non‐target birds. Few studies have demonstrated AQ repellency in mammals, including wild boar (Sus scrofa, L.), thirteen‐lined ground squirrels (Ictidomys tridecemlineatus, Mitchill), black‐tailed prairie dogs (Cyomys ludovicainus, Ord.), common voles (Microtus arvalis, Pallas), house mice (Mus musculus, L.), Tristram's jirds (Meriones tristrami, Thomas) and black rats (Rattus rattus L.). Natural sources of AQ and its derivatives have also been identified as insecticides and insect repellents. As a natural or synthetic biopesticide, AQ is a promising candidate for many contexts of non‐lethal and insecticidal pest management. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.     

Experience-altered oviposition responses to a neem-based product, Neemix, by the diamondback moth, Plutella xylostella

The oviposition responses of the diamondback moth, Plutella xylostella L., to Neemix 4.5, a neem-based oviposition repellent/deterrent, with or without previous experience were studied in the laboratory on plain aluminum foil sheets, on aluminum foil sheets coated with cabbage juice, and on cabbage plants. In the plain aluminum foil sheet experiment, the females without prior experience of Neemix (inexperienced females) deposited more eggs (66.2%) on sections with untreated sheets than on sections with Neemix-treated sheets (33.8%), indicating that the inexperienced females were significantly repelled and/or deterred by Neemix. In contrast, the Neemix-experienced females deposited more eggs (69.2-69.7%) on sections with Neemix-treated sheets than on sections with untreated sheets (30.3-30.8%), implying that the females were not repelled and/or deterred by Neemix following an experience. In the tests using egg-laying sheets coated with cabbage juice or with cabbage juice plus Neemix, the inexperienced females deposited more eggs (63.8%) on the sections with sheets treated with cabbage juice only than on the sections with sheets coated with cabbage juice and Neemix (36.2%), indicating that inexperienced females were repelled and/or deterred by Neemix. Similarly, Neemix-experienced females deposited more eggs (62.2-65.6%) on the sections with sheets treated with cabbage juice plus Neemix than on the sections with sheets treated with juice only (34.4-37.8%), suggesting that the females were not repelled and/or deterred by Neemix following an experience. On cabbage plants, inexperienced females oviposited similar numbers of eggs on both Neemix-treated (50.8%) and untreated plants (49.2%). However, the Neemix-experienced females oviposited more eggs on the plants treated with Neemix (56.3%) than on untreated plants (43.7%), indicating that the females were attracted by Neemix-treated plants following an experience. The significance of this study for applications of insect repellents/deterrents in pest management is discussed.     

Bioactivity against Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) of Cymbopogon citratus and Eucalyptus citriodora essential oils grown in Colombia

BACKGROUND: Essential oils isolated from Cymbopogon citratus (DC) Stapf. and Eucalyptus citriodora Hook grown in Colombia were analysed by gas chromatography–mass spectrometry (GC‐MS) and tested for repellent activity and contact toxicity against Tribolium castaneum (Herbst.) (Coleoptera: Tenebrionidae). RESULTS: The main components of C. citratus oil were geranial (34.4%), neral (28.4%) and geraniol (11.5%), whereas those of E. citriodora were citronellal (40%), isopulegol (14.6%) and citronellol (13%). The mean repellent doses after 4 h exposure were 0.021 and 0.084 mL L^?1 for C. citratus and E. citriodora oils respectively—values lower than that observed for the commercial product IR3535 (0.686 mL L^?1). CONCLUSION: These studies showed the composition and repellent activity of essential oils of C. citratus and E. citriodora, suggesting that these are potential candidates as insect repellents. Copyright © 2010 Society of Chemical Industry     

Grass weed control with herbicide-treated crop seeds

Fluazifop-butyl applied in lung oil at rates of 4.4 to 0.5 g a.i. kg^?1 soybean seeds was evaluated in the glasshouse for control of Eleuisine indica. Soybean seeds pretreated with herbicide at 4.4 to 2.1 g a.i. kg^?1 gave 100% control of E. indica at the highest sowing rate of four seeds per pot and 90 to 80% control when sowed at one seed per pot. Soybeans were not injured by the seed treatment. Cotton seeds pre-treated with fluazifop at 2.2 g a.i. kg^?1 seeds and sown 4 cm apart in a row across a 20 ± 20cm tray of soil containing seeds of Echinochloa crus-galli produced a weed-free band 12 cm wide centred on the row of cotton, without injury to cotton. CGA-82725 (2-propynyl 2-(4-((3, 5-dichloro-2-pyridinyl)oxy)phenoxy) propanoate) at 2–3 g a.i. kg^?1 seeds was as effective as 4–4 g fluazifop-butyl in controlling E. indica. but growth of soybean was retarded. Sethoxydim gave less control than fluazifop butyl at comparable rates and did not injure soybeans.