摘要:

AbstractPetroleum oil sprays are used on citrus to control California red scale (Aonidiella aurantiiMaskell), but may have phytotoxic effects on trees and fruit. As part of a programme to establish improved specifications for spray oils for South Australia, three oils with various 50%‐distillation temperatures were applied to trees each month from October to May to observe their effects on crop yield. Some treatments were applied once in each of three consecutive seasons while others were applied only once in the first season. The 50%‐distillation temperatures of the three oils were 211, 224 and 240°C at 10 mmHg. The oils caused significant reductions in yield, and caused or accentuated alternate cropping cycles. The higher the 50%‐distillation temperature of the oil, the greater the effect. The time of application was also important. The greatest yield reductions (expressed as two averages) occurred when the oils were sprayed in November; the tendency to alternate cropping increased with the month of application from December to May. For the oil with the highest 50%‐distillation temperature, the yield reductions were about 30%, and the yields from trees in a severe alternate cropping cycle, in the ‘light crop’ year, were as low as 25% of those on uns

ISSN:0031-613X    

DOI:10.1002/ps.2780120602

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractPetroleum oils sprays are used as pesticides on citrus in South Australia to control California red scale (Aonidiella aurantiiMaskell), but may have phytotoxic effects on trees and fruit. As part of a programme to establish improved specifications for spray oils for South Australia, three oils with different 50 %‐distillation temperatures were applied to trees each month from October to May for two seasons in order to observe their effects on fruit quality. The 50 %‐distillation temperatures of the three oils were 211, 224 and 240°C at 10 mmHg (in order of increasing molecular weight) and the oils are subsequently referred to as the 211, 224 and 240 oils. The 224 and 240 oils significantly reduced the amounts of sugar and acid in the juice, and delayed and inhibited colouring. These effects increased in severity, the closer to harvest the trees were sprayed and the higher the distillation temperature of the oil. The 240 oil prevented full colour development, and caused ‘re‐greening’ if sprayed later than February. Oil sprays applied to the same trees in the following season caused similar effects. However, if oil sprays were omitted in the following season, there was no residual effect, of the previous season's spray, on the sugar and acid contents or the colour of the fruit. Individual fruit weight was not affected in the first spraying season, but there was an increase in the average individual fruit weight in the second season, regardless of whether a second spray was applied that season or not. The effect was more severe, the closer to harvest the trees were sprayed and the greater the distillation temperature of the oil. The effects on yield resulted from a change in the number of frui

ISSN:0031-613X    

DOI:10.1002/ps.2780120603

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractPetroleum oil sprays are used as pesticides on citrus to control California red scale (Aonidiella aurantiiMaskell), but may have phytotoxic effects on trees and fruit. As part of a programme to establish improved specifications for spray oils for South Australia, three oils with different 50 %‐distillation temperatures were applied to trees each month from October to May to observe their effects on leaf and fruit drop. The 50%‐distillation temperatures of the three oils were 211, 224 and 240°C at 10 mmHg (in order of increasing molecular weight). The oils caused significant leaf drop. The higher the 50%‐distillation temperature of the oil, the greater the leaf drop. Most leaf drop was caused when natural leaf drop was greatest. Oils applied from October to February caused severe leaf drop for periods of about 1–2 months, while oils applied from March to May caused severe leaf drop for up to 6 months or more. There was also a tendency for oils with a lower 50%‐distillation temperature to cause leaf drop sooner after spraying than oils with a higher 50%‐distillation temperature. Significant fruit drop was caused in only a few treatments, but the maximum fruit drop was less than 5% of the total fruit number and of little consequence when compared with the effects of oils on yield through reduced fruit set. Visually, a significant proportion of the total number of leaves present fell in many of the oil spray treatments, and the rate of disappearance of the oil film was directly related to the 50%‐distillation temperature of the oil, and to the

ISSN:0031-613X    

DOI:10.1002/ps.2780120604

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractField tests, in which several insecticides were applied at equal rates by ground sprayer to oats, rye and alfalfa, showed that residues 1 h after application were much lower for highly volatile compounds than for those of lower volatility. Varying the distance from spray release to target canopy from 10 to 40 cm did not significantly affect the deposits. Results indicate that applying insecticides with a vapour pressure greater than about 10−4mmHg (20°C) in aqueous media is very inefficie

ISSN:0031-613X    

DOI:10.1002/ps.2780120605

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractAn antifeeding (feeding deterrent) response by first‐ and fifth‐instar larvae ofPieris brassicaewas shown to be significant at sub‐lethal levels of cypermethrin and permethrin, using leaf‐discs treated with the pyrethroids by dipping. Permethrin was slightly more effective than cypermethrin both as an insecticide and as an antifeedant against fifth‐instar larvae, but the reverse order of effectiveness was observed, with a marked difference in mortality, against newly‐hatched larvae. When 1‐day‐old fifth‐instar larvae were continuously given leaf discs treated with a solution of the pyrethroid (1 mg litre−1), up to the time of pupation, both cypermethrin and permethrin induced a significant extension of the larval period, with a reduction in the maximum larval and pupal weights, as well as a reduction in the total leaf‐area consumed. However, at higher levels of both pyrethroids, lowering the temperature induced some irritancy, as indicated by regurgitation and frequent uncoordinated wriggling movements of the fifth‐instar larvae. The advantages of cypermethrin as a protectant and as an antifeedant over p

ISSN:0031-613X    

DOI:10.1002/ps.2780120606

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractSeven chloraniformethan analogues, which were predicted, on the basis of the quantitative Hansch analysis performed previously, to be as active as the parent compound against barley powdery mildew (Erysiphe graminis), were prepared. Their activity as leaf sprays againstE. graminiswas much lower than that calculated using the regression equations, indicating that the Hansch analysis is not a suitable method for predicting fungitoxicity in this chloraniformethan series of compounds.

ISSN:0031-613X    

DOI:10.1002/ps.2780120607

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe metabolism of the carbamate insecticide bendiocarb (2,2‐dimethylbenzo‐1, 3‐dioxol‐4‐yl methylcarbamate) has been investigated in male and female rats and in a male human volunteer using radiolabelled material. The compound was rapidly and extensively absorbed and completely metabolised following oral administration. In man, absorption was complete,>99% of the dose being excreted in the urine within 22 h. In the rat,>86% of the radiolabel was excreted in the urine within the first 24 h. Faecal excretion from the rat was minor (3–8% of dose) and a small amount of the compound (1–3%) was metabolised and excreted as [14C]carbon dioxide. The major metabolic pathway in both species involved cleavage of the carbamate ester group to yield the phenol,2,2‐dimethylbenzo‐1, 3‐dioxol‐4‐ol (I). This metabolite, occurring as sulphate and glucuronide conjugates, accounted for more than 95% of the dose excreted by the human volunteer. In man, small amounts of conjugates of 2, 2‐dimethylbenzo‐1, 3‐dioxol‐4‐ylN‐(hydroxymethyl)carbamate (II) were also found in early samples. In the rat, the metabolism was more complex with the formation of small amounts of conjugates of II and several minor metabolites, thought to be ring‐hydroxy

ISSN:0031-613X    

DOI:10.1002/ps.2780120608

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA sensitive and specific method for the determination of the bendiocarb metabolite 2, 2‐dimethylbenzo‐1, 3‐dioxol‐4‐ol (I) in human urine has been developed. The method can be used to estimate the amount of bendiocarb absorbed by personnel if they become exposed to the insecticide during manufacture and spraying. Urine is collected for 16 h after the period of exposure to bendiocarb and the total volume of urine voided is measured. The urinary metabolite I occurs in conjugated form and is released by enzymic hydrolysis. The free I is extracted from the urine and analysed by gas chromatography/mass fragmentography. Deuterated I is used as an internal standard and is added to the urine sample prior to the hydrolysis procedure. Determination is possible at levels of 1 μg of I ml−1of urine. Knowing the total volume of urine voided, the amount of bendiocarb absorbed can be calculated. The method can determine the absorption of 1 mg of bendiocarb and will detect absorption below

ISSN:0031-613X    

DOI:10.1002/ps.2780120609

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe biological effectiveness of deposits of binapacryl applied by a single high pressure nozzle was compared with similar deposits applied by twin low‐pressure nozzles. Equal foliar deposit densities were obtained from the two systems but the single nozzles gave marginally better control of apple powdery mildew and fruittree red spider mit

ISSN:0031-613X    

DOI:10.1002/ps.2780120610

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractAn investigation was made of the action of the juvenile hormone analogues (JHAs) methoprene (ZR‐515) and 3‐[5‐(4‐ethylphenoxy)‐3‐methylpent‐3‐enyl]‐2, 2‐dimethyloxirane (R‐20458), and the insecticides chlorpyrifos and methomyl, when applied, separately or in combination, to the late insect stages of susceptible (S) and aminocarb‐resistant (Rm) strains ofSpodoptera littoralisBoisd. Sixth‐instar larvae of the Rmstrain showed detectable levels of cross‐resistance to chlorpyrifos, methomyl and R‐20458. However, cross‐resistance to methoprene was less pronounced in the Rmstrain. Treatment of the same instar with the ED50of methoprene produced an appreciable level of sterility in the S strain, but this level decreased in the Rmstrain. Similar treatment with R‐20458 caused a lower level of sterility in the S strain and the Rmstrain was less affected. In the S strain, the ED25of either chlorpyrifos or methomyl when applied simultaneously with the ED25of R‐20458, produced an antagonistic effect and the Rmstrain was more capable of resisting the joint action of these compounds. The treatment, ED25chlorpyrifos + ED25methoprene produced an additive effect on the S strain, while the Rmstrain tolerated their combined action. Nevertheless, the treatment, ED25methomyl + ED25methoprene produced additive effects on both the S and Rmstrains. The prepupae of the Rmstrain tolerated the action of the insecticides methomyl and chlorpyrifos. A similar pattern of cross‐resistance was also detected against the action of the two hormones at the ED25level, while at the ED25level, both the S and Rmstrains were almost equally sensitive to the action of the two juvenoids. Chlorpyrifos‐JHA combinations produced additive effects on prepupae of the S strain while the Rmstrain completely resisted their joint action. Methomyl‐JHA combinations produced high potentiation in the S strain, but the Rmstrain remained insensitive to their joint action. Detectable levels of tolerance to the action of chlorpyrifos and methomyl at the ED25and ED50levels were indicated in 2‐day‐old pupae of the Rmstrain. This was less evident in the case of JHAs, particularly methoprene, which was to some extent equally effective on both strains; the reproductive ability of the S and Rmstrains was highly affected by this compound. The pupae of the Rmstrains were equally as affected as those of the S strain by the combination ED25chlorpyrifos+ ED25R‐20458. Nevertheless, the two strains showed antagonism to the action of chlorpyrifos with methoprene. A high level of potentiation was produced in the S strain to the combination of methomyl and R‐20458 but the Rmstrain was able to withstand their combined action. Of interest in this respect was the action of the combination of methomyl and methoprene, for which high levels of potentiation were detected in pupae of the S and Rmstrains. This combination also Produced a high percent

ISSN:0031-613X    

DOI:10.1002/ps.2780120611

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY