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1.
Laboratory experiments gave useful indications of the effectiveness of insecticide treatments to control larvae of frit fly ( Oscinella frit L.). Lightly infested field experiments provided confirmatory evidence. Several seed treatments, insecticide granules combine-drilled with the seed and post-emergence sprays were very effective. The feasibility of delivering granules with seed must be confirmed for each granular formulation. Post-emergence sprays were most effective if applied at approximately the time of oviposition but several also gave a strong residual effect if applied earlier and a remedial effect if applied after larval establishment in the seedlings. More detailed conclusions are discussed.  相似文献   

2.
《Crop Protection》1987,6(5):334-340
Eight contact and three systemic insecticides, and an enriched neem extract were tested for the control of sorghum head bug, Calocoris angustatus Leth. at the ICRISAT Center. The insecticides were applied at the complete-anthesis and milk stages (at 500 1/ha) with a knapsack sprayer. On the basis of effectiveness of head bug control, grain yield and 1000-grain mass, carbaryl (at 500 g a.i./ha) was the most effective insecticide followed by fenvalerate (at 50 g a.i./ha), and chlorpyrifos (at 250 g a.i./ha). Among the systemic insecticides, demeton-S-methyl (at 250g a.i./ha), was the most effective. Demeton-S-methyl and dimethoate were also effective for the control of other head bug species—Eurystylus bellevoyei Put. and Reut. and Campylomma sp. Plots sprayed with demeton-S-methyl gave higher grain yields than those treated with carbaryl, which was the best contact insecticide. Two sprays of carbaryl (at 500g a.i./ha) applied at the complete-anthesis and milk stages have been found to be effective for head bug control. Dichlorvos, fenitrothion and monocrotophos were highly phytotoxic and resulted in burning and drying of entire leaves. Dimethoate resulted in a slight drying of leaf tips and margins.  相似文献   

3.
《Crop Protection》1988,7(1):34-38
Fungicide seed treatment using benomyl+captan, combined with postemergence sprays of the insecticides chlorpyrifos and omethoate increased herbage yield 10 weeks after sowing in five of eight sowings of Italian and perennial ryegrass. At one sowing, five other fungicide seed treatments—carbendazim+captan, thiabendazole+captan, thiabendazole+thiram, thiabendazole+metalaxyl, and drazoxolon—combined with the insecticide sprays, also increased yield. The insecticides were shown to give good control of shoot-fly larvae, but the yield response to insecticides alone was not as great as that from the combined treatment. As fungicide seed treatment alone increased seedling emergence at one sowing only, possibly the fungicides improved seedling vigour by reducing sub-lethal attacks from soil-borne diseases. The combination of a fungicide and insecticide seed treatment was used at five sowings with no effect.  相似文献   

4.
In the 2014 and 2015 crop seasons, the efficacies of different types, rates and combinations of mineral oil and insecticide foliar sprays for reducing Potato virus Y (PVY) spread were tested in controlled field trials in New Brunswick (NB), Canada. Experimental plots were planted with certified PVY-free Goldrush, supplemented with known virus-infected seed to raise PVY inoculum to 2.3% and 3% at the beginning of the 2014 and 2015 seasons, respectively. Treatments consisted of mineral oil-only sprays at different application rates, insecticide-only sprays of differing numbers, and several combined mineral oil and insecticide spray regimes, all compared to a no-spray control treatment. PVY spread to 18% (2014) and 22% (2015) of initially virus-free plants in no-spray control plots, with significant reductions observed in PVY spread in several treatments. Greatest PVY reductions, as low as 4% (2014) and 12% (2015), were in combined mineral oil and insecticide spray treatments, followed by oil-only sprays; while insecticide-only sprays did not significantly reduce PVY spread. As well as measuring PVY spread to marked test plants and randomly collected post-harvest tuber sample from the plots, exhibited similar treatment pattern for PVY incidence. Multiple logistic regression modeling confirmed the relative efficacy of combined oil and insecticide sprays for reducing PVY spread, while accounting for variable inoculum and aphid factors. Modeling also highlighted the importance of planting low-PVY seed initially, and of early application of foliar sprays. Local best management practice recommendations for reduction of in-field PVY spread were discussed.  相似文献   

5.
The ability of liquid formulations of synthetic pyrethroid insecticides, a carbamate insecticide, and mineral oils, to limit the spread of non-persistent viruses in lilies, tulips, hyacinths and bulbous irises, was studied under field conditions that favoured rapid virus spread. Bait plants were sprayed and virus source plants were not. Substantial control was consistently achieved by weekly sprays of pyrethroids in moderate amounts of active ingredient. No significant additional control was obtained by increasing rates of application, whereas at low rates the control was inadequate or very variable. Control was generally improved by spraying twice a week, whereas fortnightly spraying was inadequate. Fenvalerate sprays gave slightly better control than permethrin in lilies and bulbous irises. The carbamate insecticide gave inconsistent or no control. Pyrethroids were on average only half as effective as mineral-oil sprays. Application of pyrethroids, unlike that of oil sprays, did not reduce bulb yields. The use of pyrethroids to affect probing behaviour of aphids, and consequently its potential to limit the spread of non-persistent viruses in ornamental bulb crops, is discussed.  相似文献   

6.
The use of the organophosphate malathion (mercaptothion) in protein bait sprays for fruit fly (Diptera: Tephritidae) control in South African citrus orchards will slowly phase out due to lower tolerances of residues of this insecticide on fruit destined for export markets. As such, a replacement for malathion is being sought. In this study, efficacy of six insecticides: abamectin, alpha-cypermethrin, fipronil, imidacloprid, spinosad and tartar emetic, in combination with HymLure (a protein based attractant), was determined in laboratory assays on female Mediterranean fruit flies, Ceratitis capitata Wiedemann. Three concentrations of HymLure (0.8%, 2% and 10%) were tested with five concentrations of each insecticide. Thereafter the efficacy of the most promising attractant–insecticide combination was determined and compared in the laboratory and in a citrus orchard to standard HymLure–malathion (mixture of 0.8% HymLure and malathion at 875 ppm, diluted in water) and GF-120 (5%, diluted in water) treatments for C. capitata and Ceratitis rosa Karsch (Natal fly). Among the insecticides tested, spinosad was found to induce the highest fly mortality in a shorter time over the whole range of concentrations tested, with mortality reaching above 80% after 24 h when combined with a solution of either 2% HymLure or 10% HymLure. Fipronil, tartar emetic and imidacloprid did not act as fast but were also effective, especially when combined with higher concentrations of HymLure. A mixture of 2% HymLure and spinosad at 48 ppm was found to be effective against both C. capitata and C. rosa in both laboratory and field tests and could therefore be recommended as a replacement for malathion-based bait sprays.  相似文献   

7.
Avoidable losses and economic injury levels (EILs) were computed for the sorghum head bug, Calocoris angustatus Leth., on three cultivars during three rainy seasons (1985–1987) at ICRISAT. Grain yield in plots protected with 2–5 insecticide sprays (carbaryl at 500 g a.i./ha) between the half-anthesis and the dough stage was significantly higher than in untreated plots, with cost-benefit ratios > 1. Plots that were not protected at half-anthesis and/or complete-anthesis, and at milk and dough stages, suffered a significant loss in yield. Bug damage spoiled the grain quality in terms of germination, 1000-grain mass, grain hardness and percentage floaters. Three to four sprays between complete-anthesis and the dough stage prevented a significant reduction in grain quality. Head bug density at half-anthesis, complete-anthesis, milk and dough stages was significantly and negatively associated with grain yield. Bug density at different stages explained 43–94% of the variance in yield. Direct effects of bug numbers at the milk stage and the indirect effects of head bug density at other stages through the milk stage contributed towards maximum reduction in yield. Maximum avoidable losses were recorded in cultivar ICSV 1 (88·6%), followed by CSH 1 (69·9%), and CSH 5 (53·9% in 1986 and 55·0% in 1987). Loss in grain yield/ha due to one insect/panicle at half-anthesis and that based on natural increase, were 548 and 232 kg in CSH 5 during 1986 and 1987, respectively, 251 kg in ICSV 1, and 77 kg in CSH 1. EILs based on a cost-benefit ratio of 1:1 ranged from 1·3–1·4 insects/panicle for CSH 1, 0·4 for ICSV 1, and 0·4–0·6 and 0·2–0·4 for CSH 5 during 1986 and 1987, respectively. Simple cost estimates for insecticide sprays and the resultant saving in grain yield are a useful tool for decision-making in pest management.  相似文献   

8.
Field experiments were conducted during the rainy seasons of 2009 and 2010 for the management of the major diseases of mungbean, namely, wet root rot (Rhizoctonia solani), cercospora leaf spots (Cercospora canescens and Pseudocercospora cruenta) and yellow mosaic (Mungbean Yellow Mosaic Virus) by using different combinations of an insecticide, fungicide, and bio-formulation as seed treatment, with or without foliar sprays. A combination of seed treatment with thiamethoxam (Cruiser™) at 4 g kg−1, carboxin (Vitavax™) at 2 g kg−1 and Pusa 5SD (Trichoderma virens) at 4 g kg−1 followed by simultaneous foliar sprays of thiamethoxam (Actara™) 0.02% and carbendazim (Bavistin™) 0.05% at 21 and 35 days after sowing resulted in the highest seed germination and grain yield in mungbean with the lowest intensities of cercospora leaf spots and mungbean yellow mosaic, and moderate incidence of wet root rot. The lowest whitefly population was also observed in this treatment during all stages of the crop. The treatment combinations having Pusa 5SD as seed treatment provided the lowest wet root rot incidence. Two sprays were superior to single spray for all variables recorded, but in combination with seed treatment, single spray was found to be more cost effective as it obtained the highest return per rupee of input. Use of T. virens based bio-formulation Pusa 5SD with insecticide thiamethoxam has been effectively demonstrated for the first time along with fungicides Bavistin and Vitavax for the management of the major diseases of mungbean.  相似文献   

9.
Six insecticides (terbufos, chlorpyrifos, ethoprophos, phoxim, bendiocarb and lindane) were tested against sugar-cane wireworm Agrypnus variabilis (Candèze) in maize. The first five insecticides were applied at 0·25, 0·5 and 0·75 kg a.i./ha (2·27, 4·55 and 6·82 g a.i./100 metres of row) while lindane was applied at the registered rate of 0·29 kg a.i./ha (2·64 g a.i./100 metres of row). In addition, bendiocarb was applied as a seed treatment at the rates of 4000 and 6000 ppm. The insecticides were applied at planting as insecticide/fertilizer mixtures in 18 cm wide bands, 2–3 cm below the soil surface and 3–5 cm above the seed. The minimum effective rates were terbufos 0·25 kg a.i./ha, lindane 0·25 kg a.i./ha and chlorpyrifos and ethoprophos both at 0·5 kg a.i./ha. These treatments gave at least 5 weeks' residual control. The bendiocarb seed treatments were phytotoxic. No residues were detected in the cobs or grain at the minimum effective rates of the terbufos, chlorpyrifos or ethoprophos treatments. The positive linear relationship between plant population and yield showed that for every 1% loss in plant stand below the optimum range of 60 000–65 000 plants/ha, there is a 0·72-0·74% loss in grain yield respectively. Control measures would be economically justified with only a 2·3% reduction in plant stand (assuming $20/ha for cost of control and $150/tonne for maize).  相似文献   

10.
Sex pheromone trap catches, galling damage, yield and growth were recorded over up to three successive seasons (2010–2012) in large replicated plots treated versus untreated with synthetic pyrethroid (SP) insecticides for blackcurrant leaf midge Dasineura tetensi control in eight established commercial blackcurrant plantations in southern England. The aim was to determine whether or not the current practice of spraying insecticides against the pest in commercial fruiting plantations is justified. In two separate small plot replicated experiments (in 2010 and 2011, respectively) in plantations which had been cut down in the previous winter, galling damage and shoot growth were recorded in the vigorous regrowth in plots treated versus untreated with SP insecticides against 1st, 2nd or both D. tetensi generations. Cutting down bushes to ground level in this way is a common way of regenerating plantations.In the experiments in the established fruiting plantations, applying sprays of insecticides led to substantial reductions in numbers of adult D. tetensi caught in sex pheromone traps (by 72% on average) and reductions in galling damage (by 75% on average) but did not result in increases in yield or statistically significant increases in shoot growth. Multiple possible mechanisms of yield compensation are discussed. In the experiments in the cut-down bushes where the galling was intense, the D. tetensi damage resulted in severe (59%) stunting and multiple branching of the regrowth which was weak and thin. Sprays against the 2nd generation only partially reduced stunting (to 24%).The results of this work call into question the current commercial practice of controlling this pest in established commercial plantations with sprays of insecticides: as significant increases in yield or growth did not result in these experiments, the effects of the sprays was largely cosmetic. Further, broad spectrum synthetic pyrethroid insecticides are likely to have persistent adverse effects on the natural enemies of D. tetensi. However, the work showed that control in re-growing cut-down plantations, and by analogy in young establishing plantations, is vital, as well as the value of the D. tetensi sex pheromone traps for timing sprays of insecticides.  相似文献   

11.
The synthetic pyrethroid fenvalerate (Sumicidin® 20E1) has been tested in 64 field trials of the control of bollworms on rainfed and irrigated cotton in Maharashtra, Tamil Nadu, Punjab, Andhra Pradesh, Haryana, Rajasthan, Madhya Pradesh, Gujarat and Karnataka. Fenvalerate, at dose levels of 50–150 g a.i./ha, was tested on 15 varieties of cotton, with long, extra-long, short and medium staples. From two to nine sprays were applied at intervals of 7–30 days, depending on whether the insecticide was sprayed according to a calendar-based schedule or when needed. Fenvalerate was compared with conventional insecticides such as carbaryl, monocrotophos, endosulfan and phosalone, and also with the synthetic pyrethroids permethrin, cypermethrin and deltamethrin. The percentage of bollworm-infested plants in the fenvalerate-treated plots ranged from zero to 21·8% and in the untreated plots was up to 100%. With conventional pesticides the maximum level of infestation was 97·2%. Increases in yield of seed cotton from fenvalerate-treated plots over those from plots treated with conventional pesticides were 54%, 57%, 67%, 84%, and 86% over monocrotophos, carbaryl, quinalphos, phosalone and endosulfan, respectively, representing increases of 791–1046 kg/ha.  相似文献   

12.
The control of the olive fruit fly Bactrocera oleae (Gmelin) is based on insecticides that are usually applied as bait sprays. Large-scale field experiments were conducted in the Kolymvari region of Crete (Greece) to evaluate the efficacy of several bait spray solutions against the fly that were applied at the recommended spraying volume per hectare (or 300 ml per treated tree), compared applications at volumes reduced by two and three fold (150 and 100 ml, respectively). The trophical attractant (hydrolysed protein at 75% w/w) that was used was mixed with alpha-cypermethrin, thiacloprid, thiacloprid + deltamethrin or dimethoate, and these formulations were tested during three successive summers (2012–2014) according to European Plant Protection Organisation (EPPO) standards. The products were alternated with one another over time in the experimental plots. The results indicated that all of the bait spraying solutions of the tested products were effective against B. oleae at all of the doses tested and resulted in significantly lower olive fly populations compared with the standard recommended dose, which was indicated by the fly catches in the nets of McPhail traps within the experimental plots. The percentages of live infestations of B. oleae were very low (<2%, except in 2013 due to a very low olive fruit yield), as was the number of applications each year, which was 6–7 and did not differ among treatments. The benefits of this concept in the management of the pest and potential future improvements of the method are discussed.  相似文献   

13.
This study investigated the correlation between insect mortality and insecticide residue levels in rice grain during the developing stages and at harvest, and also determined the relative toxicities of three insecticides, monocrotophos (Azodrin 16·8 EC), lindane (Agrocide 26 DP), and carbaryl (Sevin 85 WP) to Leptocorisa oratorius (Fab.), (Hemiptera: Alydidae). The insecticides were applied on field plots at 0·75 kg a.i./ha at the start of the milk stage of the developing grains. Sampling was conducted at 2 hours and 1, 2, 3, 4 and 5 days after spraying, which covered the milk stage to the soft dough stage. Mortality of insects exposed to the treated grain, the residue analysis of the treated grain during development and at harvest, and the LD50s of the insecticides were determined. Monocrotophos was the most effective insecticide against the rice bug; lindane provided control for only one day; carbaryl was ineffective. Maximum residue levels of lindane and carbaryl in the harvested grains were below the established tolerance limits provided by FAO/WHO. There is no established tolerance for monocrotophos in rice.  相似文献   

14.
Laboratory and field/pot experiments were conducted to determine the effect of two insecticides, fipronil and pyriproxyfen, on growth, symbiotic properties (nodulation and leghaemoglobin content), amount of N and P nutrients in plant organs, seed yield and seed protein of pea plants. In addition, the role of the most promising fipronil and pyriproxyfen tolerant Rhizobium leguminosarum strain MRP1 having plant growth promoting traits such as, production of phytohormones and siderophores, was also assessed in the presence and absence of both insecticides. Generally, fipronil and pyriproxyfen at the tested rates (recommended and higher doses) decreased the growth of both R. leguminosarum inoculated or uninoculated pea plants. Of the various concentrations of the two insecticides, pyriproxyfen at all concentrations in general, showed comparatively more severe toxicity to pea plants by decreasing plant biomass, symbiotic attributes, nutrients (nitrogen and phosphorus) uptake, seed yield and grain protein over the uninoculated control. The sole application of 3900 μg pyriproxyfen kg−1 soil (three times the recommended dose) showed the highest toxicity and decreased the root nitrogen, shoot nitrogen, root phosphorus, shoot phosphorus, seed yield and grain protein by 20%, 27%, 25%, 29%, 15% and 2% respectively, compared to the control. Interestingly, when the inoculant strain MRP1 was used with any concentration of the two insecticides, it significantly (P ≤ 0.05) increased the measured variables (plant dry weight, nodule numbers, dry nodule biomass, leghaemoglobin, nitrogen and phosphorus uptake, seed yield and grain protein) when compared to the plants grown in sandy clay loam soils treated solely (without inoculant) with the same individual treatment of each insecticide. For instance, three times the recommended dose of pyriproxyfen with strain MRP1 showed a highest stimulatory effect and increased the root nitrogen, shoot nitrogen, root phosphorus, shoot phosphorus, seed yield and grain protein by 108%, 124%, 119%, 153%, 112% and 6% respectively, compared to the plants grown in soil treated solely with three times the recommended dose of pyriproxyfen.  相似文献   

15.
《Crop Protection》1986,5(2):109-113
Injury to the leaves of sugar-beet seedlings caused by the mining of Pegomya betae larvae was greatly decreased by applying insecticide granules in the furrow with the seed: carbofuran, carbosulfan, terbufos and aldicarb were very effective but bendiocarb was only partially effective. Carbosulfan applied as a band spray along the row was less effective than the better granule treatments, while band sprays of gamma-HCH, quinalphos and oxamyl were ineffective or even increased the incidence of damage.  相似文献   

16.
两种悬浮种衣剂对燕麦蚜虫及红叶病的防治效果   总被引:1,自引:2,他引:1  
为给种衣剂在燕麦上的推广应用提供依据,研究了吡虫啉和噻虫嗪两种种衣剂对燕麦蚜虫及红叶病的田间防治效果及增产作用.结果表明,两种种表剂以4~6 mL/kg种子剂量一次性包衣后,对燕麦蚜虫和红叶病均有较好防效,在燕麦扬花期对麦蚜的防效大于50%,成熟期对红叶病的防效也在43%以上,增产效果显著.相比而言,吡虫啉种衣剂防治效果优于噻虫嗪.  相似文献   

17.
Summary Seed tubers grown in the northern mountain region — the Golan Heights — were as productive as imported seed tubers. In cvs. Blanka and Désirée, both the locally grown and the imported seed tubers were similar when yield components and tuber fresh weight are considered. In Up-to-Date, the locally grown seeds produced higher yields of marketable tubers (over 60 g/tuber) than those imported. Désirée seed tubers grown for two generations in the Golan Heights did not differ significantly in their productivity as compared with common Golan seeds and with imported ones. Seed tubers harvested from plots which were protected by means of white coarse nets and weekly sprays with insecticides, were virtually virus-free and were used for growing commercial seeds in the Golan. The use of this method for seed multiplication is suggested. Contribution from the Agricultural Research Organization. The Volcani Center, Bet Dagan, Israel. No 137-E, 1981 Series.  相似文献   

18.
Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is a global pest of citrus and vector of Candidatus Liberibacter, a bacteria that causes huanglongbing or greening, a devastating disease of citrus. Mature citrus trees are dormant in winter and produce most new shoots in spring, followed by sporadic canopy growth in summer and fall. Young shoots are required for oviposition and nymphal development, but adults can survive and overwinter on hardened leaves. Surviving adults reproduce in spring shoots and their progeny are probably responsible for a large portion of disease spread as they disperse to search for food. Therefore, foliar sprays of broad-spectrum insecticides applied to mature trees in winter were evaluated in a commercial citrus orchard as tactic to reduce pest populations and insecticide use in spring and summer when beneficial insects are most active. A single spray of chlorpyrifos (2.8 kg a.i. ha−1) in January 2007 reduced adult psyllids an average of 10-fold over six months compared to untreated trees. The following year, differences with the untreated control averaged 15-fold for over five months following a single spray of chlorpyrifos, fenpropathrin (0.34 kg a.i. ha−1), or oxamyl (1.12 kg a.i. ha−1) applied in January. Spiders, lacewings and ladybeetles were equally abundant during the growing season in both treated and untreated trees both years (P = 0.05). Thus foliar sprays of broad-spectrum insecticides before spring growth suppressed D. citri for five to six months, with no detectible impact on key natural enemies. This tactic has been widely adopted to control the psyllid in Florida, in some cases area-wide. Additional sprays during the growing season should be based on scouting and targeted at adults before anticipated new flush.  相似文献   

19.
There are currently no herbicides registered in Argentina for the selective control of grassy weeds in annual canarygrass (Phalaris canariensis L.). The principal grassy weeds are darnel ryegrass (Lolium temulentum L.) and wild oats (Avena fatua L.), which cause grain yield and quality losses. The potential of diclofop-methyl and clordinafop-propargyl for their control was assessed through greenhouse and field trials, in which crop phytotoxicity and weed control efficacy were evaluated. It was found that (i) field application of clordinafop-propargyl resulted in severe crop damage, except for low doses that did not affect the species to be controlled; (ii) although field application of diclofop-methyl resulted in a certain degree of phytotoxicity on wild oats, these effects were insufficient for efficacious control; and (iii) field and greenhouse application of diclofop-methyl between 200 and 500 g a.i. ha−1 revealed differences between crop sensitivity and that of darnel ryegrass. In this range, crop phytotoxicity in the greenhouse was less than 20% compared to more than 60% in the weed, and in the field only slight crop phytotoxicity symptoms were observed. As in the greenhouse, field application resulted in significant phytotoxic effects upon darnel ryegrass, high efficacy levels, a low survival rate amongst treated plants and a notable reduction in seed production by surviving plants. Only the highest dose (500 g a.i. ha−1) in one of the field trials resulted in a significant reduction in crop grain yield. Hence diclofop-methyl application appears to offer a promising means for controlling darnel ryegrass.  相似文献   

20.
Six insecticides were evaluated in a replicated field experiment at Gonzales, California, for control of the potato tuberworm,Phthorimaea operculella (Zeller), and the green peach aphid,Myzus persicae (Sulzer). Azodrin®, methomyl, Stauffer N 4543 (O-isobutyl ethylphosphonodithioate S-ester with N-(mercaptomethyl) phthalimide) and azinphosmethyl were applied as foliage sprays by ground sprayer at 2-week intervals. The systemic insecticides, aldicarb (Temik®) and carbofuran (Furadan®) formulated as 10% granules, were applied to the soil as side dress treatments on the same day that the spray treatments were begun. Aldicarb granules were also applied topically so that the granules fell on the young plants and on the soil surface. Azinphosmethyl, Stauffer N 4543, Azodrin® and methomyl effectively controlled the tuberworm larvae in the foliage but effective control of tuberworms in the harvested tubers occurred only where azinphosmethyl, methomyl and Stauffer N 4543 were used. The granule applications of carbofuran and aldicarb were totally ineffective in controlling the potato tuberworm. Effective green peach aphid control was obtained with Azodrin® spray and the two granular aldicarb treatments. The side dressed application of aldicarb appeared to provide better green peach aphid control than did the soil surface application.  相似文献   

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