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1.
In 3 year field experiments on pest and disease control by mobile overhead spraying of intensive Cox's Orange Pippin apple trees, overhead booms applying 1125 litres/ha and overhead mist-blowing equipment applying 562 litres/ha, each spraying two complete rows from one alley in half the normal time, were compared with conventional automatic mast spraying at 2250 litres/ha and with conventional mist-blowing at 562 litres/ha. The overhead boom application of demeton-S-methyl (0.0036% a.i.) with azinphos-methyl (0.0165% a.i.) or of fenitrothion (0.031% a.i.) at the green cluster stage gave control of the applegrass aphid, Rhopalosiphum insertum, virtually equal to that obtained by conventional application of the same insecticides. Similarly, the overhead mist applications of conventional quantities of insecticides gave equal control, but not when applying one-quarter of the normal amount of insecticides. The conventional methods generally gave better control of apple sucker, Psylla mali. In 1971, when the incidence of apple scab, Venturia inaequalis, was only moderate, the overhead boom method gave equal control to conventional spraying with both dodine/captan (0.03% a.i. and 0.094% a.i.) and benomyl (0.025% a.i.) programmes: in 1972 and 1973, when the scab incidence was heavier, the overhead boom spraying was again equal to the conventional method with the benomyl programme but was less effective with the dodine/captan programme. The overhead mist applications gave control only when the scab incidence was light. Repeated applications of dinocap emulsion (0.025% a.i.), included in the fungicide programme in 1971, gave as good control of the active stages of fruit tree red spider mite, Panonychus ulmi, when applied by the overhead methods as by conventional spraying, but application of the benomyl programme gave poor control. Mobile overhead spraying of small intensive apple trees is a promising method but needs further development before becoming fully acceptable.  相似文献   

2.
Abstract

A field experiment was conducted in 1973 and 1974 at Udaipur, India to evaluate the selective weed control efficacy of stale seed-bed prepared with paraquat (1 kg/ha) or by cultivation, pre-planting incorporation of EPTC (1.5 kg/ha), and post-emergent application of MCPB (0.5 kg/ha). Two crop protectants, NA and activated carbon, were also field tested as seed treatments against injury by EPTC. It was found that stale seed-bed prepared by desiccation of weed seedlings with paraquat a day before planting berseem (Trifolium alexandrinum L.) and pre-planting incorporation of EPTC were both effective in significantly reducing weed growth and boosting yields of berseem. Berseem seeds coated with activated carbon before planting provided appreciable protection to the crop against EPTC, but NA stunted berseem growth. A combination of stale seed-bed and EPTC caused maximum reduction in weed growth. Post-emergent MCPB, though efficient in controlling weeds, was highly phytotoxic to the crop. Chenopodium spp. and Phalaris minor were lower in net energy content than berseem.  相似文献   

3.
The effects of six herbicides on weed control, yield and quality of transplanted.‘Early Long Purple’eggplant (Solantam melongena L.,) were evaluated in two replicated field experiments during the wet seasons (June to December) of 1976 and 1977 on River Estate loam soil in trifluralin 0 kg and had gave the best yield and excellent weed control for 8 weeks. Benfluralin (kg and ha) isopropalin (1.5 kg m.a ha) and diphenamid (5.0 kg and ha) gave acceptable weed control for 8 weeks and satisfactory yields, but chlorthal-dimethyl (1 kg a ha) and hotra (40 kg a ha) were less satisfactory. All the herbicides tested controlled weed for 4 weeks. There was no crop injury. Effet des herbicides sur le desherbage de sendement et la qualite de l'aubergine (Solanum melongena L.,) d Trinidad Les effets de herbicides sur le desherbage, le rendement et la qualite de preds transplantes d'aubergine (Solantum melongena L.,) var ‘Farly Long Purple’, ont ete evalues dans deux experiences au champ, durant les sarsons humides (june to December repetees en 1976 et 1977, sur un sol argileux de River Estate a Trinidad La triflurraline 1.0 kg m a has donne le meilleut rendement et un excellent desherbage pendant S sernames I a benfluraline (1.1 kg m.a. ha) l'isopropaline (1.5kg ma. Ha) et le diphenamide (5.0 kg m.a ba) ont donne un desherbage acceptable et des rendements satisfaisant mais le chlorthal dimethyl (10.0 kg m.a ha) et la butraline (4.0 kg m.a ha) ont ete moins satisfaisants Tous les herbicides essayes ont maitrise les measures herbes pendant 4 semaines II n'y a pas eu de degats sur la recolte. Emsatz von Herbizalen in Eterfruchen Solanum melongena in Trinidad Wirkane aut Unkraut. Ertrag und Qualdat. Es wurde die Ergnung von wchs Herniziden fur die Unkraut-bekämpfung in gepfltanzten Eterfrüchten (Solaman melongena L.) der Sorte ‘Early Long Purple’ sowie the Wirkung aut Ertrag und Qualität in zwer Feldversuchen wahrend der Regen zen (Juni bis December) in den Jahren 1976 und 1977 auf einem River-Estate-Lehmnoden in Trinidad gepruit. Mit Trifluralin (1.0 kg ha AS) wurden die hochsten Ertage und cine ausgezetchnete Unkrauthekämpfung über acht Wechen erzielt Benfluralin (1.1 kh ha AS) Isopropalin (1.5 kg ha AS) und Dephenamid (5.0 kg ha AS) wirkten uber acht Wochen zufriedenstellend und führlen zu mittleren Ertagen; Chlorthaldimethyl (10.0 kg ha AS) und Butralin (4.0 kg ha AS) befriedigten weniger. Alle gepruften Herbicide bekämpften die Unkrauter uber cine Zeit von 4 Wochen. Schaden an der Kulturpflanze konnten nicht festgestellt werden.  相似文献   

4.
Defoliating caterpillars from the family Noctuidae are the most destructive insect pests on spearmint crop in Morocco. To control these pests, the growers apply several applications of non‐selective insecticides that are sometimes not registered for this use. This study investigates the efficacy of a set of selective chemical insecticides and other insecticides registered for organic farming against the defoliating caterpillars for better protection and in order to limit pesticide residues. Two insecticides authorized in organic farming and four other chemical insecticides were tested against the defoliating caterpillars under field conditions, following the randomized complete block experimental design with three replications. The comparative study of the efficacy of the different insecticides tested showed an average caterpillar reduction of 89.4, 82.5 and 68.1% with a defoliation reduction of 57.1, 53.8 and 43.9% for two of the tested synthetic insecticides, chlorantraniliprole (15cc/hl), emamectin benzoate (250g/ha) and for one of the tested bio‐insecticides, spinosad (30cc/hl) respectively. An increase of the total fresh mint weight compared to the non‐treated control was recorded for these three insecticides with 50.9%, 48.4%, and 40.5% for emamectin benzoate, chlorantraniliprole, and spinosad respectively. Insecticides containing chlorantraniliprole, emamectin benzoate, or spinosad active substances could be used as alternatives to other synthetic broad‐spectrum insecticides commonly used on spearmint in Morocco.  相似文献   

5.
Abstract

An experiment was designed to test the efficacy of various insecticides for the control of mustard aphid (Lipaphis erysimi (Kalt)) on mustard (Brassica juncea), variety RL 18 at the Research Farm of the Haryana Agricultural University, Hissar (India). Out of the 13 insecticides tried, each at two levels, it was found that methyldemeton 250 ml and menazon 250 g a.i. gave the maximum control of mustard aphid. Maximum yield of 1111 kg/ha was obtained with methyldemeton 250 ml (a.i./ha) against 360 kg/ha of the control.  相似文献   

6.
Abstract

The development of resistance to insecticides and the hazards inherent in their use present ever-increasing problems in insect control today. The difficulties and dangers have given impetus to research on other means of combating pests. Australia has always been prominent in the field of biological control, and the CSIRO Division of Entomology is an important centre, keenly seeking controls for both insects and weeds. Progress in the search for and establishment of parasites of Sirex, the pine pest, was described in Rural Research 64. This article reviews six other projects of particular interest, namely those involving potato moth, buffalo fly, white wax scale, green vegetable bug, lantana, and skeleton-weed.  相似文献   

7.
Action thresholds as decision tools for insecticide application were developed and tested against the major insect pests of rice at four sites in the Philippines over a 13-year period. Action threshold treatments were compared to the farmers' practice, prophylactic insecticide usage, and an untreated check. Yield loss data using the insecticide check method partitioned yield losses over three crop growth stages in the same test fields. Chronic pests that exceeded action thresholds in 79% of fields were whorl maggot Hydrellia philippina Ferino (Diptera: Ephydridae), defoliators Naranga aenescens Moore and Rivula atimeta (Swinhoe) (Lepidoptera: Noctuidae), leaffolders Cnaphalocrocis medinalis (Guenée) and Marasmia patnalis Bradley (Lepidoptera: Pyralidae), and stemborers Scirpophaga incertulas (Walker) and S. innotata (Walker) (Lepidoptera: Pyralidae). Minor chronic pests reached threshold levels in only one site each: rice bug Leptocorisa oratorius (F.) (Koronadal), whitebacked planthopper Sogatella furcifera (Horvath) (Zaragoza) and green leafhopper Nephotettix virescens (Distant) (Guimba); brown planthopper Nilaparvata lugens (Stål) did not exceed a threshold in any field. Stemborers were the most important pest group in terms of yield loss. Despite the insecticide check method underestimating losses, a mean crop loss of 0.62 t/ha was measured which showed ample scope for corrective action. But loss was evenly distributed across crop growth stages (0.15?–?0.24 t/ha) reducing the impact of insecticides. Action threshold treatments overall outyielded the untreated check, more so in the two sites with highest pest density. The benefit of thresholds was to reduce insecticide usage, as a cost saving. However all the practices showed poor economic returns including the farmers' practice. Farmers' practice employed low insecticide dosages and timing was not consistent with pest damage, but yields were often similar to threshold treatments. Farmers appear to use insecticide more for risk aversion than for profit. The best threshold characters when evaluated against resulting pest density and yield loss criteria showed accuracies >?90% correct decisions. Future work is needed to improve the insecticide response rather than monitoring tools. Thresholds need to be incorporated into improved crop management, which was often found suboptimal by farmers, to take advantage of the high levels of tolerance in modern high tillering cultivars. Crop husbandry practices which improve yield potential such as selection of longer maturing varieties and nitrogen fertilizer may be a more effective pest management strategy than insecticides.  相似文献   

8.
Five herbicides were tested in the dry and in the wet season for their effectiveness in conlrolling perennial nutsedge (Cyperus rotundus L.) in direct-seeded upland rice in the tropics. K-223 [N-(α,α-dimethylbenzyl)-N'-P-tolyl urea] gave the best results. When broadcast sprayed at 8.0 kg a.i./ha in the dry season and 10 kg a.i./ha in the wet season and immediately mixed into the soit just before drilling, K-223 gave excellent perennial nutsedge control with no visible crop damage and increased the grain yield. Bentazone at 2.0 kg a.i./ha applied 7 days after crop emergence was highly selective and gave fair control of nutsedge without being toxic to the crop. MBR 8251 [1.1,1-trifluoro-4′-(phenylsulfonyl) methane-sulfono-o-toluidide] at 2.0 kg a.i./ha, mecoprop (MCPP) at 1.5 kg a.c./ha and fenoprop (silvex) at 1.0 kg a.e./ha applied 7, 14 and 7 days, respectively after crop emergence provided a fair degree of nutsedge control. Fenoprop and MBR 8251 caused slight and mecoprop moderate initial toxicity, but the injury sustained did not significantly affect crop yield.  相似文献   

9.
Abstract

Flower shedding in summer mungbean, Vigna radiata (L.) Wilczek, is a common feature caused by thrips, Megalurothrips distalis (Karny). Eleven insecticides were tested in field trials for the control of thrips during the period 1982 to 1984. All the treatments were significantly better in controlling the thrips, reducing flower shedding, increasing the pod numbers and grain yield, in comparison with the control. Increases in yield compared with the control during trials ranged from 85 to 89% (1982), 26 to 96% (1983) and 5 to 194% (1984). Dimethoate gave the highest increases in yield and profit followed by monocrotophos and endosulfan.  相似文献   

10.
Abstract

Leek (Allium porrum L.) is an Important field vegetable in most of western and central Europe. Infestations of onion thrips (Thrips tabaci Lindeman) cannot be controlled with the range of insecticides now available in The Netherlands. Leek rust (Puccinia allii Rudolph) is now also difficult to control. Experiments in which no insecticides or fungicides were applied, were carried out to assess the effects on thrips populations and infection by leek rust when leek crops were undersown with subterranean clover (Trifolium subterraneum L.). To evaluate the economic aspects of this approach, both the quality and quantity of the leeks produced in the two systems were compared. Undersowing leeks with clover drastically reduced thrips infestations which was reflected in improved quality of leeks at harvest. Leek rust incidence was also reduced slightly by undersowing with clover and the quality of the leeks at harvest was also better. Although the quality of the leeks was improved when the crop was undersown with clover, the quantity of crop produced was reduced considerably as a result of plant competition.  相似文献   

11.
BACKGROUND: Cashew (Anacardium occidentale L.) has become a very important non‐traditional tree crop in Ghana. The crop is, however, attacked by sap‐sucking insects, particularly the mosquito bug, Helopeltis schoutedeni Reuter, the leaf‐footed bug, Pseudotheraptus devastans (Dist.), and the coreid bug, Anoplocnemis curvipes (F.), which feed on shoots, panicles and fruits. Their damage is characterised by withering of the latter. In Ghana, Oecophylla longinoda Latr. occurs in large numbers on cashew and other native plants, but little is known about its relationship with insect pests. The relationship between O. longinoda and shoot and panicle damage by sap‐sucking bugs and the effectiveness of O. longinoda as a biocontrol agent in the protection of cashew as compared with two chemical insecticides, lambda‐cyhalothrin (Karate®) and cypermethrin + dimethoate (Cyperdim®), were therefore investigated at Bole in the northern region of Ghana. RESULTS: There was a negative correlation between numbers of O. longinoda nests and pest damage. Trees treated with cypermethrin + dimethoate (969 mg AI mL?1 tree?1) and lambda‐cyhalothrin (100 mg AI mL?1 tree?1) recorded the smallest bug numbers, followed by O. longinoda. Trees infested by Oecophylla longinoda and trees treated with cypermethrin + dimethoate and with lambda‐cyhalothrin had less than 6% pest damage to shoots, panicles and fruits, while water‐sprayed trees recorded damage as high as 36.8% (shoots) in February, 32.9% (panicles) in February and 37.8% (fruits) in March. Cypermethrin + dimethoate again recorded the highest (485.0 kg ha?1) nut yield, followed by O. longinoda (431.0 kg ha?1), with water recording the lowest (93.0 kg ha?1) nut yield. CONCLUSION: The results indicate that O. longinoda can be used to control some sucking bugs as effectively as some insecticides. Copyright © 2008 Society of Chemical Industry  相似文献   

12.
Abstract

During and after sowing of groundnuts, dust, granule and emulsion formulations of some insecticides were tried against grubs of Lachnosterna (Holotrichia) consanguinea Blanch. attacking the crop. On the basis of percentage mortality of plants due to the grubs, phorate granules at 3 kg/ha were found most effective when applied both during and after sowing. Heptachior and Thiodemeton granules at 5 kg/ha were second in merit. Post-sowing treatments with dusts and emulsions were not very effective.  相似文献   

13.
The recent resurgence of the common bed bug, Cimex lectularius L., has driven an increase in research into the biology and behaviour of this pest. Current control is reliant on the application of insecticides, but, owing to the development of insecticide resistance, there is a need for new tools and techniques. Semiochemicals (behaviour‐ and physiology‐modifying chemicals) could be exploited for management of bed bugs. The aim of this review was to evaluate studies undertaken in bed bug chemical ecology to date, with particular reference to how the research could be exploited for monitoring and control. Bed bugs, like many other insects, have a complex olfactory system. Recent studies have characterised the olfactory sensilla, located on the terminal segment of the antennae, to functional classes by electrophysiological screening. Behavioural studies have revealed the presence of an alarm pheromone and potential airborne aggregation semiochemicals, but it is not yet understood if bed bugs use a sex pheromone during mating. Host location cues have been investigated, and carbon dioxide has been found to be highly attractive both in laboratory and in field studies. Recent field trials have tested blends of other potential kairomones, which have been shown to have an additive effect when used in a heated bed bug trap with carbon dioxide. The trap, which combines heat and kairomones, is the only trap currently available with proven efficacy in the field. In order for semiochemicals to be useful for bed bug management, an increased knowledge and understanding of the biology, behaviour and chemical ecology of this insect is essential. Copyright © 2010 Society of Chemical Industry  相似文献   

14.
The resistance of Cydia pomonella (L.) to organophosphates is widespread throughout the pome fruit growing areas. The lethal effects of two insecticides inhibitors of the acetylcholine esterase, azinphos-methyl and carbaryl, were evaluated in adults of five and four field populations of the codling moth, respectively. The lethal concentrations (LC50 and LC90) of these insecticides were determined in a susceptible strain from Spain (S_Spain). Topical bioassays using the approximate LC90 values (3000 mg (a.i.)/L of carbaryl and 2000 mg (a.i.)/L of azinphos-methyl) that were obtained in S_Spain were tested as diagnostic concentrations. The enzymatic activities of mixed-function oxidases (MFO), glutathione S-transferases (GST) and esterases (EST) were measured to investigate their potential role in the detoxification of these insecticides.Carbaryl and azinphos-methyl caused ?53% and ?39% corrected mortality, respectively, in field populations, although the diagnostic concentrations applied were twofold and fourfold higher than the maximum concentration registered in Spain, respectively. The activities of MFO and GST were 7.3- to 16.1-fold higher and 2.5- to 3.7-fold higher in all the field populations compared to those in S_Spain, respectively.  相似文献   

15.
D. HAWTON 《Weed Research》1980,20(1):33-40
In field experments on the Altherton Tableland. Queensland. Auslralia, methabenzthiazuron used at 1 2 kg ha pre-emergence was the most effective herbicide for selectively controlling Eleusine indica (L.) Gaertn in seed crops of Setaria anceps Stapf. Bromoxynil. bromoxynil plus MCPA, simazine and terbutryne were either ineffective or phytotoxic to S anceps. A more reliable technique was the use of diuron applied at 2.8 kg ha pre-emergence when the crop row was physically protected with metal shields at spraying or when activated carbon applied as a slurry in water at 168 kg per sprayed ha was sprayed in a 3 cm wide band over the crop row at sowing Three successive applications of paraquat over a 39 day period prior to sowing the crop were necessary for effective control of E. indica using the ‘stale seed bed’ technique  相似文献   

16.
Summary. Paraquat-based treatments were evaluated for the control of Imperata cylindrica (L.) Beauv., a perennial grass with extensive rhizomes of great regenerative power. Single applications of 0–5 lb/ac paraquat gave good initial control, but regeneration was rapid. Increases up to 2–0 lb/ac had little effect on the duration of control, nor did the volume rate from 40 to 120 gal/ac. When an initial application of 05 lb/ac was followed by two further applications of 0–25 lb/ac, when the level of control had decreased to 50%, lasting control was obtained. Application of 6–8 lb/ac dalapon followed by 0–25 lb/ac paraquat also gave good control, comparable with that achieved by the conventional treatment of dalapon alone at 15–20 lb/ac. La lutte chimique contre Imperata cylindrica (L.) Beauv. en Malaisie Résumé. Des traitements utilisant le paraquat ont étè essayés pour lutter contre Imperata cylindrica (L.) Beauv., graminée pérenne avec des rhizomes importants qui manifestent un pouvoir de régénération élevé, Des applications uniques de paraquat à la dose 0,56 kg/ha ement un bon eifel initial mais la régéneration fut rapide. L'accroissement de la dose jusquà 2,2 kg/ha n'eut qu'une faible incidence sur la durée de l'action herbicide, l'augmentation du volume de traitement de 450 à 1350 1/ha ne provoqua pas non plus d'augmentation de I'efficacité. Une seule application de paraquat à 0,56 kg/ha, quand le niveau de I'efficacité eut décru jusquà 50%, suivie de deux applications supplémen-taires à 0,275 kg/ha, donna une efficacité plus durable. Des applications de dalapon de 6,7 à 9,0 kg/ha suivies de traitements au paraquat à 0,275 kg/ha donnèerent un résultat aussi bon que celui obtenu par les traitements habituels au dalapon seul, à la dose dc 16 à 22 kg/ha. Chemisehe Bekampfung von Imperata cylindrica (L.) Beauv. in Malaysia Zusammenfassung. Es erfolgten Untersuchungen zur Bekämpfung von Imperata cylindrica (L.) Beauv., einem mehrjährigen Gras mit einem ausgedehnten Rhizomsystem und starker Regenerationskraft, mit Paraquat, Einmalige Applikation von 0,56 kg/ha Paraquat hatte zwar eine gute Anfangswirkung, doch erfolgte rasche Regeneration. Eine Erhöhung bis auf 2,2 kg/ha war ebenso wie eine Änderung der Spritzbrühmenge von ca 450–1350 I/ha von geringem Einfluss auf die Nachhaltigkeit der Bekämpfungs-massnahmen. Eine einmalige Anwendung von 0,56 kg/ha Paraquat gefolgt von zwei weiteren Applikationen von 0,28 kg/ha, wenn die Regeneration ungelahr 50% erreicht hatte, ergab nachhaltige Wirkung. Behandlungen mit 6,7-9 kg/ha Dalapon gefolgt von 0,28 kg/ha Paraquat hatten ebenfalis eine gute Wirkung, die mit der einer konven-tionellen Behandlung mit 16,8-22 kg/ha Dalapon vergleiehbar war.  相似文献   

17.
Abstract

Bio‐efficacy of 15 insecticides was evaluated against the pest complex of okra in the semi‐arid region of Rajasthan during July‐October, 1984. Five sprays given at intervals of 15 days throughout the crop period indicated that fenvalerate (0.02%) was most effective, followed by permethrin (0.02%), cypermethrin (0.02%), carbaryl (0.10%), monocrotophos (0.04%) and dimethoate (0.03%), against leafhoppers, aphids and fruit borer. The maximm yield of marketable fruits was obtained with fenvalerate, followed by cypermethrin, carbaryl, monocrotophos and dimethoate treatments. Highest net‐profit of Rs. 4890.00 was also recorded with fenvalerate treatment, followed by Rs. 4430.00 with carbaryl, Rs. 4148.00 with permethrin, Rs. 3977.00 with monocrotophos and Rs. 3053.00 with dimethoate treatments. A higher benfit cost ratio was found with carbaryl (1:9.78), followed by dimethoate (1:7.85), monocrotophos (1:5.18), methyl demeton (1:5.07), fenvalerate (1:3.43) and permethrin (1:2.41). These insecticides can also be used against insect pests of other vegetable crops of the season.  相似文献   

18.
The prolonged use of dimethoate, introduced into Denmark to control houseflies (Musca domestica L.) that had become resistant to parathion and diazinon, resulted ultimately in dimethoate resistance. Selection with dimethoate led to the disappearance of the hydrolytic phosphatase, a major mechanism of resistance to parathion and diazinon, and its replacement by the acetylcholinesterase AChER with somewhat decreased sensitivity to inhibition by organophosphorus (OP) insecticides. The hydrolytic phosphatase probably disappeared because low substrate turn-over made it ineffective against dimethoxon (O, O-dimethyl S-methylcarbamoylmethyl phosphorothioate, also known as omethoate). which accumulates at higher concentrations than paraoxon (diethyl4-nitrophenyl phosphate) in the haemolymph. Dimethoate selected AChER preferentially because it improved the chances of houseflies surviving against the relatively poor AChE inhibitor dimethoxon, whereas its relatively small insensitivity to OP insecticides, unimportant against good inhibitors such as paraoxon, prevented its selection by parathion.  相似文献   

19.

Background

Cimex lectularius L. (bed bug) (Hemiptera: Cimicidae) is a serious indoor pest worldwide, and this nuisance needs to be controlled using different methods in integrated pest management (IPM). Beauveria bassiana (Bals.-Criv.) Vuill. (Hypocreales: Cordycipitaceae) kills bed bugs, and insect pathogenic fungi may be utilized to control bed bugs in IPM. To increase knowledge of this methodology, forced exposure experiments were conducted with different formulations, doses, and substrates, using bed bugs in variable physiological states.

Results

Both oil- and water-formulated fungal products showed significant improvement when conidial concentrations were raised in five steps from 0.02 to 2.0%. At low concentrations (0.02% in water) effects from substrate and application strategy were observed. Application on soft substrates (cotton and polyester) yielded significantly higher bed bug mortality rates than on harder substrates (paper, wood, and linoleum) with a final mortality of 35–63% against 8–10%. Multiple applications over time also improved B. bassiana's ability to kill bed bugs, and at low concentrations only a triple application on cotton showed 100% final mortality. Bed bug age and reproductive status significantly affected survival. Older and reproducing individuals showed higher mortality compared to newly emerged adults. Differences in feeding status also yielded differences in mortality timing, but only minor differences in final mortality rates. Egg production and hatching success were significantly reduced by some treatments.

Conclusion

B. bassiana appears to be an asset in the fight against bed bugs. Substrate, dosage, application strategy, and bed bug physiology are important factors to consider for optimal efficacy and safe indoor control with insect pathogenic fungi. © 2023 Society of Chemical Industry.  相似文献   

20.
Field experiments were conducted from 1989 to 1992 to determine the effects of pre-emergence herbicides in sunflower (Helianthus armuus L.) on: (1) the control of Orobanche cemua Loefl. (broomrape) and (2) crop damage and crop yield. Herbicides tested belong to the imidazolinone, sulfonylurea and substituted amide families. Imazethapy r (20–40 g ha?1), imazapy r (12.5–25 gha?1) and chlorsulfuron (4–6 gha?1) controlled broomrape efficiently without crop injury. With good O. cernua control and good crop tolerance, sunflower seed yield from these treatments were generally similar to the non-infested checks and higher than the infestedchecks. Imazaquin (20–40 gha?1), triasulfuron(4gha?1), pdmisulfuron(3g ha?1), acetochlor (4–4 kg ha?1) and metazachlor (2 kg ha?1) were less effective. Imazamethabenz (200–600 g ha?1) and metolachlor (3–3 kg ha?1) were ineffective. Wetconditions aftercropsowing considerably decreased O. cemua control with pre-emergence herbicides probably caused by enhanced degrädation. Des herbicides de prelevee pour la lutte contre Vorobanche (Orobanche cemua Loefl.) dans le toumesol (Helianthus annuus L.) Des expérimentations au champ ont été conduites de 1989 á 1992 pour determiner les effets d'herbicides de pré1evée du toumesol sun (a) la destruction de l'orobanche (Orobanche cernua Loefl.) et (b) la phytotoxcité sur la culture. Les herbicides testés appartenaient aux imidazolinones, aux sulfonylurdes et aux amides substituées. L'imazethapyr (20 á 40 gha?1), l'imazapyr (12,5 á25gha?1)et le chlorsulfuron (4 á 6 gha?1) détruisaient efficacement l'orobanche sans occasionner de phytotoxidt6 sur la culture. Dans ces conditions, les rendements étaient généralement semblables à ceux des témoins non infestés et supérieurs à ceux des témoins infestés. L'imazaquin (20 à 40 g ha?1), le triasulfuron (4 gha?1), le primisulfuron (3 g ha?1), lacétolachlor (4,4 kg ha?1) et le métazachlor (2 kg ha?1) étaient moins efficaces. L'imazaméthabenz (200 á 600 g ha?1) et le métolachlor (3,3 kg ha?1) etaient inefficaces. Des conditions humides aprfes le semis diminuaient considérablement la destruction de O. cemua par les herbicides de prélevée, probablement à cause d'une dégradation plus élevée. Vorauflaufherbigide zur Bekdmpfung der Sommerwurz Orobanche cemua Loefl. in Sonnenblume (Helianthus annuus L.) Zwischen 1989 und 1992 wurden in Sonnenblume Feldversuche zur Wirkung von Vorauflaufherbiziden aus den Gruppen der Imidazolinone, Sulfonylharnstoffe und substitutierten Amide auf die Sommerwurz Orobanche cernua und auf Kulturpflanzenschaden sowie den Ertrag durchgefuhrt. Mit Imazethapyr (20 bis 40 g ha?1), Imazapyr (12,5 bis 25 g ha?1) und Chlorsulfuron (4 bis 6 g ha?1) lieβ sich die Sommerwurz wirksam bekampfen, ohne daβ Schaden an der Sonnenblume auftraten, und die Ertrage waren allgemein ahnlich oder hoher als bei der nichtparasitierten Kontrolle. Imazaquin (20 bis 40 ha?1), Triasulfuron (4 g ha?1).Primisulfuron (3 g ha ?1). Acetochlor (4,4 kg ha ?1 und Metazachlor (2 kg ha ?1) waren weniger wirksam. Imazamethabenz (200 bis 600 g ha?1) und Metolachlor (3,3 kg ha?1) hatten keine Wirkung. Bei Niederschlagen nach der Saat der Sonnenblume war die Bekampfung der Sommerwurz mit Vorauflaufherbiziden vermutlich wegen verstärkten Abbaus erheblich schwächer.  相似文献   

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