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1.
The insecticidal activities of four surfactants (Cide‐kick, Silwet L‐77, M‐Pede and APSA‐80), a dishwashing detergent (New Day), a mineral oil (Sunspray oil), a cotton seed oil and a vegetable oil, alone or in combination, were tested against nymphs of Bemisia argentifolii Bellows & Perring on collards and tomato. Silwet L‐77 was more effective (>95% mortality) than Cide‐Kick or APSA‐80 at rates from 0.25–1.00 g AI litre−1 but caused severe phytotoxicity to tender tomato leaves at all but the lowest rate. New Day dish detergent at 2.0 ml litre−1 caused mortality (95%) comparable to M‐Pede insecticide soap at 10‐fold greater concentration. A New Day ingredient, cocamide DEA, was considerably more active than the other ingredients or the commercial mixture. Additional surfactants added to Sunspray oil increased efficacy in some treatments, but not others. Toxic responses of 2nd‐ and 3rd‐ instar whiteflies to vegetable oil and cotton seed oil at 5.0 and 10.0 ml litre−1 plus 0.4 g AI litre−1 APSA‐80 ranged from 22.1 to 79.9% and 66.3–88.7% mortality, respectively. Whitefly mortality was greater on tomato than on collard in six of seven instances when differences between host plants were significant. Our results indicate that the these surfactants and oils have good potential for controlling B argentifolii. © 2000 Society of Chemical Industry  相似文献   

2.
The response of Cuscuta campestris Yuncker, a non‐specific above‐ground holoparasite, to amino acid biosynthesis inhibitor (AABI) herbicides, was compared with other resistant and sensitive plants in dose–response assays carried out in Petri dishes. Cuscuta campestris was found to be much more resistant to all AABI herbicides tested. The I50 value of C. campestris growth inhibition by glyphosate was eightfold higher than that of transgenic, glyphosate‐resistant cotton (RR‐cotton). The I50 value for C. campestris shoot growth inhibition by sulfometuron was above 500 μM, whereas that of sorghum roots was only 0.004 μM. Cuscuta campestris exposed to glyphosate gradually accumulated shikimate, confirming herbicide penetration into the parasite and interaction with an active form of the target enzyme of the herbicide, 5‐enolpyruvylshikimate‐3‐phosphate synthase. More than half of the C. campestris plants associated with transgenic, glyphosate‐resistant sugarbeet (RR‐sugarbeet) treated with glyphosate or with transgenic, sulfometuron‐resistant tomato (SuR‐tomato) treated with sulfometuron recovered and resumed regular growth 20–30 days after treatment. New healthy stems developed, followed by normal flowering and seed setting. The results of the current study demonstrate the unique capacity of C. campestris to tolerate high rates of AABI. The mechanism of this phenomenon is yet to be elucidated.  相似文献   

3.
M N Shao  B Qu  B T Drew  C L Xiang  Q Miao  S H Luo 《Weed Research》2019,59(3):201-208
The establishment of invasive species is widely recognised as a pivotal issue in the preservation of biodiversity. Salvia reflexa, a species native to the south‐central United States and Mexico, has been widely introduced in Argentina, Australia, New Zealand and Japan. In China, the first population of this plant was found growing adjacent to a grain depot in Shahai village, Jianping County, Liaoning Province, on 25 July 2007. Since the grain depot imported foodstuffs from regions where the plant is native, we infer that S. reflexa was introduced into China via imported foodstuff in the early to mid‐2000s. Based on field observations, at least seven populations of this plant were observed in north‐east China. The plants displayed vigorous growth in midsummer and produced prolific seeds to overcome the cold environment in winter. Salvia reflexa occurred in both dense monocultures and in mixed stands with native plants. In order to validate a system for recognising and categorising non‐native plants in China, the Australian Weed Risk Assessment system was used to assess the invasiveness status of 19 exotic and 16 native plants in north‐east China. Salvia reflexa exhibited a high score of 10, suggesting it is a potentially pernicious alien invasive plant. Although the current distribution of S. reflexa is restricted to Liaoning province and thus far has limited impact on local environments, local regulatory authorities should pay close attention to this plant and take measures to stop its expansion. This is the first time that an invasive plant from the Lamiaceae (mint family) has been documented from cold environments in China.  相似文献   

4.
Spotted lanternfly (SLF), Lycorma delicatula (Hemiptera: Fulgoridae) is an invasive phloem‐feeding planthopper currently being quarantined in a 24 000 km2 area in eastern Pennsylvania, New Jersey, Maryland, and Delaware, with a second population under quarantine in a 46 km2 area in Virginia. Because this insect feeds on over 70 species of plants, it has the potential to impact a wide range of sectors, and as a result, there has been great public speculation that the economic impact of SLF could be severe. SLF is a large‐bodied voracious feeder that reduces plant resources directly by feeding, and indirectly, from sooty mold that grows on its excrement and blocks photosynthesis. SLF is causing severe damage to vineyards from feeding, and is a significant nuisance pest. It has high potential for spread via human‐mediated transport, particularly of egg cases, and may therefore significantly impact commerce in the near future. The ultimate impacts of this insect are not yet known, and will depend upon its longer term impacts on plant and tree health, and the extent to which its range expands. © 2019 Society of Chemical Industry  相似文献   

5.
Resistance to the acetyl‐coenzyme A carboxylase (ACCase)‐inhibiting herbicides in Lolium rigidum is widespread in grain cropping areas of South Australia. To better understand the occurrence and spread of resistance to these herbicides and how it has changed with time, the carboxyl transferase (CT) domain of the ACCase gene from resistant L. rigidum plants, collected from both random surveys of the mid‐north of Southern Australia over 10 years as well as stratified surveys in individual fields, was sequenced and target site mutations characterised. Amino acid substitutions occurring as a consequence of these target site mutations, at seven positions in the ACCase gene previously correlated with herbicide resistance, were identified in c. 80% of resistant individuals, indicating target site mutation is a common mechanism of resistance in L. rigidum to this herbicide mode of action. Individuals containing multiple amino acid substitutions (two, and in two cases, three substitutions) were also found. Substitutions at position 2041 occurred at the highest frequency in all years of the large area survey, while substitutions at position 2078 were most common in the single farm analysis. This study has shown that target site mutations leading to amino acid substitutions in ACCase of L. rigidum are widespread across South Australia and that these mutations have likely evolved independently in different locations. The results indicate that seed movement, both within and between fields, may contribute to the spread of resistance in a single field. However, over a large area, the independent appearance and selection of target site mutations conferring resistance through herbicide use is the most important factor.  相似文献   

6.
麦套Bt棉田的经济效益和对棉蚜及天敌的影响   总被引:1,自引:0,他引:1       下载免费PDF全文
2004~2005年,在冀南棉区调查了麦套Bt棉田对棉花苗期蚜虫和天敌的影响及其经济效益。结果表明,麦套棉田的棉蚜数量均显著低于对照田(P<0.05),其高峰期的蚜虫种群数量低于防治指标,且受棉蚜的危害程度小于对照田。麦套棉田中的瓢虫和僵蚜的种群数量显著高于对照田和化防田,与对照田相比,麦套棉田中的瓢虫发生高峰期提前10天左右。化防田的籽棉产量高于麦套棉田和对照田,但麦套棉田2004和2005年的综合经济效益分别为1.7万元/hm2和2.08万元/hm2,比化防田多0.53万元/hm2和0.57万元/hm2。试验结果还表明,棉花苗期蚜虫能够显著影响棉花产量,采用套种等多熟种植模式可以作为Bt棉有害生物综合治理的重要组成部分。  相似文献   

7.
This study presents a list of invasive alien plants that are found along roadsides in seven selected European countries – Austria, Germany, the Netherlands, Ireland, Norway, Slovenia and Sweden – and an overview on the role of roadsides as a habitat for invasive alien plants. This compilation is based on national lists of invasive alien plants, a literature search and expert consultation. Comprising 89 species from 31 plant families, species introduced for horticulture dominate the list (65%). Thirteen species (14%) are widespread (occur in four or more countries) and include well‐known invasive plants such as Fallopia japonica, Heracleum mantegazzianum, Solidago canadensis and Solidago gigantea. Seventeen species are listed either on the EPPO List of Invasive Alien Plants or on the EPPO A2 List of pests recommended for regulation as quarantine pests. Five species are on the List of Invasive Alien Species of Union Concern (EU Regulation 1143/2014). The compiled list provides a snap‐shot of invasive alien plants currently found along roadsides in the selected countries. It allows for a more targeted approach to monitoring, containment and control of the most problematic invasive alien plants identified in each country. Moreover, the list may also be used to identify emerging (potentially) invasive alien plants along roadsides in other European countries that warrant monitoring and/or management.  相似文献   

8.
Compared with natural seed dispersal, human‐mediated seed dispersal could spread herbicide resistance genes on a much larger scale. Herbicide‐resistant weed seeds have been reported as contaminants in commercial grain. We investigated the contamination of seeds of Lolium species with target‐site mutations conferring resistance to acetolactate synthase (ALS)‐inhibiting herbicides in wheat imported from the USA, Canada and Australia into Japan. We also investigated the establishment of ALS‐inhibiting herbicide‐resistant Lolium species in 12 seaports in Japan that are major entry points for international commodities. We found herbicide‐resistant Lolium spp. seeds from all classes of wheat samples. Resistant individuals became established at six of eight ports where more than 50 kt of imported wheat is unloaded every year. The establishment of resistant Lolium spp. individuals was common at major grain landing ports. Monitoring over 3 years at one port revealed that the frequency of resistant individuals did not fluctuate between years. Many resistant individuals were distributed in front of the entrance of a fodder company, but a few resistant individuals were found in areas 2 km away from the port. The results indicate that gene flow is rare through pollen or seed movement from resistant plants to peripheral populations. Further extensive and long‐term monitoring is necessary to perform a comprehensive risk assessment of herbicide‐resistant plants entering Japan through major commercial ports.  相似文献   

9.
S W LAFFAN 《Weed Research》2006,46(3):194-206
Knowledge of the spatial distribution of weed infestations over regional scales is essential for effective management of source populations and to assess future threats. To this end, the distributions of Nassella trichotoma across a study area in south‐east New South Wales, Australia, were analysed using the geographically local Getis–Ord Gi* spatial hotspot clustering statistic. The clustering of N. trichotoma observations was analysed at three infestation levels: presence (at any density), patch level and the occasional plant level. The results indicate that there are c. 578 km2 of cells containing N. trichotoma in strongly clustered infestations, 11.2 km2 within weakly clustered infestations distinct from the main clusters, and 55 km2 that are not clustered. There are 117 km2 of strongly clustered patch level cells, 3 km2 in distinct but weak clusters, and none outside of a cluster area. Of the occasional plant level cells, 329 km2 are strongly clustered, 6.2 km2 are in distinct but weak clusters, and 19 km2 are not clustered. These results provide a mechanism by which control efforts can be prioritized. The analysis approach described in this paper provides a consistent, quantitative and repeatable approach to assess weed infestations across regional scales and can be applied to any weed species for which spatial distribution data are available.  相似文献   

10.
The indigenous Lachnagrostis filiformis colonized extensive areas of dry lake beds in Victoria, Australia, during the drought from 1997 to 2009. Large numbers of the plants' detached seed heads disperse in the wind, lodging against nearby housing, fences and other obstacles. This accumulation of material creates a fire hazard, degrades townships' aesthetics and presents a nuisance to the communities of lake‐side towns. This study aimed to examine the effects of various control methods on L. filiformis in the short and long term. Although herbicide applications, slashing, grazing and burning were found to be effective in controlling the blown L. filiformis seed heads in the short term, they failed to prevent subsequent reinvasion and can increase its abundance in the long term. The late application of herbicide resulted in an increase in the foliage cover and seed‐head biomass of L. filiformis by up to 37% and 150%, respectively, in the year following the treatment application. The results from this study highlight how management focused on achieving short‐term goals, without consideration of the successional trajectory after implementation, can not only fail but be counter‐productive in the long term. In order to achieve sustainable management, the fundamental ecological processes that promote the establishment and persistence of the weed need to be addressed.  相似文献   

11.
A rapid glasshouse‐based bioassay method to screen large numbers of cotton plants for responses to Fusarium oxysporum f. sp. vasinfectum (Fov) was developed. Different Fov inoculum concentrations and methods of inoculation were assessed using resistant and susceptible cotton cultivars. Cotton seeds were planted directly into Fov‐inoculated soil. Studies of seed germination, seedling establishment, seedling mortality and fusarium wilt symptoms (i.e. stunting, foliar symptoms and vascular browning) were performed to optimize the bioassay parameters. Growing seedlings in Fov‐inoculated soils at 5 × 104 or 1 × 105 CFU g?1 soil, in individual seedling tubes with 12 h at 28–30°C and 12 h at 15–18°C, gave consistent results when assessing Fov disease responses 6 weeks after inoculation. When fusarium wilt resistance ranks (FWRRs) and vascular browning index (VBI) means of 18 Australian and other cotton cultivars from the Fov glasshouse bioassay were compared against their fusarium field performance ranks (F‐ranks), assessed on adult plants for cotton cultivar release, Pearson’s correlation was highly significant for both comparisons. The level of congruence between field and glasshouse data indicated that this protocol should be an effective tool for large‐scale screening for Fov‐resistance responses in diverse germplasm and breeding populations and for advancing genetic research to develop molecular markers for Fov resistance in cotton.  相似文献   

12.
Fipronil seed treatments were evaluated to determine whether they directly influence germination and subsequent seedling growth in rice (Oryza sativa L). Continuous seed exposure to fipronil (four days) at 2 000 mg litre−1 significantly impaired germination (P < 0.001). When exposure was restricted to a 1-h period 48 h after the initiation of germination, early post-germination growth was also impaired (assessment two days after exposure, P < 0.05). The proportion of seeds satisfying our criteria for normal germination fell by 2.3 and 2.6% respectively across 17 cultivars. Cultivar effects were highly significant (P < 0.001). When exposure to fipronil (2 000 mg litre−1) was restricted to 2 h at initial seed wetting no significant growth impairment occurred. No significant differences (P > 0.05) were found between shoot lengths or root system dry weights of control plants and plants developing from seed exposed continuously (two days) to fipronil at rates of up to 2 000 mg litre−1 during germination and harvested nine days after sowing. Treating germinated seed with fipronil for 1 h immediately prior to sowing at rates of up to 4 000 mg litre−1 did not result in significant changes (P < 0.05) in plant growth parameters at either nine or 25 days after sowing. No evidence of fipronil having a direct phytostimulatory effect on rice was obtained. © 1999 Society of Chemical Industry  相似文献   

13.
Abstract

Sorghum halepense (L.) Pers. (Johnson grass) is an important weed in many countries. In Australia it invades crop lands, provides a harbour for diseases and insect pests of sorghum and maize, contaminates sorghum grown for seed and constitutes a safety hazard along roadsides.  相似文献   

14.
Common ragweed (Ambrosia artemisiifolia) is an invasive annual plant with highly allergenic pollen. Its spread in introduced and native ranges often occurs on roadsides, where it builds stable and rapidly growing populations. The most sustainable way of controlling the population size of this species is to prevent seed production in order to deplete the soil seed bank. Populations on roadsides are submitted to regular mowing management, which can even exacerbate the situation by inducing resprouting after cutting or by accidentally spreading seeds along the road. The population density in the juvenile stages of development could play an important role in the success of cutting regimes, as it might influence the resprouting capacity of this plant. The influence of the juvenile population density and of seven cutting regimes, differing in the timing and frequency of cuts, on easily measurable reproductive traits was investigated in a glasshouse experiment. The cutting regimes had a strong influence on the reproductive success and on the phenology of the development stages of ragweed. The population density in the juvenile stages did not play a role in further phenological development, but did influence the reproductive traits. The reproduction of ragweed can be lowered by locally adapted combinations of the timing and frequency of mowing. As the optimal management option for the reduction of both the male and female flowers, the authors suggest a first cut just before the start of male flowering, followed by subsequent cuts every 3–4 weeks.  相似文献   

15.
The Asiatic yellow‐spotted longicorn beetle, Psacothea hilaris hilaris, was found for the first time in Northern Italy in 2005. As this xylophagous insect is considered one of the most important pests of Morus spp. and of Ficus carica in its countries of origin, a multi‐year study was carried out to determine the spread of the pest in Northern Italy, to evaluate its establishment potential and to improve knowledge on its biology in the new habitat. The survey confirmed that P. hilaris hilaris has established in Italy and has colonized an area of about 60 km2. The species overwinters as eggs or larvae. Adults are present from June to October. Damage has been recorded mostly on Ficus carica plants, and very rarely on Morus alba. Both young and older plants, healthy and weakened hosts can be attacked by the pest. Severely attacked plants become weakened and eventually die.  相似文献   

16.
J. DODD 《Weed Research》1989,29(4):255-263
Production of viable seeds occurred in immature capitula of Silybum marianum following simulated slashing and mowing. In the slashing treatment, capitula with 20 cm or less of stem attached produced viable seeds if cut off when at least half the florets were open, the proportion of viable seeds ranging from 0·3% in capitula at midanthesis to 12% in those at the end of anthesis. Following mowing, viable seeds were produced in full-sized buds which were close to anthesis and in capitula at any stage of anthesis at the time of plant cutting, the proportion increasing from 0·1% in capitula at the start of anthesis to 30% in those at the end. Within a capitulum, anthesis usually lasted five days in irrigated plants. Ripe seeds were released about 17 days later. Seed production averaged 190 seeds for the primary capitulum and 114 in others. In a flowering season starting in early November and lasting about two months, individual plants had the potential to produce an average of 55 capitula, representing an output of 6350 seeds per plant, of which 94% were viable. In view of the prolonged flowering season and the large seed output of S. marianum, it is argued that the restricted period of oviposition by the weevil Rhinocyllus conicus and the low density of larvae per capitulum might limit its impact as a biological control agent for this weed in Australia.  相似文献   

17.
The study examined the effect of tillage (intensive vs. zero tillage) on potential gene flow during the life cycle of oilseed rape volunteers between July 2002 and August 2003. After growing oilseed rape, 4–29% of the seeds lost during harvest entered the soil seedbank when stubble tillage was performed immediately after the seed input. The seedbank was small (0–3%) when stubble tillage was delayed. Zero tillage resulted in seedbanks from 1 to 17% of the initial seed input. The seeds were distributed mainly in the upper soil layers after zero tillage or primary tillage with a rigid tine cultivator, whereas ploughing shifted most of the seeds into deeper layers. The highest number of volunteers (1 plant m−2) emerged and flowered in the following crop of winter wheat either when a large soil seedbank existed and/or the seedbank was located mainly in the upper soil layer. Outcrossing with other rape crops was unlikely as volunteers flowered 1 month later than rape crops sown at the normal timing. These volunteers produced a maximum of 8 viable seeds m−2. Ploughing preserved seeds in deep soil layers transferring the risk of gene flow to the future, whereas non-inversion tillage can cause gene flow from high numbers of flowering volunteers within the first year following oilseed rape cultivation.  相似文献   

18.

BACKGROUND

Bemisia tabaci is a globally significant agricultural pest including in Australia, where it exhibits resistance to numerous insecticides. With a recent label change, buprofezin (group 16), is now used for whitefly management in Australia. This study investigated resistance to pyriproxyfen (group 7C), spirotetramat (group 23) and buprofezin using bioassays and available molecular markers.

RESULTS

Bioassay and selection testing of B. tabaci populations detected resistance to pyriproxyfen with resistance ratios ranging from 4.1 to 56. Resistance to spirotetramat was detected using bioassay, selection testing and sequencing techniques. In populations collected from cotton, the A2083V mutation was detected in three populations of 85 tested, at frequencies ≤4.1%, whereas in limited surveillance of populations from an intensive horticultural region the frequency was ≥75.8%. The baseline susceptibility of B. tabaci to buprofezin was determined from populations tested from 2019 to 2020, in which LC50 values ranged from 0.61 to 10.75 mg L−1. From the bioassay data, a discriminating dose of 200 mg L−1 was developed. Recent surveillance of 16 populations detected no evidence of resistance with 100% mortality recorded at doses ≤32 mg L−1. A cross-resistance study found no conclusive evidence of resistance to buprofezin in populations with high resistance to pyriproxyfen or spirotetramat.

CONCLUSIONS

In Australian cotton, B. tabaci pest management is challenged by ongoing resistance to pyriproxyfen, while resistance to spirotetramat is an emerging issue. The addition of buprofezin provides a new mode-of-action for whitefly pest management, which will strengthen the existing insecticide resistance management strategy. © 2023 Commonwealth of Australia. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   

19.
As herbicide‐resistant weeds have spread in the agricultural fields of grain‐exporting countries, their seeds could be introduced into other countries as contaminants in imported grain. The spread of resistance genes through seed and pollen can cause significant economic loss. In order to assess the extent of the problem, we investigated the contamination by herbicide‐resistant annual ryegrass (Lolium rigidum) of wheat imported from Western Australia into Japan. Annual ryegrass seeds were recovered from wheat shipments and seed bioassays were conducted to identify resistance to the herbicides that are commonly used in Australia: diclofop‐methyl, sethoxydim, chlorsulfuron, and glyphosate. Nearly 4500 ryegrass seeds were detected in 20 kg of wheat that was imported in both 2006 and 2007. About 35% and 15% of the seeds were resistant to diclofop‐methyl, 5% and 6% were resistant to sethoxydim, and 56% and 60% were resistant to chlorsulfuron in 2006 and 2007, respectively. None was resistant to glyphosate in either year. As the contamination of crops by herbicide‐resistant weeds is probably a common phenomenon, the monitoring of incoming grain shipments is necessary to stem the further spread of herbicide‐resistant weeds into importing countries.  相似文献   

20.
不同施药方式下吡虫啉对棉田绿盲蝽种群动态的影响   总被引:4,自引:0,他引:4  
为探讨吡虫啉对绿盲蝽种群数量的控制作用,2011—2012年连续两年采用种子包衣、颗粒剂穴施和灌根处理棉花,并结合种植绿豆诱集带的方式,研究其对棉田绿盲蝽种群动态的影响。在吡虫啉有效成分用量为1 500 g/hm2时,棉花颗粒剂穴施+绿豆诱集带颗粒剂穴施、灌根和颗粒剂穴施3种处理,对棉田绿盲蝽种群数量控制作用较好,自棉花苗期至8月中旬花铃期百株绿盲蝽数量分别为12、15、17、8、19头,均低于为害经济阈值,控制有效期接近110 d;在吡虫啉有效成分用量为900 g/hm2时的棉花颗粒剂穴施、灌根处理以及吡虫啉有效成分用量为675 g/hm2的棉花种子包衣+绿豆诱集带种子包衣处理,对棉田绿盲蝽种群数量控制作用次之,控制期在100 d左右。单一棉花种子包衣处理控制效果低于上述处理,持效接近90 d。各处理对棉叶受害指数减退率的影响与其对绿盲蝽种群数量的控制结果基本一致,表明棉田吡虫啉颗粒剂穴施及液体制剂灌根施药是控制绿盲蝽为害的有效施药手段。  相似文献   

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