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1.
The African spider plant (Gynandropsis gynandra L. (Briq)) has repellent properties against spider mite on roses (Rosa hybrida L.) when grown as a companion plant. Gas chromatography–mass spectrometry (GC–MS) has been used to identify potential volatile compounds in the foliar emissions of this plant that may contribute to the anti-mite properties. Acetonitrile (methyl cyanide) was the most abundant compound emitted by entire plants and detached leaves of five lines of both glasshouse- and field-grown G. gynandra, with only trace levels emitted by roses grown under similar conditions. A toxicity bioassay was conducted to evaluate the bioactivity of acetonitrile against spider mite, and ≥2.5 μL/L of air rendered 100% of the mites inactive. Removal of the compound after an initial exposure of up to 5.0 μL/L of acetonitrile allowed some 10% of the mites to recover mobility, but above this level no mobility was observed. This study provides a very strong indication that foliar emissions of acetonitrile by G gynandra are responsible, to a significant degree, for the spider mite repellent activity of the plant when used as an intercrop with roses. 相似文献
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ABSTRACTField experiments were conducted in 2013 and 2014 to evaluate the predation efficacy of four commercially available predatory mites (Phytoseiidae): Phytoseiulus persimilis, Neoseiulus californicus, N. fallacis, and Amblyseius andersoni, for control of twospotted spider mite (Tetranychus urticae Koch) and Lewis spider mite (Eotetranychus lewisi) in strawberries. In the 2013 experiment, a grower standard treatment (P. persimilis and N. californicus) was compared to single treatments of each phytoseiid species. The 2014 experiment excluded N. fallacis as a treatment, but all other treatments are the same as in 2013. For both seasons, all treatments decreased both two-spotted and Lewis spider mite populations immediately after releases equivalently. However, none of the treatments tested were able to keep twospotted and Lewis spider mite populations below the economic threshold level. These findings indicate that several releases will be needed throughout the growing season in order to maintain spider mite levels below the economic thresholds. 相似文献
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In Scotland the raspberry leaf and bud mite (Phyllocoptes (Eriophyes) gracilis ) is widespread on cultivated and wild raspberries. However, feeding damage to leaves and fruits is usually observed only on raspberries grown in sheltered situations, where mites tend to aggregate. Female mites overwinter in the buds, under bud scales or in petiole scars. In the spring they disperse to the emerging foliage of the fructo-canes where they feed and lay eggs. Populations reach a maximum on the fructo-canes in mid-July, when the first fruits are maturing, and on the primo-canes in late September. Migration to the overwintering sites begins in late September. Cultivars differ in the extent to which they support overwintering populations and show symptoms of infestation. 相似文献
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Fruit tree red spider mites, Panonychus ulmi (Koch), were caged on the upper or lower surface of plum or apple leaves; the speckles resulting from their feeding were visible only from the surface on which they fed. Histological studies revealed that mites on the lower surface do not damage the uppermost layer of palisade mesophyll cells. Mites on both surfaces at first feed predominantly on tissues close to the veinlets, damaging mesophyll and bundle sheath cells. Bronzing, which develops later, is associated with damage to mesophyll cells further from the veinlets. Larger speckles are seen when mites have fed on leaves when they were still expanding, causing cells adjacent to those directly damaged to develop abnormally, and the leaves are distorted locally; in some cases a phellogen is formed. 相似文献
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J. R. Chiswell 《The Journal of Horticultural Science and Biotechnology》2013,88(4):313-325
In field trials carried out from 1956 to 1958 various insecticides were compared with DDT and lead arsenate to assess their efficiency against codling moth. In each trial sprays were applied to replicated single-tree plots in late June and again three to four weeks later.Against codling moth, 0.04% azinphos-methyl and 0.1% Sevin were as effective as 0.1% DDT, and all three were more effective than 0.2% lead arsenate; 0.6% ryania was as effective as 0.2% lead arsenate but was less effective than 0.1% DDT. In a single trial 0.02% diazinon gave control comparable with that given by 0.1% DDT. In 1958, damage caused by larvae of the partial second generation, which began to hatch about six weeks after application of the second spray, was significantly reduced by DDT and Sevin, but not by azinphos-methyl or lead arsenate. Laboratory tests of the toxicity to young larvae of fresh and field-weathered deposits on fruit gave results consistent with those obtained in the field trials.Populations of the fruit tree red spider mite increased considerably on trees treated with DDT or Sevin, and smaller but significant increases were observed after treatment with diazinon and, in some trials, ryania. Lead arsenate had little or no effect on mite populations, and azinphosmethyl gave control of mites for two to three months. 相似文献
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番茄刺皮瘿螨对番茄叶片生理指标的影响 总被引：3，自引：0，他引：3
番茄叶片被番茄刺皮瘿螨危害后, 一些生理生化指标发生了变化。与对照相比叶绿素、可溶性糖含量下降, 螨量大和危害时间长则下降速度快。少量瘿螨在短时间内危害导致可溶性蛋白质和游离氨基酸含量上升, 且随着螨量增加和危害时间的延长含量增加, 而危害时间过长, 其含量则下降。对于游离脯氨酸, 则是螨量大, 危害时间长其含量增加快。危害期为6 d, 处理20头/叶与60头/叶的游离脯氨酸含量分别比对照增加31.7887%、82.0439%。 相似文献
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O. Bonato J. Baumgartner J. Gutierrez 《The Journal of Horticultural Science and Biotechnology》2013,88(6):1089-1094
Growth of cassava was investigated in Central Africa (Congo) on crops attacked by two phytophagous mites: Mononychellus progresivus and Oligonychus gossypii. Change and distribution of dry matter in leaves, stems and roots were monitored for the 24 month crop cycle on infested and mite-free plants. Leaf dry matter increased during the rainy season and decreased during the dry season. Stems contain the reserves used for initiating plant growth after the dry season. Dry matter increased in the roots which form true storage organs. At the start of the second year of cultivation, one third of the root biomass was used to support the recovery of plant growth and development. Mite densities fewer than 50 mobile forms per leaf (maximum number of mites) were not sufficient to cause significant loss of leaf, stem and root dry matter. Nevertheless the mites diverted part of the biomass allocated to the roots thereby reducing the efficiency of storage root production in the infested plot. 相似文献
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A. T. Jones S. C. Gordon D. L. Jennings 《The Journal of Horticultural Science and Biotechnology》2013,88(4):523-528
Tayberry plants showing conspicuous chlorotic blotches, ringspots, leaf distortion and lacking vigour were found at two sites in Scotland. The severity of the symptoms and the number of plants affected increased annually and reached 100% incidence at one site. No mechanically transmissible virus was detected in affected plants, but many such plants and some symptomless ones contained viruses indistinguishable in Rubus indicator plants from black raspberry necrosis, raspberry leaf mottle and raspberry leaf spot viruses. Propagants from healthy tayberry plants graft-inoculated either with these three viruses, singly and in combinations, or with scions from symptom-bearing tayberry, showed a faint chlorotic mottle when grown outdoors or in an unheated glasshouse but none developed the severe symptoms observed in the field. Leaves and buds of field-affected plants were found to be infested with large numbers of eriophyid mites at both sites. A single application of vamidothion to affected plants at one site resulted in significantly fewer mites and less severe symptoms on fruiting canes and primocanes than on unsprayed plants in the year of spraying and a further decrease in symptoms in the following year. The symptomatology, occurrence in Scotland and the decrease in symptoms following the application of vamidothion indicate that the disorder is caused by infestations by the leaf and bud mite (Phyllocoptes gracilis). 相似文献
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本文对柑桔红蜘蛛发生期及发生量与气象条件的关系进行了定量研究。结果表明，其发生早迟与轻重主要受冬春雨日多少的影响，雨日少，红蜘蛛将提早、加重发生；雨日多，则抑制其发生。建立了柑桔红蜘蛛达到１．５头／叶时期及年最大发生量的预报模型。 相似文献
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Cafer Köse Adem Güneş Özkan Kaya Nurgül Kıtır Metin Turan Fikrettin Şahin 《Erwerbs-Obstbau》2018,60(1):3-10
This study was conducted to determine the effects of plant growth promoting bacteria (PGPR) and boron (Bio-B) on the plant freeze injury, antioxidant enzyme activity and fruit yield of grapevine cultivar. The experimental plot was a completely randomized design with 5 replicates. As a trial model Bio-B and control were used as fertilizer agent. Bio-B fertilizer has been applied in different ways as soil?+?foliar, soil and foliar application methods to grapevine plants. Data through 2 years trials results showed that the use of Bio-B significantly decreased freeze injury and increased antioxidant enzyme activity of grapevine leaf. The highest damage rate at control group occurred with ?20?°C and 94.89% ratio. In the same temperature degree at grape plant, the damage ratio of the Bio-B application from soil decreased by 21.55%; the application from leaf by 25.53% and with the application from soil?+?leaf by 26.24%. In addition to this, compared with control, in the CAT, POD and SOD enzyme activities increases occurred with the ratios as 28.57%, 22.05% and 39.25%, respectively. Generally, as results of this study under field conditions, Bio-B fertilizer application decreased freeze injure and increased antioxidant enzyme activity of the grapevine plant. 相似文献
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N. J. Bostanian C. Vincent 《The Journal of Horticultural Science and Biotechnology》2013,88(4):459-463
SummarySeveral acaricides were evaluated for their effect on the European red mite, Panonychus ulmi Koch, and the apple rust mite, Aculus schlechtendali (Nalepa) in an experimental apple orchard. Fenbutatin oxide and cyhexatin were the most effective among the registered products. BAY SLJ 0312, which is a benzenamine compound, and clofentezine were the best among the new compounds. Early season activity of these two compounds against phytophagous mites makes them ideal candidates for development as ecologically selective acaricides for use in apple orchards. 相似文献
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柑橘锈螨广泛分布于世界各大柑橘产区,为害柑橘果实后形成黑皮果。以‘沃柑’正常果和锈螨为害果为试验材料,采用扫描电镜、顶空固相微萃取-气质联用等技术分析2种试验材料在微观结构和挥发油成分方面的差异。结果表明:柑橘锈螨为害‘沃柑’果皮引起表皮出现龟裂,果皮微观结构被破坏。‘沃柑’正常果皮共检测出75种成分,包括萜烯烃类(65.89%)、醇类(6.94%)、酯类(3.59%)、醛类(2.89%)、烷烃类(1.02%)、酸类(0.40%)、酮类(0.58%)、酚类(0.29%),分别有20、19、15、8、4、3、3、3种成分;柑橘锈螨为害果共检测出79种成分,其中萜烯烃类(59.86%)、酯类(4.04%)、醇类(3.59%)、醛类(2.61%)、烷烃类(1.58%)、酸类(0.76%)、酮类(0.33%)、醚类(0.07%)、酚类(0.03%)分别有18、21、18、8、2、1、7、3、1种成分,2种试验材料的挥发油成分在种类及含量上存在差异。表明柑橘锈螨为害造成柑橘果皮结构和成分差异,可为研究柑橘果实抗黑皮果机理提供理论参考。 相似文献
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S. Simon P. E. Lauri L. Brun H. Defrance B. Sauphanor 《The Journal of Horticultural Science and Biotechnology》2013,88(4):765-773
SummaryCentrifugal training, based on the extinction procedure, is an innovative type of apple tree training recently used in French apple orchards. A thinning cut of fruiting spurs along the trunk and on the proximal and underside parts of the fruiting branches modifies the within-tree leaf density and light environment, which is likely to affect the development of some apple pests and pathogens. In this study, development of the most serious foliar pests (aphids, mites) and disease (apple scab) was assessed over 3 years in an organic apple orchard with two training systems: the centrifugal training (CT) system, and the Original Solaxe (OS) system, using a bent axis with no removal of fruiting spurs, as a control. Infestation levels were significantly lower in 2002 and 2004 in the CT system than in the OS system for the most prevalent pest, the rosy apple aphid, Dysaphis plantaginea and, in 2003, for the red spider mite, Panonychus ulmi. Infestation by the green apple aphid, Aphis pomi, was higher in June 2002 and 2004 and lower in June 2003 in the CT system, compared to the OS control. The incidence of apple leaf scab was lower in the CT system than in the OS control in Spring 2002 and Spring 2004; but, later in the Summer, it increased more in CT trees, resulting in no difference between training systems in the levels of fruit infection at harvest. Hypotheses considered were based mainly on: (i) the removal of pests or inoculum due to the thinning cut of fruiting spurs for CT trees; (ii) effects on within-tree microclimate, providing a more aerated canopy in the CT system; (iii) shoot density and distribution, allowing greater distances between growing shoots in CT trees; and/or (iv) the shoot growth dynamics, allowing the presence of attractive or susceptible leaves in late June. Since the most serious apple pests and diseases were less prevalent in the CT system over the 3 years of the experiment, CT may prove to be a complementary, sustainable means to contribute to crop protection, especially in organic or integrated pest management orchards. 相似文献
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《Scientia Horticulturae》2005,103(2):249-255
Bromeliad growers report severe leaf quality problems for Aechmea cultivars grown under commercial greenhouse conditions. In this research, a leaf damage ‘sensitive’ and ‘insensitive’ A. cultivar were compared for their C-metabolism and hydrophysiology under these greenhouse conditions. Stomata opening index indicated CAM (Crassulacean acid metabolism) for both cultivars, with 45–50% open stomata around 4:00 a.m. and 5–10% in the afternoon. Malic and citric acid were the major organic acids present in the leaves, with diurnal malic acid accumulation during the night. The leaf damage ‘sensitive’ cultivar showed higher malic acid accumulation than the ‘insensitive’ cultivar (200 μmol/gfw versus 170 μmol/gfw). Leaf osmotic potential and turgor pressure were linked with diurnal malic acid fluctuations: organic acid accumulation during the night generated high leaf turgor pressures (up to +0.86 MPa).A leaf damage sensitivity test was designed and confirmed previous experiences of several bromeliad growers. Both cultivars showed higher leaf damage percentages (98 and 78%) when leaf malic acid accumulation was high. We attribute this elevated sensitivity to lethal turgor pressures and consider them to be caused by the water capturing mechanism generated by high organic acid accumulation. Under current greenhouse conditions, this water capturing mechanism can be disastrous for plant leaf quality. Especially, under high relative humidity, hindering plant transpiration and stimulating water uptake by dew formation, leaf quality could be endangered. 相似文献
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Field experiments were performed with tulips (‘Merry Widow’, size 8 to 9 cm, type A) to study the effects of plant density on dry matter production, bulb production, leaf formation and stem development. Dry matter production proved to be linearly related to the degree of soil coverage, and was 256 kg · ha?1 · day?1 at 100% soil coverage. leaf area was independent of plant density, but leaf and stem sizes reacted sharply.A graphic model for the effect of leaf area per plant on the reaction of daily production to plant density is given. 相似文献
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Micropropagation studies on Zamioculcas zamiifolia Engl. (ZZ) as to the position and orientation of leaflet explants and plant growth regulators were carried out. Explants consisted of leaflet lamina from the basal or apical part of the leaflet with or without petiolule or midrib that were placed vertically into the medium except for the explants with midrib from the basal part of the leaflet that were placed horizontally as well. The explants were cultured on solid Murashige and Skoog medium (MS) with 30 g l−1 sucrose, supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) at 2 or 4 mg l−1 and 6-benzyladenine (BA) at 0 or 4.44 μM in all (four) possible combinations, or with 1-naphteleneacetic acid (NAA) at 0 or 5.38 μM and BA at 0 or 4.44 μM in all (four) possible combinations (establishment medium). The morphogenic response was direct from all types of leaflet explants and varied only with respect to different plant growth regulators of the medium: 2,4-D combined or not with BA formed somatic embryo-like structures; NAA alone produced tubers and roots; BA alone resulted mainly in leaves; NAA combined with BA produced mainly roots. The intensity of the response varied accordingly to the explant type and orientation. Explants with petiolule or midrib from the basal part of the leaflet showed the highest morphogenic response compared to explants without petiolule or midrib or to explants from the apical part of the leaflet, in all the plant growth regulator combinations used. Explants with midrib from the basal part of the leaflet placed vertically into the media showed higher morphogenic response compared to those placed horizontally on the medium surface. With the objective to regenerate plantlets, explants were subcultured on MS with NAA and BA at various concentrations based on the explant response in the establishment medium, taking into consideration the initial explant type. The initial explant type did not affect the response in the subculture. Most plantlets (a tuber with roots and one leaf with one pair of leaflets) were produced by explants with embryo-like structures induced in a medium with only 2,4-D. Explants with tubers induced in a medium with NAA gave plantlets at 65–85% when subcultured in a medium with 4.44 μM BA alone or in combination with 2.69 μM NAA. Explants with leaves induced in a medium with BA and explants with roots induced in a medium with NAA and BA gave plantlets at low percentages (20–40%). The best response was produced by explants with embryo like structures induced in a medium with only 2,4-D which gave plantlets at 100% when subcultured in the medium with 2.69 μM NAA and 2.22 μM BA. Plantlets raised in different treatments were transplanted ex vitro after 22 weeks and exhibited 80–100% survival. 相似文献
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通过对不同化学防治水平苹果园叶螨种群数量的调查、室内杀虫(螨)剂对叶螨相对毒性的测定以及对叶螨在苹果叶片上的分布及为害性状的考察表明:①频繁施用杀虫(螨)剂的果园.苹果全爪螨的种群数量明显大于李始叶螨种群数量;施用杀虫(螨)剂次数少的果园,李始叶螨的相对数量均高于苹果全爪螨;多年不喷洒杀虫(螨)剂的果园.李始叶螨种群数量占绝对的代势.②苹果全爪螨对三氯杀螨醇的扰性显著强于李始叶螨.③李始叶螨和苹果全爪螨在苹果叶片上存在着相互干扰.营养竞争等现象.进而证实田间大量使用三氯杀螨醇是促使兰州苹果园叶螨优势种演变的主要原因.并对压低苹果全爪螨发生基数和控制苹果园叶螨的防治对策进行探讨. 相似文献