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1.
Five bacterial isolates collected from dogwood leaves were evaluated for powdery mildew control in shadehouse and greenhouse environments by using foliar sprays and/or root drenching. Two isolates displayed superior bioactivity and suppressed powdery mildew similar to conventional fungicide thiophanate methyl (Cleary’s 3336F®). The two bacteria disrupted powdery mildew spore germination and ruptured spore membranes causing spore lyses. Bacterial filtrates without bacterial cells were also effective in suppressing powdery mildew and disrupting spore germination and suggested the involvement of secondary metabolites. The two biocontrol agents (BCAs) colonized roots endophytically and promoted plant growth.  相似文献   

2.
Biological control of plant pathogens on strawberries may be improved by the simultaneous application of different biological control agents (BCAs). Therefore, the compatibility of various BCAs which had previously shown to be effective against powdery mildew (Podosphaera aphanis (Wallr.) U. Braun & S. Takam) under laboratory conditions was examined in vitro. Inhibitory effects between fungal and bacterial BCAs were demonstrated in dual culture tests on two solid nutrient media. Leaf disc assays with single and multiple strain treatments demonstrated either unaffected or significantly improved control of P. aphanis for many multiple strain treatments, even if antagonistic interactions previously occurred in dual culture tests. Highest inhibition of powdery mildew conidiation (80.7% reduction) was achieved with multiple strain treatments with Bacillus subtilis FZB24 and Metarhizium anisopliae (p < 0.001). In this combination, conidiation was 3.7 times lower than in single treatments with B. subtilis indicating synergistic interactions between these BCAs. Combinations of Trichoderma harzianum T58 and B. subtilis FZB24 showed antagonistic interactions in dual culture tests as well as in leaf disc assays. In this combination, powdery mildew conidiation on leaf discs was four times higher compared to single treatments with T. harzianum T58.  相似文献   

3.
To determine the most sensitive spectral parameters for powdery mildew detection, hyperspectral canopy reflectance spectra of two winter wheat cultivars with different susceptibilities to powdery mildew were measured at Feekes growth stage (GS) 10, 10.5, 10.5.3, 10.5.4 and 11.1 in 2007–2008 and 2008–2009 seasons. As disease indexes increased, reflectance decreased significantly in near infrared (NIR) regions and it was significantly correlated with disease index at GS 10.5.3, 10.5.4 and 11.1 for both cultivars in both seasons. For the two cultivars, red edge slope (drred), the area of the red edge peak (Σdr680−760 nm), difference vegetation index (DVI) and soil adjusted vegetation index (SAVI) were significantly negatively correlated with disease index at GS 10.5.3, 10.5.4 and 11.1 in both seasons. Compared with other parameters, Σdr680−760 nm was the most sensitive parameter for powdery mildew detection. The regression models based on Σdr680−760 nm were constructed at GS 10.5.3, 10.5.4 and 11.1 in both seasons. These results indicated that canopy hyperspectral reflectance can be used in wheat powdery mildew detection in the absence of other stresses resulting in unhealthy symptoms. Therefore, disease management strategies can be applied when it is necessary based on canopy hyperspectral reflectance data.  相似文献   

4.
为了解新疆小麦白粉病菌群体多样性及其间关系,利用ISSR分子标记对2020年喀什、阿克苏、和田、昌吉、塔城共5个地区13个县市小麦白粉病菌群体进行遗传多样性研究。结果表明,喀什、阿克苏、和田、昌吉、塔城小麦白粉病菌群体的遗传距离为0.031 7~0.094 5,塔城与阿克苏群体的遗传距离最近,和田与喀什的遗传距离最远;总体Neis遗传多样性指数为0.257 1,群体Neis内遗传多样性指数为0.217 5,群体内的遗传变异占总体变异的84.60%,表明遗传变异主要来源于群体内。群体间基因流Nm值为2.749 0,表明新疆不同区域群体存在一定的基因交流。Normalized Mantel Statistic分析表明,小麦白粉病菌群体间遗传距离与地理距离相关性不大。  相似文献   

5.
Pm4是我国目前有效的小麦抗白粉病基因之一,该基因对陕西关中当前流行的白粉病菌系关中4号表现高抗。本研究利用与Pm4基因紧密连锁的STS470分子标记对7个小麦品种间的6个杂交组合F3代单株进行分子标记检测并结合田间抗性鉴定筛选出抗病单株14个。对由这14个单株衍生出的64个F5代品系进行分子检测和田间抗性鉴定,发现53个品系表现抗病,占总品系的82.81%,其中51个抗病品系可以检测到与Pm4基因紧密连锁的STS470特异带,占总品系的79.69%。本研究结果表明,STS470是Pm4基因的可靠标记,可有效的用于分子标记辅助育种。  相似文献   

6.
Adequate spray deposition on susceptible grapevine tissue is an essential requirement for effective chemical control of economically important diseases, such as grey mould, powdery mildew and downy mildew. The objective of this study was to evaluate the potential of some agricultural adjuvants to improve foliar spray deposition. Deposition quantity and quality was assessed by means of a spray assessment protocol using fluorometry, photomicrography and digital image analyses. The visual droplet rating technique developed by G Furness, Australia, was also included in initial assessments. Both assessment protocols showed that spray deposition quantity increased with increasing spray volume applications of 27 l ha−1 to 581 l ha−1 with a motorised backpack mistblower, but decreased at 698 l ha−1, possibly due to run-off. Addition of selected spray adjuvants at 526 l ha−1 volume demonstrated improved deposition quantity and quality. Agral 90 (ethoxylated alkylphenol), BB5 (acidifier), Nu-film-P (terpene oil), and Solitaire (silicone/plant oil) significantly improved deposition on upper and lower leaf surfaces compared with the fenhexamid-only and water sprayed control. Break-thru S240 (organosilicone) and Villa 51 (alkylpolyethylene glycol ether) did not improve deposition quantity, although remarkably better deposition quality was obtained. An adjuvant concentration effect (within the registered concentration range) was evident at spray volumes of 502 l ha−1, especially those retained on the upper leaf surfaces. Agral 90 and Nu-film-P effected significant improvement of spray deposition at the higher concentrations (18 ml and 50 ml hl−1, respectively), but not at the lower concentrations (6 ml and 20 ml hl−1, respectively). Solitaire improved deposition at the lower concentration tested (50 ml hl−1), whereas reduced deposition at the higher concentration (100 ml per hl−1) was attributed to excessive spray run-off. No significant improvement of spray deposition was observed for both concentrations tested with Villa 51 (50 and 100 ml hl−1). Spray mixtures with adjuvants Agral 90 and Solitaire yielded similar deposition values at 500 l ha−1 compared with the fenhexamid-only control at 720 l ha−1, but reduced deposition at the higher spray volume, possibly due to spray run-off. This study clearly demonstrated the potential of adjuvants to improve deposition quantity and quality, but highlights the necessity to match adjuvant concentrations and application volumes on the spray target to achieve maximum spray deposition.  相似文献   

7.
Studies were made at Presque Isle, Maine, 1962–1966, to determine the suppressive effects of several materials against spread of the potato leaf roll cirus,Corium solani Holmes, transmitted by the green peach aphid,Myzus persicae (Sulzer), when applied as foliar sprays to Kennebec, Green Mountain, or Chippewa potatoes in field cages or in field plots. The early cage tests showed that spray mixtures containing 1% of the systemic plant growth regulant chlorocholine chloride (2-chloroethyltri-methylammonium chloride) or 1% of mineral oil were more effective than the insect antifeeding compound AC-24,055® (=ENT-25,651), the aphid-repellent compounds ENT 20,430 or ENT 21,178, or the surfactants Sarkosyl-O® (bis (2-ethylhexyl) sodium sulfosuccinate) or Aerosol-OT® (CH3 (CH2)n CON (CH3) CH2 COOH). Field tests disclosed that chlorocholine chloride at 5.2 lb or 2.6 lb/a/a was more effective when healthy green peach aphids were placed on infector plants in the plots soon after the plants were sprayed, 1 week later, or soon after the 2nd of 2 weekly applications than when the aphids were introduced before spraying. The difference in leaf roll suppression at these two dosages was not significant at the 5% level; as high as 90% control of leaf-roll spread was obtained. When only natural infestations of aphids were involved and field spread of the virus was light, the 86% control of leaf roll spread that was obtained from 4 weekly applications made in late June and in July was not significantly different (P=0.05) from the 79% control obtained from 2 biweekly applications made during the same period of time. The potato plants soon recovered from the slight chlorosis resulting from the spray treatment and there was no reduction in weight of US 1 tubers at harvest. Aphid population trends in treated plots were not affected.  相似文献   

8.
Potassium phosphite for control of downy mildew of soybean   总被引:1,自引:0,他引:1  
Downy mildew of soybean, caused by Peronospora manshurica, is widely spread throughout Brazil. The objective of this study was to evaluate the use of potassium phosphite to control this disease. Field experiments were conducted during the growing season of 2006/2007 and 2007/2008 in the state of Parana in southern Brazil. The experimental design consisted of completely randomized blocks in a factorial arrangement (4 × 2) with four replications. Four rates of potassium phosphite (0, 375, 750 and 1500 g P2O5 + K2O ha−1) were applied at two growth stages, V6 (fifth trifoliolate leaf) and R2 (full flowering), followed by one or two applications of pyraclostrobin and epoxiconazole (66.5 + 25 g a.i. ha−1) at R3 (pod development) or R2 and R5.1 (10% of pod filling), mainly for the control of Asian soybean rust (Phakopsora pachyrhizi) and powdery mildew (Microsphaera diffusa). Field experiments were conducted to quantify the severity of downy mildew on leaves, nutrient content in leaf tissue (N, P and K), leaf area index (LAI), yield and seed weight. The maximum severity of downy mildew was observed at a growth stage of R5.3 (50% of pods were ripe), with 14% and 46% of the leaf area affected in 2006/2007 and 2007/2008, respectively. Also it was detected some effect of phosphite on Asian rust control but it was mostly in the trial of 2007/08 when the epidemic was very low (9.7-21.8% of severity). There was a linear reduction in the severity of downy mildew and a significant improvement in the LAI with an increase in the rate of phosphite applied. During the 2006/2007 growing season, a significant yield improvement was observed due to the application of the highest rate of phosphite. Two fungicide applications following phosphite application significantly improved the control of Asian soybean rust and powdery mildew, yield and seed weight when compared to a single fungicide application.  相似文献   

9.
The commercial mycopesticide, Vertalec® based on Lecanicillium longisporum, was evaluated for simultaneous control of aphids and powdery mildew on cucumbers in a greenhouse setting where temperature and RH were allowed to fluctuate within normal operating ranges. Five to six week old cucumber plants were inoculated with either Sphaerotheca fuliginea (Sf) spores, cotton aphids (Aphis gossypii) or both. Vertalec, Vertalec containing irradiation-inactivated blastospores (II Vertalec) or sterilized water (control) were applied to the plants 1, 4, and 7 days later. Vertalec treatment provided complete control of aphids 16 days after aphid inoculation, whereas effects of the II Vetalec were not significantly different from the water-treated control. The number of powdery mildew spots on cucumber leaves and the number of S. fuliginea spores in each spot were significantly lower in Vertalec-treated plants than II Vertalec-treated plants or the controls, whereas numbers in the II Vertalec treatment were lower that the untreated control. These results demonstrate that Vertalec has potential for simultaneous management of both cotton aphid and powdery mildew in greenhouse cucumber production.  相似文献   

10.
The systemic insecticides, Dasanit®, carbofuran (Furadan®), phorate (Thimet®), aldicarb (Temik®) and disulfoton (Di-Syston®) were applied in the planting furrow at 2–3 lb actual/acre for potato tuberworm (Phthorimaea operculella (Zeller)) control in Irish potato foliage. None of these compounds gave entirely satisfactory results. Dasanit was the best with slightly over 80% decrease in the number of mines and was followed closely by carbofuran; all treatments needed to be supplemented by foliage sprays for satisfactory tuberworm protection. Azinphosmethyl (Guthion®) gave consistently outstanding results as a foliage spray at 0.5 lb/acre with over 99% tuberworm reduction. Other foliar-applied insecticides giving at least 98% tuberworm control included: Monitor®, monocrotophos (Azodrin®), phosphamidon, Orthene®, Torak®, methomyl (Lannate®) and Dursban® (all at 0.5 lb/acre) and Phosvel® (1 lb/acre).  相似文献   

11.
CIMMYT小麦材料的白粉病抗性鉴定与抗原筛选   总被引:1,自引:0,他引:1  
1998-2000年连续2年,对CIMMYT提供的165份小麦品种进行成株期田间人工诱发抗白粉病鉴定,筛选出对小麦白粉病菌高抗-银川市的材料12份,占7.27%,其中高抗材料3份,为Bola2973,Atay85,Patria;免疫材料9份,为Beiostaya,Nanbukomugi,Gerek79,HYS/CNDR,BOLI/TAM200,Vorona/TR810200,Tremie,Fatima,MV.Palma。这些材料抗病性表现稳定,可用作抗白粉病育种杂交亲本。  相似文献   

12.
源自苏联的波斯小麦Cypa35-3对陕西关中地区白粉菌优势小种表现为成株期高抗白粉病。为明确Cypa35-3抗白粉病基因所在染色体位置及其抗白粉病基因的遗传规律,利用Cypa35-3与高感白粉病的加拿大二粒小麦Flavescens进行杂交,在成株期自然发病条件下对亲本及其杂交F1、F2、F2∶3群体进行白粉病抗性评价与遗传分析;选用分布于A、B染色体组14对染色体上共计601对SSR标记,利用分离群体分组分析法(BSA)对Cypa35-3的F2群体进行多态性标记筛选。结果表明,Cypa35-3的成株期白粉病抗性受1对显性基因控制,暂命名为PmCypa35-3。通过群体筛选,获得4对位于1B染色体上的SSR标记,分别为Xbarc81、Xcfd48、Xbarc61、Xbarc302,其中Xbarc81、Xcfd48位于PmCypa35-3两侧,遗传距离分别为25.2 cM、8.6 cM。由此将成株期抗白粉病基因PmCypa35-3初步定位于1B染色体。通过与1B染色体上及波斯小麦中正式命名的抗白粉病基因...  相似文献   

13.
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   

14.
长江中下游麦区是中国弱筋小麦优势产业带,小麦赤霉病、白粉病和条锈病是该麦区主要病害,当前弱筋小麦主导品种综合抗性较弱,影响其生产安全。为培育多抗优质弱筋小麦品种,以高产中筋小麦品种扬麦16为轮回亲本,以兼抗白粉病、条锈病的软质小麦92R137为供体亲本,构建了BC1群体,利用分子标记在BC1F2代基础农艺性状较优良的株行中筛选抗白粉病基因 Pm21、抗条锈病基因 Yr26和软质麦相关基因 Pinb-D1a均纯合的单株,并鉴定BC1F6代对赤霉病、白粉病和条锈病的抗性,同时检测籽粒硬度、湿面筋含量、面团形成时间、稳定时间等重要品质指标以及小区产量,最终育成高抗赤霉病、免疫白粉病和高抗条锈病的弱筋小麦新品种扬麦38,于2022年通过国家农作物品种审定委员会审定。  相似文献   

15.
India is a leading producer of oilseed Brassicas, contributing approximately 23 percent of the country's total oilseed production. In India, the Indian mustard [Brassica juncea (L.) Czern. & Coss.] crop is ravaged by various diseases, including Alternaria blight, white rust, downy mildew, Sclerotinia rot and powdery mildew, which can contribute to fluctuations in crop yields. A field experiment examining an integrated disease management system for Indian mustard (B. juncea) was conducted under the All India Coordinated Research Project on Rapeseed-Mustard (Indian Council of Agricultural Research or ICAR) during three crop seasons (2006–09) at 11 locations to assess treatments suitable for the management of crop disease. The data from the different locations and years regarding disease severity and incidence were pooled and analyzed. Seed treatments with freshly prepared Allium sativum bulb aqueous extract (1 percent w/v) resulted in significantly higher initial plant stands, across locations and years. Seed treatment with A. sativum bulb extract, followed by its use as a foliar spray, resulted in significantly reduced Alternaria leaf and pod blight severity, reduced white rust severity, fewer stag heads per plot, reduced downy mildew and Sclerotinia rot incidence, and reduced powdery mildew severity, across locations and years. The combination also provided significantly higher seed yields compared with the control across locations and years and was at par with treatment by chemical fungicides. The combination used in the present study was as effective as the combination of seed treatment with Trichoderma harzianum and foliar spraying with Pseudomonas fluorescens and T. harzianum. Economic returns were higher when using biorational treatments (A. sativum bulb extract, T. harzianum, P. fluorescens) compared with chemical fungicides. The combination of seed treatments with T. harzianum followed by its use as a foliar spray (17.22), and the similar combination of seed treatments and foliar spraying with the A. sativum bulb extract (17.18), resulted in a higher benefit to cost ratio. This eco-friendly technology can help oilseed Brassica growers in India safeguard the crops from major diseases and increase the stability and productivity of the Indian mustard crop.  相似文献   

16.
Powdery mildew of mango, incited by the fungus Pseudoidium anacardii (F. Noack) U. Braun & R.T.A. Cook 2012 (formerly known as Oidium mangiferae Berthet), is one of the most common, widespread and serious diseases throughout the world and causes significant yield losses. Symptomatology, biology, and etiology of powdery mildew and its control through fungicides have not been widely studied, and substantial information is still required on the inoculum potential, growth models and epidemiological parameters of powdery mildew, influence of changing climate, impact of extensive use of fungicides and disease resistance. These critical factors may influence the development and emergence of diverse isolates of O. mangiferae including fungicide-resistant strains. Mango varieties differ slightly in their reaction to powdery mildew but a source of resistance has not been identified. In view of the increasing demands of mangoes in the world, control of powdery mildew is gaining importance. The present review treats briefly different aspects of powdery mildew disease with major emphasis on its ecology, pathology, epidemiology and management. Some new approaches such as biological control, integrated management strategies and some other aspects which have not been highlighted in former reviews, are also discussed.  相似文献   

17.
由禾本科布氏白粉菌Blumeria graminis(DC.) f. sp.tritici(Bgt)引起的白粉病是影响小麦产量和品质的一种主要病害。为了评价小麦抗白粉病基因相关分子标记在育种中的有效性与实用性,本试验利用感白粉病品种晋麦66和小偃麦衍生品系CH1357构建的341个F_(2:3)家系为材料,利用本课题组前期已定位的8个与抗白粉病基因 PmCH1357相关的分子标记(Xcfd81、Xbwm20、Xbwm21、Xbwm25、Xmp510、Xbwm8、Xbwm9和Xgwm190)对群体进行PCR检测,并接种白粉菌株E09进行苗期抗病性鉴定,分析PCR扩增产物与白粉病抗性间的相关性。结果表明,4个标记(Xcfd81、Xbwm20、Xbwm21和Xbwm25)对群体检测的纯合抗病基因型与纯合抗病表现型符合率均达到93%以上,可用于抗白粉病基因 PmCH1357的筛选;为进一步提高标记筛选的准确性,可使用多个标记组合,使用基因同一侧的标记组合进行选择会降低选择效率,使用基因两侧标记组合进行选择可有效提高选择的准确性。使用标记组合Xcfd81+Xbwm8对抗白粉病基因 PmCH1357进行选择可以获得更高的准确性及更多有效植株。  相似文献   

18.
Pesticides are commonly applied by using hydraulic nozzles to generate droplets. The properties of these spray droplets can influence the effectiveness and risks associated with the use of pesticides. Initial spray characteristics (initial droplet size and velocity, fan angle and spray liquid density) were therefore measured for a range of hydraulic nozzles and spray mixtures. Particle Image Velocimetry (PIV) was used to measure the spray sheet velocity.There was a significant difference between a standard hydraulic nozzle, Turbo TeeJet® and air induction nozzle for all measured spray characteristics. The standard hydraulic nozzle generated the smallest droplet sizes, the highest velocity and the highest spray liquid density. The air induction nozzle generated the largest droplet size, the slowest velocity and the lowest spray liquid density. The type of air induction nozzle and spray formulation was also found to influence spray characteristics.This work has demonstrated that initial spray characteristics such as droplet size and velocity, liquid density, fan angle and included air can vary depending on nozzle design, operating parameters and spray formulations. Initial droplet velocity was found to be significantly correlated to droplet size (Dv0.5) and spray pressure.  相似文献   

19.
基于叶片高光谱特征的小麦白粉病严重度估算模式   总被引:3,自引:0,他引:3  
为了解白粉病胁迫下小麦叶片特征并预测其危害程度,基于大田小区和温室盆栽小麦白粉病接种试验,采用高光谱仪测定受白粉病不同程度危害的冬小麦叶片光谱反射率,并分析光谱特征参数与白粉病严重度间的关系。结果表明,随着小麦白粉病病情的加重,在可见光350~700nm波段内,叶片光谱反射率增加;而在700~1050nm近红外波段内,叶片光谱反射率明显降低。400~500nm和610~690nm为光谱敏感波段,在650~680nm波段相关系数最高(r0.75)。光谱参数MCARI、PSRI、VARIgreen和AI对叶片病害严重度拟合效果较好,决定系数(R2)变化范围为0.77~0.82,标准误差为9.34~10.14。模型检验表明,小麦单叶片病害严重度超过10%时,检验结果较为理想,单叶片病害严重度低于10%时,则定量估算误差偏大,10%严重度可作为光谱法识别小麦白粉病的临界值。光谱参数MCARI和VARIgreen对小麦白粉病反应敏感,估算误差较小,可作为小麦白粉病严重度的最佳估算模型。  相似文献   

20.
为给大麦抗白粉病育种提供参考依据,以1个感白粉病、4个抗白粉病大麦品种为亲本,按Griffing的双列杂交法Ⅰ配制20个杂交组合,在田间自然条件下研究了大麦白粉病抗性的遗传特性。结果表明,大麦白粉病抗性在杂交组合间存在显著差异。5个亲本中,木石港3号和CM72的一般配合力较好,均表现为较大的负向效应,能极显著提高杂种后代抗白粉病能力;S096的一般配合力中等,也表现为负向效应,能显著地提高杂种后代抗白粉病能力,因而这三个品种在大麦抗白粉病育种中利用价值较高。大麦白粉病抗性遗传符合加性显性模型,同时受加性和显性效应的作用,且加性效应更重要。大麦白粉病抗性的狭义遗传力较低,早代选择不宜太严。  相似文献   

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