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1.
J. Sudisha 《Pesticide biochemistry and physiology》2005,81(3):188-197
Three commercial formulations of strobilurins, viz., azoxystrobin, kresoxim-methyl, and trifloxystrobin were evaluated for their efficacy against pearl millet downy mildew disease caused by Sclerospora graminicola. In vitro studies revealed inhibition of S. graminicola sporulation, zoospore release, and zoospore motility at 0.1-2 μg ml−1 of all the three fungicides. The fungicides were evaluated for phytotoxic effects on seed quality parameters and for their effectiveness against downy mildew disease by treating pearl millet by: (1) seed dressing, (2) seed dressing followed by foliar spray, and (3) also by foliar spray alone. The highest non-phytotoxic concentrations of 5, 10, and 10 μg ml−1 for azoxystrobin, trifloxystrobin, and kresoxim-methyl, respectively, were selected for further studies. Under greenhouse conditions, these fungicides showed varying degrees of protection against downy mildew disease. Among the three fungicides, azoxystrobin proved to be the best by offering disease protection of 66%. Further, seed treatment along with foliar application of these fungicides to diseased plants showed enhanced protection against the disease to 93, 82, and 62% in treatments of azoxystrobin, kresoxim-methyl and trifloxystrobin respectively. Foliar spray alone provided significant increase in disease protection levels of 91, 79, and 59% in treatments of azoxystrobin, kresoxim-methyl, and trifloxystrobin, respectively. Disease curative activity of azoxystrobin was higher compared to trifloxystrobin and kresoxim-methyl. Tested fungicides showed weaker translaminar activity, as the disease inhibition was marginal when applied on adaxial leaf surface. Partial systemic activity of azoxystrobin was evident by root uptake, while trifloxystrobin and kresoxim-methyl showed lack of systemic action in pearl millet. A trend in protection against downy mildew disease similar to greenhouse results was evident in the field trials. Grain yield was significantly increased in all strobilurin fungicide treatments over control and maximum increase in yield of 1673 kg ha−1 was observed in combination treatments of seed treatment and foliar spray with azoxystrobin. 相似文献
2.
BACKGROUND: The present study investigated the effect of chitosan seed priming on the induction of disease resistance in pearl millet against downy mildew disease caused by Sclerospora graminicola (Sacc.) Schroet. RESULTS: Pearl millet seeds were primed with chitosan at different concentrations: 0.5, 1.5, 2.5 and 3 g kg?1 seed. Of the different concentrations, 2.5 g kg?1 was found to be optimum, with enhanced seed germination of 99% and seedling vigour of 1782, whereas the untreated control recorded values of 87% and 1465 respectively. At optimum concentration, chitosan did not inhibit sporulation and release of zoospores from sporangia. Furthermore, pearl millet seedlings raised after seed treatment with chitosan showed an increased level of the defence‐related enzymes chitosanase and peroxidase as compared with the untreated pearl millet seedlings on downy mildew pathogen inoculation. The effect of chitosan in reducing downy mildew incidence was evaluated in both greenhouse and field conditions, in which respectively 79.08 and 75.8% disease protection was obtained. CONCLUSION: Chitosan was effective in protecting pearl millet plants against downy mildew under both greenhouse and field conditions by inducing resistance against the pathogen. Thus, chitosan formulation can be recommended for seed treatment in the management of downy mildew disease. Copyright © 2008 Society of Chemical Industry 相似文献
3.
In an attempt to find a suitable alternative to the otherwise perilous chemical control strategy of disease management, the
amino acid proline was evaluated for its efficiency to elicit resistance in pearl millet (Pennisetum glaucum (L.) R. Br.) against downy mildew disease caused bySclerospora graminicola (Sacc.) Schroet both under greenhouse and field conditions. Proline treatment to seeds at 50 mM concentration for 3 h, significantly
enhanced the seed germination and seedling vigor of pearl millet in comparison with the control. The same concentration and
duration of seed treatment protected the pearl millet plants from downy mildew by offering 58% protection under greenhouse
and 67% protection under field conditions. Studies revealed that 3 days were required for proline-treated plants to develop
resistance, which was systemic and was sustained throughout the life of the plants. Apart from disease protection, proline
was also found effective in enhancing vegetative and reproductive growth of the plants, as evidenced by the increase in height,
fresh weight, leaf area, tillering capacity, 1000-seed weight and grain yield in comparison with the control plants.
http://www.phytoparasitica.org posting Oct. 3, 2004. 相似文献
4.
Downy mildew of pearl millet, caused by Sclerospora graminicola, is a devastating disease, resulting in high economic losses in the semi-arid regions of the world. Recently, induction of host plant resistance using biotic and abiotic inducers are included among disease management practices as an eco-friendly approach. Unsaturated fatty acids are considered as a new generation of plant disease resistance inducers. In the present study, six unsaturated fatty acids, viz. docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), arachidonic acid (AA), linolenic acid, linoleic acid and oleic acid, all originally detected in the zoospores of
S. graminicola,were applied to seeds of susceptible cultivars of pearl millet to examine their ability to protect against downy mildew under greenhouse and field conditions. In greenhouse experiments, EPA and AA induced a maximum of 78.6% and 76.5% protection, whereas linoleic acid, DHA and linolenic acid provided up to 66.3%, 61.2% and 24.5% protection, respectively. Oleic acid was not effective in protecting pearl millet (only 5.1% protection). A time interval of four days between treatment of seeds and challenge inoculation was required to obtain optimum protection. Plants raised from treated seeds and challenge inoculated at the tillering and inflorescence stages showed enhanced resistance, resulting in higher grain yield compared to untreated plants of the same cultivar. Chitinase activity was found to be higher in susceptible seedlings of pearl millet after treatment with the fatty acids and pathogen inoculation than in seedlings only inoculated with the pathogen. This indicates that host defence responses are activated and thus that induced resistance is involved in the protection observed. The role of unsaturated fatty acids as activators of resistance against downy mildew in pearl millet is discussed. 相似文献
5.
Nitric oxide (NO) donors Nitroso-R-Salt, 2-Nitroso-1-Naphthol and Sodium Nitro Prusside (SNP) were evaluated for their effectiveness in protecting pearl millet [(Pennisetum glaucum L.) R. Br.] plants against downy mildew disease caused by Sclerospora graminicola [(Sacc). Schroet]. Optimization experiments with NO donors showed no adverse effect either on the host or pathogen. Aqueous SNP seed treatment with or without polyethylene glycol (PEG) priming was the most effective in inducing the host resistance against downy mildew both under greenhouse and field conditions. Potassium Ferrocyanide, a structural analog of NO donor lacking NO moiety failed to protect the pearl millet plants from downy mildew indicating a role for NO in induced host resistance. Spatio-temporal studies corroborated that the protection offered by NO donor treatment was systemic in nature and a minimum of 3-day time gap between the inducer treatment and subsequent pathogen inoculation was necessary for maximum resistance development. Disease protection ability of NO donors was also validated as durable in nature. Conversely, prior-treatment with NO scavenger 2-4-carboxyphenyl-4,4,5,5 tetrazoline-1-oxyl-3-oxide potassium salt (C-PTIO) rendered the pearl millet plants relatively susceptible for pathogen infection. Expression of primary defense responses like hypersensitive response, lignin deposition and defense related enzyme phenylalanine ammonialyase −EC 4.3.1.5 (PAL) were enhanced by NO donor treatments. 相似文献
6.
The efficacy of cyazofamid was tested against pearl millet downy mildew disease caused by Sclerospora graminicola Schroet. Significant inhibition of sporangial sporulation, zoospore release and motility was observed at 0.3 mg mL(-1), and this concentration also provided good fungicidal activity under in vitro conditions. Under glasshouse conditions, none of the concentrations tested, either 0.01-2 mg mL(-1) as seed treatment or 1-10 mg mL(-1) by foliar application, was found to be phytotoxic. The effect of cyazofamid was tested by seed treatment alone, seed treatment followed by foliar application and foliar application alone. Seed treatment with cyazofamid offered only 19.7% disease control, but seed treatment followed by a single foliar application to diseased plants provided good control over disease, seed treatment with two foliar applications was significantly superior and foliar application alone showed a high level of activity, with 10 mg mL(-1) giving 97.9% disease control. Lack of systemic activity of cyazofamid was evident, root treatment giving disease levels on a par with the untreated control. The fungicide exhibited strong curative activity, but only moderate translaminar activity, with only marginal (34.8%) disease control after treatment of the adaxial leaf surface at 10 mg mL(-1). Loss of cyazofamid activity over time was very low, indicating stable residual and rainfastness activity. These results indicate that cyazofamid has a high potential to be an effective fungicide for the control of downy mildew disease of pearl millet. 相似文献
7.
Brita D. Jensen A. Olumide Latunde-Dada Donna Hudson John A. Lucas 《Pest management science》1998,52(1):63-69
Control of seedling diseases is a major priority in many crop systems. Seed treatments that induce systemic resistance after seedling emergence may be an ideal way to provide protection against disease during the establishment of the crop. CGA 245704, a chemical activator of systemic acquired resistance, was tested as a seed treatment against two Brassica diseases with contrasting infection biologies, the airborne downy mildew pathogen, Peronospora parasitica, and the soilborne fungus, Rhizoctonia solani. Seeds of two Brassica spp. were either imbibed with various concentrations of the compound or imbibed and then dried. Both the imbibition treatment alone and the imbibition treatment followed by seed drying had a significant effect on the sporulation intensity of P. parasitica for all concentrations of the compound used, whereas the imbibition treatment provided some control of damping-off caused by R. solani, with the degree of control being highly dependent on the concentration applied to the seed. Seed treatment with the plant activator CGA 245704 might therefore simultaneously control several seedling diseases, thereby providing a novel option for management of these diseases. © 1998 SCI. 相似文献
8.
‘Priming’ the plant and seed induces a physiological state in which plants are able to activate defense responses. Plant-based
exudates are excellent gum biopolymers which contain plant growth-regulating hormones with priming potential without any side
effects. In this study, gum exudates of Acacia arabica, Moringa oleifera, Carica papaya and Azadirachta indica were evaluated for synergistic effects of seed priming with exuded gum biopolymer combined with metalaxyl (Apron 35 SD) on
pearl millet seed quality, growth parameters, and resistance to Sclerospora graminicola. Seeds of 7042S were primed with gum biopolymers and metalaxyl 35 SD and evaluated under laboratory and greenhouse conditions.
Seed germination and vigor were synergistically enhanced using gum biopolymers solution (1:2 w/v) with 3 g kg−1 metalaxyl 35 SD. A. arabica and A. indica gum biopolymers alone or with 3 g kg−1 of metalaxyl 35 SD resulted in seed germination of >91%. Seed priming with 6 g kg−1 of metalaxyl 35 SD gave 89% seed germination and was not significantly different from control. A similar trend in vigor was
observed among treatments. Seed priming with gum biopolymers alone provided varied disease protection levels when compared
with the control. A. arabica or A. indica gum with 3 g kg−1 of metalaxyl 35 SD was the superior treatment, offering significant 86% disease reduction while exhibiting a growth-promoting
effect. Synergistic use of gum biopolymers and metalaxyl 35 SD by seed priming is highly effective in growth promotion and
management of pearl millet downy mildew disease. 相似文献
9.
为明确黄瓜霜霉病菌Pseudoperonospora cubensis对氟吡菌胺的抗性时空动态,2011—2016年从河北省和山东省黄瓜主产区采集1 821株霜霉病菌,采用叶盘漂浮法检测供试菌株对氟吡菌胺的敏感性,并以茎叶喷雾法评估5种常规药剂对黄瓜霜霉病的田间防效。结果表明,河北省和山东省黄瓜主产区的黄瓜霜霉病菌对氟吡菌胺已普遍产生了低度抗性,平均抗性倍数为5.86;所有供试菌株的抗性频率为51.89%,其中低抗菌株及中抗菌株分别占36.18%和15.71%;平均抗性指数为0.34,每年检测的抗性频率、抗性倍数及抗性指数呈增长趋势,且随着监测区域的变化而变化。在河北省定兴县和山东省寿光市进行的田间防效试验结果显示,按推荐剂量喷施,687.5 g/L氟吡菌胺·霜霉威盐酸盐SC对黄瓜霜霉病防效显著高于常规对照药剂68%精甲霜灵·代森锰锌WG、58%甲霜灵·代森锰锌WP、80%代森锰锌WP及250 g/L嘧菌酯SC的防效,但防效明显下降,由2011年的92.58%～93.31%降至2016年的80.07%～80.82%。表明需要制定和实施抗药性治理对策,如限制山东和河北2省黄瓜的每个生长季节中687.5 g/L氟菌·霜霉威SC的使用不超过2次,而且要与不同作用机理的卵菌杀菌剂交替使用防治黄瓜霜霉病。 相似文献
10.
beta-Aminobutyric acid (BABA) treatment of pearl millet [Pennisetum glaucum (L) R Br] seeds influenced seedling vigour and protected the seedlings from downy mildew disease caused by the oomycetous biotropic fungus Sclerospora graminicola (Sacc) Schroet. Of the different concentrations of BABA tested, viz 25, 50, 75 and 100 mM, seeds treated with 50 mM for 6 h resulted in the maximum of 1428 seedling vigour and showed 23% disease incidence in comparison with the control which recorded a seedling vigour of 1260 and 98% disease incidence i.e. 75% protection from disease. Seeds treated with BABA when challenged for downy mildew disease using zoospores of S graminicola required 48 h after inducer treatment to develop maximum resistance. Durability of induced resistance was also tested in plants raised from seeds treated with the inducer and identified as resistant, by second challenge inoculation with the downy mildew pathogen at tillers and inflorescence axes. Reduced disease incidence of only 10 and 12% in these plants, compared with 71 and 76% disease in control plants inoculated at the tillers and inflorescence axes, respectively, suggested that resistance induced in seeds with BABA remained operative through vegetative and reproductive growth of pearl millet plants. Induction of resistance by seed treatment with BABA enhanced vegetative growth, viz height, fresh weight, leaf area and tillering, and reproductive growth, viz early flowering, number of productive ear heads and 1000 seed weight. Studies on induction of resistance in different cultivars of pearl millet with varying resistance reaction to downy mildew indicated that the protection offered by BABA is independent of the nature of cultivars used and not dependent on their constitutive resistance. 相似文献
11.
Moshe Reuveni 《European journal of plant pathology / European Foundation for Plant Pathology》2003,109(3):243-251
Benthiavalicarb is a new fungicide active against Oomycetes fungal plant pathogens. The present study shows that benthiavalicarb is effective for controlling the Oomycete fungal pathogen Plasmopara viticola, which causes downy mildew in grapevines. The fungicide did not affect zoospore discharge from sporangia of P. viticola, but strongly inhibited zoospore encystment, cystospore germination in vitro and mycelial growth, together with sporangial production in vivo. Benthiavalicarb showed strong prophylactic and local activity in intact plants or detached leaves and low translaminar activity. The compound was not translocated from leaf to leaf in either a acropetal or basipetal direction. Benthiavalicarb applied at 1, 3 and 6 days post-inoculation protected grapevine plants against downy mildew and inhibited sporulation of the pathogen. Similar results were obtained on leaf disks if benthiavalicarb was applied up to 96 h post-inoculation. Benthiavalicarb diminished the sporulation of P. viticola when applied to established disease in the tissue. Benthiavalicarb remained active on leaves for a period up to 28 days. Two foliar applications of benthiavalicarb, 2 weeks apart, to field-grown grapevines inhibited downy mildew development and were as effective as the standard metalaxyl-Cu treatment in controlling the disease. A formulated mixture of benthiavalicarb + Folpet was similar or superior in performance to metalaxyl-Cu and the new strobilurin trifloxystrobin in controlling downy mildew. The effectiveness of benthiavalicarb makes it well suited for integration into a control programme against downy mildew disease in vineyards, and as a component to delay resistance buildup. 相似文献
12.
H. Banani B. Roatti B. Ezzahi O. Giovannini G. Gessler I. Pertot M. Perazzolli 《Plant pathology》2014,63(2):334-343
Downy mildew, caused by Plasmopara viticola, is one of the most destructive diseases of grapevine and is controlled with intense application of chemical fungicides. Treatment with Trichoderma harzianum T39 (T39) or benzothiadiazole‐7‐carbothioic acid S‐methyl ester (BTH) has been previously shown to activate grapevine resistance to downy mildew and reduce disease symptoms in the Pinot noir cultivar. However, enhancement of plant resistance can be affected by several factors, including plant genotype. In order to further extend the use of resistance inducers against downy mildew, the physiological and molecular properties of T39‐ and BTH‐activated resistance in different cultivars of table and wine grapes were characterized under greenhouse conditions. T39 treatment reduced downy mildew symptoms, but the degree of efficacy differed significantly among grapevine cultivars. However, efficacy of BTH‐activated resistance was consistently high in the different cultivars. Expression profiles of defence‐related genes differed among cultivars in response to resistance inducers and to pathogen inoculation. T39 treatment enhanced the expression of defence‐related genes in the responsive cultivars, before and after P. viticola inoculation. A positive correlation between the efficacy of T39 and the expression level of defence‐related genes was found in Primitivo and Pinot noir plants, while different genes or more complex processes were probably activated in Sugraone and Negroamaro. The data reported here suggest that the use of a responsive cultivar is particularly important to maximize the efficacy of resistance inducers and new natural inducers should be explored for the less responsive cultivars. 相似文献
13.
H. G. Pushpalatha J. Sudisha H. Shekar Shetty 《European journal of plant pathology / European Foundation for Plant Pathology》2013,137(4):707-717
The responses to cellulysin as an immune inducer in pearl millet that confers downy mildew resistance mediated through lipoxygenase (LOX), a jasmonate-dependent enzyme involved in defence signalling, are discussed in this paper. The susceptible pearl millet cultivar 7042S was treated with cellulysin at 10, 15, 20, 30 and 50 μg/ml concentrations. All tested concentrations showed enhanced seed germination and seedling vigour when compared with the untreated control. Maximum seed germination of 92 % and seedling vigour was obtained following 20 μg/ml cellulysin treatment. Significant (P?<?0.05) downy mildew disease protection of 67 % and 71 % was observed when cellulysin was used at 20 μg/ml under greenhouse and field conditions, respectively. Further studies showed that the resistance induced by cellulysin treatment in pearl millet plant was systemic, required a minimum of 4 days to achieve maximum resistance development after pathogen inoculation seedling inoculation (five-day-old), and was sustained throughout the plant’s life. Plants raised from cellulysin-treated seeds and challenge inoculated at tillering (25-day-old) and inflorescence (45-day-old) showed persistence in resistance till the end of the crop period. A notable increase in LOX activity was observed in all the tested concentrations of cellulysin in plants inoculated with the pathogen at 24 h, compared to the control. However, a maximum 6-fold increase in LOX activity was noticed using a cellulysin concentration of 20 μg/ml 48 hours post inoculation. In contrast, glucanase (GLU) activity was high in control inoculated seedlings, but was low in cellulysin treated samples at all time intervals. The optimal cellulysin treatment (20 μg/ml) provided enhanced vegetative and reproductive parameters that resulted in higher yield compared to the untreated control. 相似文献
14.
Barbara Thuerig Andres Binder Thomas Boller Urs Guyer Sonia Jiménez Christina Rentsch Lucius Tamm 《European journal of plant pathology / European Foundation for Plant Pathology》2006,114(2):185-197
We have examined the effect of Pen, an aqueous extract of the dry mycelium of Penicillium chrysogenum, on plant–pathogen interactions. Pen controlled a broad range of pathogens on several crop plants under greenhouse and field
conditions. Pen protected grapevine from downy and powdery mildew (caused by Plasmopara viticola and Uncinula necator), tomato from early blight (caused by Phytophthora infestans), onion from downy mildew (Peronospora destructor) and apple trees from apple scab (caused by Venturia inaequalis) to a similar extent as fungicides such as copper and sulphur or well-known inducers such as benzothiadiazole or β-aminobutyric
acid. Pen had no major direct fungicidal effect and is thus supposed to protect plants by activating their defense mechanisms.
The raw material for extraction of Pen was available in constant quality, a prerequisite for commercial application. Under
certain conditions, Pen caused phytotoxic side effects. The symptoms mostly consisted of small necrotic spots or, more rarely,
of larger necrotic areas. The development of the symptoms was dependent on several parameters, including concentration of
Pen, the number of applications, the persistence on the plant tissue, the plant species and variety and environmental conditions.
In grapevine, a partially purified fraction of Pen was much less toxic than the crude Pen extract, but protected the plants
to a similar extent against P. viticola. Our data show that Pen has interesting and unique properties as a plant protection agent, but more research is needed to
further reduce its phytotoxic side effects. 相似文献
15.
16.
M. C. Lobato F. P. Olivieri E. A. González Altamiranda E. A. Wolski G. R. Daleo D. O. Caldiz A. B. Andreu 《European journal of plant pathology / European Foundation for Plant Pathology》2008,122(3):349-358
Phosphites (Phi) are alkali metal salts of phosphorous acid, with the ability to protect plants against different pathogens.
In this research, the effect of Phi applied to potato plants on severity of three important potato diseases in Argentina was
assessed. Seed tubers and foliage of potato cvs Shepody and Kennebec were treated with Phi to assess effects on resistance
against Phytophthora infestans, Fusarium solani and Rhizoctonia solani. Protection resulting from Phi treatment in seed tubers was high against P. infestans, intermediate against F. solani, and low against R. solani. In addition, seed tubers treated with calcium or potassium phosphites (CaPhi and KPhi, respectively) at 1% of commercial
product emerged earlier than untreated ones. When Phi were foliarly applied two or four times at different doses, high levels
of protection against P. infestans were achieved in both cultivars. Higher protection was observed in Kennebec when CaPhi was applied, while in Shepody this
was true for KPhi. Expression of β-1,3-glucanases was induced at different times after treatment but no correlation between
β-1,3-glucanases expression and foliar protection level was found. On the other hand, Phi positive protection effects did
not produce negative effects in plant growth. Leaves from CaPhi-treated plants showed a darker green colour than leaves from
control plants; also an increase in Rubisco protein and a delay in crop senescence was observed. 相似文献
17.
Yoav Bashan Luz E. de-Bashan 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(9):821-829
Inoculation of tomato seeds with the plant growth-promoting bacterium Azospirillum brasilense, or spraying tomato foliage with A. brasilense, streptomycin sulfate, or commercial copper bactericides, separately, before or after inoculation with Pseudomonas syringae pv. tomato, the casual agent of bacterial speck of tomato, had no lasting effect on disease severity or on plant height and dry weight. Seed inoculation with A. brasilense combined with a single streptomycin foliar treatment and two foliar bactericide applications at 5-day intervals (a third or less of the recommended commercial dose) reduced disease severity in tomato seedlings by over 90% after 4 weeks, and significantly slowed disease development under mist conditions. A. brasilense did not induce significant systemic resistance against the pathogen although the level of salicylic acid increased in inoculated plants. Treatment of tomato seeds that were artificially inoculated with P. syringae pv. tomato, with a combination of mild chemo-thermal treatment, A. brasilense seed inoculation, and later, a single foliar application of a copper bactericide, nearly eliminated bacterial leaf speck even when the plants were grown under mist for 6 weeks. This study shows that a combination of otherwise ineffective disease management tactics, when applied in concert, can reduce bacterial speck intensity in tomatoes under mist conditions. 相似文献
18.
Moshe Reuveni Reuven Reuveni 《European journal of plant pathology / European Foundation for Plant Pathology》2000,106(7):633-638
A spray inoculation of the first leaf of 2-leaf stage cucumber plants with a non-pathogenic isolate of Alternaria cucumarina or Cladosporium fulvum before a challenge inoculation with the pathogen Sphaerotheca fuliginea induced systemic resistance to powdery mildew on leaves 2–5. Systemic resistance was expressed by a significant (p < 0.05) reduction in the number of powdery mildew colonies produced on each leaf of the induced plants, as compared with water-sprayed plants. Systemic resistance was evident when a prior inoculation with each of the inducing fungi was administered 1, 3 or 6 days before the challenge inoculation with S. fuliginea. Increasing the inoculum concentration of A. cucumarina or C. fulvum enhanced the systemic protection and provided up to 71.6% or 80.0% reduction, respectively, in the number of colonies produced on upper leaves, relative to controls. Increasing the inoculum concentration of S. fuliginea used for challenge inoculation, increased the number of powdery mildew colonies produced on both induced and non-induced plants. Pre-treated plants, however, were still better protected than controls, indicating that the level of systemic protection was related to the S. fuliginea inoculum concentration. The induction of systemic resistance against powdery mildew by biotic agents, facilitates the development of a wide range of disease management tools. 相似文献
19.
枯草芽胞杆菌HMB-20428与化学杀菌剂互作对葡萄霜霉病菌抑制作用和替代部分化学药剂减量用药应用 总被引：1，自引：0，他引：1
为明确生防菌剂枯草芽胞杆菌Bacillus subtilis HMB-20428与化学杀菌剂互作对葡萄霜霉病菌Plasmopara viticola的抑制作用,采用生物测定与田间药效试验研究其最佳用药时期,筛选最佳生化互作组合,结合空间竞争能力和诱导抗病性生理测定试验了解互作增效机制,并建立葡萄霜霉病的综合防控技术。结果显示,枯草芽胞杆菌HMB-20428预防葡萄霜霉病最佳时期为发病前1个月,连续喷雾用药3~4次,间隔期10~15 d。研发出协同增效生化互作组合生防菌剂HMB-20428+嘧菌酯,及其与硅氧烷化合物增效组合,防效分别为91.06%~98.92%和87.78%~92.04%。枯草芽胞杆菌HMB-20428与嘧菌酯互作可增强枯草芽胞杆菌HMB-20428定殖能力和植株抗病作用,且定殖能力和抗病机制作用的增强时间基本一致。以生防菌剂HMB-20428替代部分化学药剂减量用药流程的防效为91.40%。表明枯草芽胞杆菌HMB-20428与嘧菌酯互作可达到减少化学药剂用量的目的。 相似文献
20.
Abstract The evaluation of greenhouse and field screening methods for the identification of resistance to bacterial blight (Xanthomonas vignicola Burkh.) amongst germplasm and breeding lines of cowpea (Vigna unguiculata(L.) Walp.) is described. A stem injection technique and a leaf infiltration method were found reliable under greenhouse conditions while foliar spray inoculation was appropriate for use in both greenhouse and field experiments. A seed inoculation technique for evaluating seedling mortality may prove useful although only one susceptible cowpea accession was used in this study. Since distinct syndromes of bacterial blight (seedling mortality, stem canker and foliar blight) are recognised, it may be advantageous to adopt a different inoculation method for each syndrome to establish the relationship between the resistance of different plant parts within cowpea genotypes. Results confirm the existence of at least two distinct mechanisms of resistance to bacterial blight in cowpea. Hypersensitive resistance was clearly demonstrated in the accession TVu 410 by the leaf injection infiltration method; VITA 3 was shown to possess a field resistance, expressed as reduced and delayed disease development. The probable stability of these mechanisms is discussed with regard to their suitability as breeding objectives. 相似文献