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1.
The fungicides metiram, mancozeb, metiram + triphenyltin hydroxide, propamocarb hydrochloride + chlorothalonil, dimethomorph + mancozeb, cymoxanil + mancozeb, and chlorothalonil were applied by aircraft and through center-pivot irrigation systems (chemigation) to replicated plots in commercial fields of ‘Russet Burbank’ potato. Fungicide deposition and redistribution were indirectly determined by inoculation of excised leaves withPhytophthora infestans and directly by chlorothalonil residue analysis from upper, middle, and lower crop canopies. The effectiveness of two surfactants added with fungicide and applied by aircraft, an increased water volume rate used by aircraft, and a reduced water volume used with chemigation was also determined. The addition of synthetic latex and siliconepolyether surfactants did not increase efficacy of metiram or mancozeb in controlling late blight when applied by aircraft. The protectant fungicides metiram, mancozeb, and chlorothalonil were not significantly different from dimethomorph + mancozeb, cymoxanil + mancozeb, and propamocarb hydrochloride + chlorothalonil in late blight control when applied by aircraft. However, cymoxanil + mancozeb had limited efficacy when applied by chemigation. Fungicide deposition through the canopy differed when air applications were made before or after canopy closure (row closure). Fungicides applied by aircraft prior to row closure protected the entire canopy; whereas, fungicide application after row closure initially protected the top and middle canopies, and subsequent applications and redistribution of the fungicides were needed for adequate protection throughout the canopy. The fungicides and fungicide mixtures tested were evenly deposited throughout the potato canopy with each chemigation application. Severity of late blight did not differ on leaves treated with mancozeb or chlorothalonil applied by aircraft at water volumes of 47 L/ha and 94 I/ha and then inoculated withP. infestans, nor did severity of late blight differ on inoculated leaves previously treated with chlorothalonil by chemigation at water volumes of 15,145 and 50, 571 L/ha. 相似文献
2.
Strategies based on using the translaminar fungicide cymoxanil for control of potato late blight, caused by Phytophthora infestans, were compared in the highland tropics of Ecuador in three separate field experiments. In one strategy, a commercial formulation of cymoxanil mixed with mancozeb was sprayed sequentially three times early in the season; this was then followed by three sequential sprays of a commercial product containing mancozeb alone. For the other strategy, the same commercial products were alternated. For each strategy, a spray interval of 14 d was used after the contact/translaminar mixture and 10 d after sprays containing mancozeb alone. Both strategies were evaluated with a manually operated knapsack sprayer but with two levels of application quality. High quality was achieved with a constant pressure valve and a new nozzle, while for low quality, fungicide was applied without a valve and using a damaged nozzle. All treatment combinations gave adequate disease control and no consistent effect of application strategy or application quality could be measured on disease severity or yield. However, approximately twice the volume of fungicide was applied using poor quality equipment, regardless of the application strategy. Advantages and disadvantages of the strategies and their potential effects on fungicide resistance are discussed. 相似文献
3.
Uptake and translocation of the fungicide cymoxanil was studied using tomato and potato plants infected with Phytophthora infestans and grape plants infected with Plasmopara viticola. Translocation of cymoxanil was mainly translaminar and acropetal from roots and stems to leaves to an extent similar to that of the phenylamide fungicide oxadixyl. Basipetal translocation from upper to lower leaves, as well as lateral movement, was also observed but to a lesser extent. Plant parts that grew after application were protected against P. infestans and P. viticola because of systemic activity up to 7 days by cymoxanil alone and up to 14 days when cymoxanil was used as part of a three-way mixture with oxadixyl and mancozeb. Drench application of cymoxanil and a simultaneous spray application of mancozeb against P. infestans and P. viticola resulted in a significant synergistic interaction. The spray application of the three-way mixture oxadixyl/mancozeb/cymoxanil was more effective against both sensitive and phenylamide-resistant strains of P. infestans and P. viticola than the individual components alone, representing significant levels of synergistic interactions. Synergy ratios were higher for resistant than for sensitive strains of both pathogens. 相似文献
4.
《Crop Protection》1988,7(3):210-215
Field-grown potatoes (cv. Alpha) were sprayed with fungicides at the commercially recommended rates 0–15 days before being inoculated with a phenylamide-resistant isolate of Phytophthora infestans (Mont.) DeBary. Numbers of lesions, or disease severity, in fungicide-treated versus fungicide-free plants were used to calculate the percentage control efficacy of fungicides over time. Efficacy over time fitted a declining logistic model in 26 out of 31 cases. Non-transformed data showed a significantly longer duration of > 90% efficacy of the cymoxanil mixtures Mancur (mancozeb + cymoxanil, 4 + 1), Pulsan (mancozeb + oxadixyl + cymoxanil, 7 + 1 + 0 · 4) and Sandocur-M (mancozeb + oxadixyl + cymoxanil, 7+1+2) (9–11 days) compared with SAN-518 (mancozeb + oxadixyl, 7+1), Ridomil-MZ (mancozeb + metalaxyl, 1 + 7 · 5), mancozeb or Curzate (4–6 days). Predicted T50 values (number of days with >50% efficacy) were significantly larger for Pulsan and Sandocur-M (16 days) than for Ridomil-MZ (11 days), SAN-518 (10 days), mancozeb (9 · 5 days) and Curzate (7 · 5 days). Numeric integration of the area under the predicted control efficacy curves gave significantly larger values for Pulsan and Sandocur-M compared with the other fungicides except Mancur. Linear regression of logit disease control values over time resulted in the smallest slope for Sandocur-M. Analysis of variance showed no significant interaction between fungicide and cumulative rain. We predict that Pulsan and Sandocur-M may effectively control phenylamide-resistant Phytophthora infestans in the field at 14-day spray intervals, and Mancur at 10-day intervals. 相似文献
5.
《Crop Protection》1987,6(1):64-71
Three fungicides with different modes of action—oxadixyl (phenylamide; systemic), mancozeb (dithiocarbamate; protectant), and cymoxanil (penetrant)—were tested alone and in different combinations against Plasmopara viticola on grapes and Phytophthora infestans on tomatoes. The fungicidal activities against sensitive and phenylamide-resistant strains were compared. The fungicidal activity of the mixture oxadixyl/mancozeb decreased significantly with increasing levels of resistance, whereas the mixture oxadixyl/mancozeb/cymoxanil was almost equally active against all strains. The level of synergistic interaction of fungicide mixtures was found to be dependent on the proportion of the single components in the mixture as well as on the activity of the individual compounds against the fungal strains. Cymoxanil-containing mixtures showed equally high or even higher levels of synergism against resistant compared with sensitive strains, whereas in oxadixyl/mancozeb mixtures synergism was lower in resistant situations. The methods used are suitable for finding those combinations of fungicides which give rise to maximum synergistic interactions: this was achieved with the uses of isobolograms, which were adapted to three-component mixtures leading to three-dimensional figures. 相似文献
6.
H. T. A. M. Schepers 《Potato Research》1996,39(4):541-550
Summary The influence of the intensity of rain and the interval between application of fungicides and the onset of rain on the efficacy
of maneb-fentinacetate and fluazinam againstPhytophthora infestans in potato was evaluated in pot trials and field trials. In the pot trials a clear wash-off of maneb-fentinacetate was observed
when simulated rain was applied 4 hours after plants had been sprayed with the fungicide. The retention of fluazinam deposits
was higher and in some trials the efficacy in the bioassay was even increased by rain, probably by redistribution from the
spray deposits. When 10 mm of simulated rain was applied 4–6 days after application of the fungicides, no decrease in the
efficacy was observed with both fungicides. In the field trials fluazinam also showed a better retention of deposits compared
with maneb-fentinacetate. 相似文献
7.
Summary Final disease ratings, apparent infection rates and areas under disease progress curves were used to calculate lower fungicide
rates for potato cultivars with high levels of polygenic resistance toPhytophthora infestans. Areas under disease progress curves offered more reliable indications than final disease ratings or apparent infection rates.
Control of epidemic development was achieved using 20–80% of the recommended application rates of mancozeb on plots of cvs
Brodick. Cara and Torridon compared with full application rates on cv. Maris Piper. 相似文献
8.
Philip B. Hamm Tom F. Cummings Dennis A. Johnson 《American Journal of Potato Research》2006,83(6):473-484
Fungicides are applied by air, chemigation, and ground in the Columbia Basin of Oregon and Washington. These methods of fungicide application differ in deposition of fungicide to the canopy and cost. This study compared the alternate use of air and chemigation application of fungicides (AIRCHEM) with chemigation alone (CHEM), by either measuring chlorothalonil or manganese (mancozeb) amounts in three canopy levels (upper, middle, lower), both on leaflets and stems, after multiple fungicide applications on a 7-day schedule. Greater amounts of chlorothalonil or mancozeb were usually found on the leaflets in the upper and middle canopy locations from AIRCHEM compared to CHEM, the day of fungicide application and 7 days later. Deposition of fungicides on stems generally follow the same pattern as leaflets, but the amount deposited and maintained on stems was significantly less than leaflets. Mancozeb deposition in the three canopy levels followed the same pattern as was found for chlorothalonil. The greater the amounts of chlorothalonil on leaflets and stems resulted in better disease reduction during inoculation assays. Reduced fungicide amounts on stems compared to leaflets may be the reason for increased stems infections in recent years by more aggressive strains of late blight. This is the first report quantifying chlorothalonil or mancozeb amounts on potato stems and the first to report amounts of mancozeb on potato foliage after fungicide application. 相似文献
9.
Isolates ofPhytophthora infestans collected in Canada from potato and tomato plants from 1994 to 1998 were tested for their responsein vitro to equal active ingredient concentrations (1, 2.5, and 5 μg a.i/mL) of six commercial fungicides: Acrobat MZ (dimethomorph and mancozeb), Ridomil Gold (metalaxyl-m), Dithane (mancozeb), Curzate (cymoxanil), Bravo (chlorothalonil), and Tattoo C (propamocarb and chlorothalonil). Relative mycelial growth of isolates estimated on fungicideamended vs fungicide-free media was compared among isolates of the US-8 and US-11 genotypes from the two host plants. The effects of these fungicides on spore germination of isolates from the two genotypes were also estimated. Mycelial growth of US-8 and US-11 isolates was most affected by Bravo and Tattoo C, followed by Acrobat, and then Curzate and Dithane. Ridomil Gold was not effective in inhibitingin vitro growth of US-11 isolates at the concentrations tested. Variations in sensitivity to different fungicides among isolates of the same genotype collected in different years were observed. For example, based on 2.5 and 5 μg a.i./mL, potato/US-11 isolates collected from 1995 to 1997 showed increased sensitivity to Curzate and Ridomil Gold, while decreased sensitivity was recorded with Dithane. For US-8 isolates, responses to the fungicides varied according to fungicide and year. Variations were generally not significant for Acrobat, Curzate, Bravo, and Tattoo C over time. Conversely, potato/US-8 isolates from 1995 and 1998 were less sensitive to Dithane and Ridomil Gold than those from 1994, 1996, and 1997. 相似文献
10.
试验采用生长速率法测定了双炔酰菌胺、恶酮.霜脲氰、氟菌.霜霉威、烯酰.松脂酮、丙森锌.霜脲氰、代森锰锌6种杀菌剂对马铃薯晚疫病菌的毒力。结果表明,供试6种杀菌剂对马铃薯晚疫病菌丝生长都有良好的抑制效果。双炔酰菌胺的毒力最强,其EC50值为0.029μg/mL,恶酮.霜脲氰、丙森锌.霜脲氰、烯酰.松脂酮、氟菌.霜霉威毒力依次减弱,而代森锰锌毒力最差,其EC50值为5.502μg/mL。根据室内毒力测定结果及药剂特性,供试的6种杀菌剂在田间防治上可视病害的发生情况交替或混合应用,做到科学合理搭配,以避免或延缓抗药性的产生。 相似文献
11.
12.
The efficacy of ten fungicides against Mycosphaerella nawae, the causal agent of circular leaf spot (CLS) of persimmon, was evaluated in vitro and in field experiments. Field trials were conducted in 2009 and 2010 to investigate the comparative efficacy of the fungicides alone or combined using alternating sequences in spray programmes based on two, three or four applications. Disease incidence was assessed by estimating the percentage of affected leaves, which included leaves showing at least one necrotic spot and defoliation. Fenpropimorph, pyraclostrobin, tebuconazole and thiophanate-methyl were the most effective fungicides in inhibiting mycelial growth of M. nawae isolates (EC50 < 2 ppm). In field experiments, the most effective fungicides using two spray applications were captan, chlorothalonil, mancozeb and pyraclostrobin which significantly reduced disease incidence compared with untreated plots. Regarding the number of spray applications, two applications of captan and mancozeb were less efficient than three to control the disease. However, the percentage of affected leaves provided by three applications of captan and mancozeb alone or combined with pyraclostrobin using alternating sequences in spray programmes, was not significantly different from that provided by four applications. Experimental results demonstrated that spray programmes based on three applications of these fungicides could effectively control CLS of persimmon. The advantages of spray programmes based on alternated use of strobilurins and protective fungicides are discussed. 相似文献
13.
Summary Phenylamide-based fungicides were reintroduced to the Irish market in 1985. Mixtures of phenylamides and mancozeb were recommended
for no more than 3 sprays in potato late blight control programmes with the last systemic spray to be applied not later than
31 July. Samples of potato foliage infected withP. infestans were collected from the main potato growing areas in Ireland over a five-year period starting in 1985. Using the floating
disc method, 11% of the crops sampled in 1985 were found to have phenylamide-resistant strains ofP. infestans present. The number of crops with resistant strains increased rapidly up to 1988 when 83% of the crops sampled had resistance.
Factors affecting the distribution of resistance and the efficacy of a phenylamide-based spray programme are discussed. 相似文献
14.
九种杀菌剂对Fusarium verticillioides和F.graminearum毒力及玉米穗腐病的防治效果 总被引：1，自引：1，他引：0
采用含毒介质法分别测定玉米穗腐病菌禾谷镰孢菌和拟轮枝镰孢菌对9种药剂的敏感性,在田间进行防治玉米穗腐病的药效试验,综合评价化学和生物药剂以及不同施药处理对玉米穗腐病的防治效果。室内毒力测定结果表明,9种药剂在一定浓度下对玉米穗腐病均有毒力作用,10%苯醚甲环唑、70%甲基托布津对禾谷镰孢菌毒力较强;70%甲基托布津对轮枝镰刀菌毒力较强,10%苯醚甲环唑次之。田间药效试验结果表明,50%异菌脲可湿性粉剂防效为92.3%,5%井冈霉素为80.64%;且先接菌后喷药的防治效果优于先喷药后接菌处理。 相似文献
15.
Wani AA Rewal HS Sahoo S Singh B Bhat JA 《Pakistan journal of biological sciences: PJBS》2012,15(1):44-48
The persistence of fungicides on two commercial cultivars of potato was determined under field conditions at Punjab Agricultural University, Ludhiana, Punjab. Initial deposits of mancozeb on potato leaves were found to be 26.9 and 38.7 mg kg(-1), following application of ready mixture of fungicide metalaxyl 8% + mancozeb 64% (Ridomil MZ) at the rate of 1260 and 2520 g a.i. ha(-1), whereas metalaxyl residues were found to be 35.1 and 49.5 mg kg(-1), respectively. The residue level of mancozeb in potato leaves 15 days after application at single and double doze were 19.0 and 27.0 mg kg(-1) showing a loss of 29.6 and 30.3%, whereas the values for metalaxyl at single and double doze were 0.40 and 0.80 mg kg(-1) showing a loss of 98.9 and 98.4%, respectively. Residues of mancozeb and metalaxyl were not detected at 0.04 and 0.02 mg kg(-1) level in potato tubers at harvest (PHI = 53 days) at both the dosages, respectively. The persistence and dissipation of mancozeb with the application of Ridomil MZ followed similar trend as in Indofil M-45. The rate of fungicide dissipation increased with time after application in both the potato cultivars 'Kufri Chandramukhi' and 'Chipsona'. No significant difference was observed on initial deposit, persistence and dissipation of the two molecules between the two potato cultivars. 相似文献
16.
Summary Field experiments between 1996 and 2000 compared the efficacy of fungicide programmes applied in accordance with the NegFry
and Met éireann (Mé) decision support systems (DSS) for the control of late blight with 7- and 10-day routine fungicide programmes.
The Mé DSS reduced fungicide use by 68% and 54% respectively while NegFry reduced fungicide use by 49% and 27% compared with
the 7- and 10-day programmes. The NegFry DSS was similar to the 10-day routine programme in terms of late blight control,
quality and marketable yield. A similar result was found when the NegFry DSS was compared with a 7-day routine mancozeb programme
(included for two seasons only). Within the NegFry DSS the use of fluazinam resulted in improved yield, foliage blight and
tuber blight control compared with mancozeb, but this benefit was significant for tuber blight only. The Mé DSS resulted in
inferior disease control, yield and quality. 相似文献
17.
18.
Laetitia Marais 《Potato Research》1990,33(2):275-281
Summary Thirty three fungicides were evaluatedin vitro andin vivo for the control of anthracnose, caused byColletotrichum coccodes (Wallr.) Hughes. Three promising fungicides, thiram, captafol wp and sc and prochloraz, were identified by a filter paper-disc
plate method, but only prochloraz had an effect when using a fungicide plate method. None of the fungicides adequately controlled
anthracnosein vivo. 相似文献
19.
马铃薯晚疫病是马铃薯生产中的重要病害,是影响马铃薯产量和品质的重要因素之一,在云南春作马铃薯上普遍发生,且危害较重,给当地马铃薯产业带来了巨大的经济损失。为减轻马铃薯晚疫病对马铃薯生产造成的损失,试验研究了11种药剂7种药剂组合(包衣剂+保护剂+治疗剂)通过播种期种薯包衣,现蕾期叶面喷施一次保护剂,发病初期和发病中期叶面各喷一次治疗剂的方法防治马铃薯晚疫病。结果表明,药剂组合种薯包衣+甲霜·锰锌+氟吡菌胺·霜霉威的防治效果最好,防治效果达到60.99%,增产率176.28%,增效率152.27%;其次是种薯包衣+霜脲·锰锌+氟吡菌胺·霜霉威组合,防治效果达到60.15%,增产率173.20%,增效率150.55%。这2个药剂组合对马铃薯晚疫病均有极显著的防治效果,增产增效明显。 相似文献
20.
P.D. Roberts M.T. Momol L. Ritchie S.M. Olson J.B. Jones B. Balogh 《Crop Protection》2008,27(12):1519-1526
Bacterial spot caused by Xanthomonas euvesicatoria Jones et al. and Xanthomonas perforans Jones et al. is a major disease on fresh market commercial tomato in Florida. Fourteen field trials were conducted between 1999 and 2005 (10 in south Florida and four in north Florida) testing famoxadone plus cymoxanil (Tanos 50DF®, E.I. du Pont de Nemours and Company, Wilmington, DE), Bacillus subtilis strain QST 713 (B. subtilis) (Serenade WPO® or Serenade Max®, AgraQuest, Inc., Davis, CA), and acibenzolar-S-methyl (ASM) (Actigard 50WG®, Syngenta Crop Protection, Greensboro, NC) at different rates and in various application programs that were combined and rotated with copper hydroxide and mancozeb for management of bacterial spot. In field applied spray treatments containing famoxadone as a component, all of the programs significantly reduced bacterial spot severity on plants compared to the untreated control plants (UTC) and 97% of the programs were equal for disease suppression conferred by the copper-mancozeb standard. In spray programs containing ASM or B. subtilis plus copper hydroxide, treated plants had significantly reduced disease compared to the UTC plants and were not different from the plants treated with the copper-mancozeb standard. Yield data from small plots was unaffected. Several of the programs which used these compounds in rotation with copper-mancozeb provided similar levels of reduction in the disease severity for bacterial spot while reducing by 50% the amount of copper applied to plants. The effect of famoxadone plus cymoxanil on the survival of Xanthomonas in vitro did not cause a significant reduction in the bacterial population and was not determined to be directly bactericidal. However, greenhouse and field testing supports disease reduction of bacterial spot on plants treated with these compounds. The products tested in these trials may be useful, alternative tools for use in an integrated management program for bacterial spot on tomato. 相似文献