scholarly journals Research Regarding the Simultaneous Control of the Pathogens on Tomatoes Crops under High Plastic Tunnels

Author(s):  
Gabriela ŞOVĂREL ◽  
Marcel COSTACHE ◽  
Ana Emilia CENUŞĂ

In Romania the most important pathogens on tomatoes crops are Alternaria porri f.sp. solani, Botrytis cinerea, Fulvia fulva, Phytophthora infestans and Erysiphe sp. During period of vegetation, the attack of mentioned pathogens are frequently overlapping. For simultaneously control of pathogenswere used some combination with different active substances (chlorothalonil 500g/l, iprodione 500 g/l, fenhexamid 500 g/l, thiophanate methyl 500g/l, metiram 80%, dimethomorph 9%, mancozeb 60%, difenoconazole 250 g/l , fenamidone 75g/l, propamocarb HCL 375 g/l. The best results for controlling Alternaria porri f.sp. solani, Botrytis cinerea and Fulvia fulva are metiram 80% 0.2% + thiophanate methyl 500g/l 0.14% with 93.5% efficacy. In the untreated check the degree of attack was 78.6% (44.3% A.solani, 7.0% B.cinerea and 27.3% F. Fulva). For controlling Phytophthora infestans, Erysiphe sp. and Fulvia fulva (fenamidone 75g/l + propamocarb HCL 375 g/l)    0.2% +  difenoconazole 250 g/l 0.05% with 94.5% efficacy. In the untreated check the degree of attack is 81.2% (38.4% P. infestans, 27.4% Erysiphe sp. , 15.4% F. fulva).

Plant Disease ◽  
1999 ◽  
Vol 83 (6) ◽  
pp. 569-575 ◽  
Author(s):  
L. F. Yourman ◽  
S. N. Jeffers

In 1996 and 1997, 325 isolates of Botrytis cinerea were collected from 35 commercial greenhouses growing ornamental crops in South Carolina to determine the incidence of resistance to benzimidazole and dicarboximide fungicides. Conidium germination was assessed on a defined agar medium amended with either thiophanate-methyl (a benzimidazole) or vinclozolin (a di-carboximide). A total of 53 representative isolates were evaluated further for conidium germination and mycelium growth on fungicide-amended medium and for infection of geranium seedlings treated with thiophanate-methyl or vinclozolin at label rates. Isolates were considered sensitive to thiophanate-methyl or vinclozolin when the effective concentration of the fungicide active ingredient resulting in 50% inhibition of germination (EC50-germ) was ≤5 μg/ml or when the effective concentration of fungicide active ingredient resulting in 50% inhibition of mycelium growth (EC50-growth) was ≤1 μg/ml. Of all isolates, 81% (262/325) were resistant to thiophanate-methyl and 69% (223/325) were resistant to vinclozolin. Four phenotypes were observed: sensitive to both fungicides (17%), resistant to both fungicides (67%), resistant only to thiophanate-methyl (14%), and resistant only to vinclozolin (2%). Isolates resistant to at least one fungicide were found in 33 of the 35 locations from which samples were taken. Disease incidences on geranium seedlings treated with 600 μg/ml of thiophanate-methyl and then inoculated with isolates sensitive and resistant to this fungicide were 1.4 and 96.1%, respectively. Disease incidences on geranium seedlings treated with 600 μg/ml of vinclozolin and then inoculated with isolates sensitive and resistant to this fungicide were 0.3 and 91.9%, respectively. With thiophanate-methyl, correlation coefficients (r) between disease incidence and log EC50-germ or log EC50-growth were 0.987 and 0.992, respectively. With vinclozolin, correlation coefficients between disease incidence and log EC50-germ and log EC50-growth were 0.975 and 0.893, respectively. Correlation coefficients between the two EC50 values for thiophanate-methyl were 0.989 and for vinclozolin were 0.900. Isolates sensitive to thiophanate-methyl had a mean EC50-germ value of 0.93 μg/ml and a EC50-growth value of 0.11 μg/ml. For isolates sensitive to vinclozolin the mean EC50-germ value was 1.63 μg/ml and the mean EC50-growth value was 0.26 μg/ml. Thiophanate-methyl-resistant isolates had mean EC50-germ and EC50-growth values greater than 500 μg/ml while vinclozolin-resistant isolates had a mean EC50-germ value greater than 500 μg/ml and a mean EC50-growth value of 3.18 μg/ml.


Irriga ◽  
2006 ◽  
Vol 11 (3) ◽  
pp. 328-338
Author(s):  
Ieoschua Katz ◽  
Antonio Ribeiro da Cunha ◽  
Antonio De Pádua Sousa ◽  
Egberto Egon de Herdani

COMPARAÇÃO DE DOIS MÉTODOS DE APLICAÇÃO DE FUNGICIDAS,IRRIGAÇÃO POR GOTEJAMENTO  E PULVERIZAÇÃO CONVENCIONAL    NO CONTROLE DO MOFO CINZENTO (Botrytis cinerea Pers.: Fr.) EM VASOS COM PLANTAS DE LISIANTHUS (Eustoma grandiflorum (Raf.) Shinn.)  Ieoschua Katz1; Antonio Ribeiro da Cunha2; Antônio de Pádua Sousa1; Egberto Egon de Herdani11Departamento de Engenharia Rural, Faculdade de Ciëncias Agronömicas, Universidade Estadual Paulista, Botucatu, SP, [email protected] Departamento de Recursos Naturais, , Faculdade de Ciëncias Agronömicas, Universidade Estadual Paulista, Botucatu, SP  1 RESUMO Novas técnicas de combate às doenças têm sido usadas, como os defensivos hidrossolúveis via água de irrigação, a quimigação, um procedimento recente que reduz a mão de obra, com uniformidade na aplicação, menor contato do operador com produtos tóxicos, e menores impacto ambiental e custo de produção. Visando o controle do mofo cinzento (Botrytis cinerea) na cultura do Lisianthus, este trabalho teve o intuito de avaliar dois métodos de aplicação de fungicidas, a aplicação via gotejamento (fungigação) e a pulverização, com diferentes tratamentos. Os fungicidas utilizados foram: thiofanato metílico (50 g i.a. L-1), thiofanato metílico + chlorothalonil (50 g i.a. L-1 + 35 g i.a. L-1) e iprodione (50 g i.a. L-1). Avaliou-se o número de lesões, o número de botões florais e a altura das plantas de Lisianthus. Foi possível concluir que, tanto na fase de crescimento (número de lesões na planta) como na fase final (número de botões florais) da cultura de Lisianthus, os tratamentos 2 (thiofanato metílico + chlorotalonil) e 3 (iprodione) foram os mais eficientes. Considerando que o tratamento 2 é uma mistura de dois fungicidas, o primeiro sistêmico e o segundo de contato, independente das vias de aplicação, a mistura aumentou a eficiência em relação ao tratamento 1 (thiofanato metílico). Com isso, a aplicação por gotejamento (fungigação), revelou eficiência equivalente à técnica de pulverização. UNITERMOS: Lisianthus, quimigação, irrigação por gotejamento, controle de doenças .  KATZ , I.; CUNHA, A. R. da; SOUSA, A. de P.; HERDANI, E.E.de. COMPARISON OF TWO METHODS OF FUNGICIDE APPLICATION, DRIP IRRIGATION AND CONVENTIONAL SPRAYING CONTROL FOR CINEREOUS MILDEW (Cinerea botrytis Pers.:Fr.) IN POTTED PLANTS OF LISIANTHUS (Eustoma grandiflorum (Raf.) Shinn.)  2 ABSTRACTPlant disease control techniques are used through the irrigation water, which reduces the labor and it improves application uniformity with smaller contact of the operator with toxic products, lower environmental impact and lower production cost. In order to control Botrytis cinerea the Lisianthus culture, this work aimed to evaluate two fungicide application methods with different treatments. The fungicides were: thiophanate methyl (50 gi.a. L-1), thiophanate methyl + chlorothalonil (50 g i.a. L-1 + 35 g i.a. L-1) and iprodione (50 g i.a. L-1). Number of lesions, number of diseased floral buttons and height of the Lisianthus plants were evaluated. It was possible to deduce, that in the growth stage (number of lesions in the plant) as well as in the final stage (number of floral buttons) of the Lisianthus culture, the most efficient treatments were 2 (thiophanate methyl + chlorothalonil) and 3 (iprodione). Considering that treatment 2 is a mixture of two fungicides, a systemic and a contact one, independently of application methods, the mixture increased efficiency in relation to treatment 1 (thiophanate methyl). Thus, chemigation was as efficient as spreading technique. KEYWORDS: Lisianthus, chemigation, drip irrigation, disease control


Plant Disease ◽  
2020 ◽  
Vol 104 (4) ◽  
pp. 1069-1075
Author(s):  
Hervé F. Avenot ◽  
David P. Morgan ◽  
Joel Quattrini ◽  
Themis J. Michailides

In this study, a mycelial growth assay was used to evaluate the sensitivity to thiophanate-methyl of 144 Botrytis cinerea isolates (collection A) from Californian vineyards and pistachio and pomegranate orchards. Based on the effective concentration that inhibits 50% of growth (EC50) values for mycelial growth inhibition on fungicide-amended media, 3, 28, 10, and 58% of the isolates showed sensitivity (SS; EC50 < 1 µg/ml), low resistance (LR; 1 < EC50 < 10 µg/ml), weak resistance (WR; 10 < EC50 < 50 µg/ml), and high resistance (HR; EC50 > 100 µg/ml) toward thiophanate-methyl, respectively. The LR and HR phenotypes were observed in pistachio and pomegranate orchards, even though pomegranate was not sprayed with thiophanate-methyl. Sensitivity to thiophanate-methyl of a historical collection of 257 B. cinerea isolates (collection B) isolated from pistachio orchards in 1992, 2005, and 2006 was assessed on potato dextrose agar amended with thiophanate-methyl at the discriminatory concentration of 10 µg/ml. Average percentages of thiophanate-methyl–resistant isolates were 50, 72, and 64% in the orchards in 1992, 2005, and 2006, respectively. A study of fitness components of selected thiophanate-methyl–resistant (LR, WR, and HR) and –sensitive (SS) isolates from collection A did not reveal any significant difference between them with respect to mycelial growth on fungicide-free media and pathogenicity on cultivar Crimson Seedless berries. Comparison of β-tubulin sequences from resistant and sensitive phenotypes revealed that a glutamic acid at position 198 was changed to alanine in all HR isolates and three LR isolates. The occurrence of thiophanate-methyl resistance in B. cinerea populations should be considered when designing spray programs against blossom and shoot blight of pistachio and gray mold of grape.


Plant Disease ◽  
1997 ◽  
Vol 81 (7) ◽  
pp. 729-732 ◽  
Author(s):  
J. A. LaMondia ◽  
S. M. Douglas

Botrytis cinerea was isolated from infected plants in six greenhouses in Connecticut. Forty-five isolates were evaluated in vitro to determine fungicide sensitivity to benzimidazole (benomyl and thiophanate-methyl) and dicarboximide fungicides (vinclozolin and iprodione). B. cinerea isolates with fungicide resistance were recovered from each greenhouse sampled. Benzimida-zole resistance was more common than dicarboximide resistance (74 to 76% versus 36 to 43%, respectively). Multiple fungicide resistance was common. Nineteen isolates were resistant to both a benzimidazole and a dicarboximide fungicide. The level (EC50) of resistance to dicer-boximides was low compared with resistance to benzimidazoles. Isolate growth rate was not correlated to fungicide sensitivity or EC50. Fungicide resistance was apparently unrelated to the patterns of fungicide use in greenhouses sampled.


Plant Disease ◽  
2014 ◽  
Vol 98 (6) ◽  
pp. 825-833 ◽  
Author(s):  
Dolores Fernández-Ortuño ◽  
Anja Grabke ◽  
Patricia Karen Bryson ◽  
Achour Amiri ◽  
Natália A. Peres ◽  
...  

The sensitivity to seven chemical classes of fungicides was investigated in 1,810 Botrytis cinerea isolates collected from strawberry blossoms and fruit in 181 strawberry fields from seven southern states in the United States across 2 years. Ten isolates were examined from each field. Fungicide sensitivity assays were carried out based on visual assessment of diametrical mycelial growth after 4 days of incubation on media amended with discriminatory doses of fungicides in microtiter plates. Results of visual assessments were verified with selected isolates using a previously published germination assay and by inoculating representative isolates with resistant phenotypes on fungicide-sprayed fruit. The overall resistance frequencies of 750 isolates collected in 2012 for thiophanate-methyl, pyraclostrobin, boscalid, cyprodinil, fenhexamid, iprodione, and fludioxonil were 76, 42, 29, 27, 25, 3, and 1%, respectively. Frequencies of 1,060 isolates collected in 2013 were 85, 59, 5, 17, 26, 2, and 1%, respectively. Resistance to thiophanate-methyl and pyraclostrobin was found in virtually every location in both years, whereas resistance to iprodione and fludioxonil was rarely found. Resistant isolates were resistant to either one (23%), two (18%), three (19%), four (14%), five (3%), or six (0.1%) chemical classes of fungicides in 2012. In 2013, this distribution was 24, 29, 26, 8, 2, and 0.3%, respectively. Multifungicide-resistant isolates of B. cinerea were widespread in southern states and evidence suggests that the frequency of isolates with multifungicide resistance increased from 2012 to 2013. The data also show that fungicide resistance in B. cinerea was already present in blossoms, indicating that resistance management needs to be implemented early in the season.


2020 ◽  
Vol 1 (1) ◽  
pp. 31-36
Author(s):  
Gabriela Şovărel ◽  
Simona-Ştefania Hogea ◽  
Ana-Emilia Cenuşă ◽  
Marcel Costache

The experiment was carried out in 2020, under high plastic tunnels conditions, using the tomato hybrid Prekos F1 and aimed to evaluate the efficacy of different combinations of fungicides with insecticides for complex control of pathogens Alternaria solani (early blight), Fulvia fulva (leaf mold) and pests Tuta absoluta (tomato leaf miner) and Helicoverpa armigera (cotton bollworm). The experimental variants were: 1. Cabrio Top 0.2% + Coragen 0.0175%; 2. Cabrio Top 0.2% + Voliam Targo 0.08%; 3. Dagonis 0.1% + Coragen 0.0175%; 4. Dagonis 0.1% + Voliam Targo 0.08%; 5. Cidely Top 0.1% + Coragen 0.0175%; 6. Cidely Top 0.1% + Voliam Targo 0.08%; 7. Ortiva Top 0.1% + Coragen 0.0175%; 8. Ortiva Top 0.1% + Voliam Targo 0.08%; 9. Untreated control. Six foliar treatments were applied at 10- days intervals. The efficacy of these combinations of fungicides with insecticides was assessed according to the degree of attack (%) for Alternaria solani, Fulvia fulva and Tuta absoluta or according to the frequency of the attacked fruits (%) for Helicoverpa armigera and was between 85.0% and 90.7%. The highest yields were registered in variants 1 (Cabrio Top 0.2% + Coragen 0.0175% - 5,535 kg/m2), 3 (Dagonis 0.1% + Coragen 0.0175% - 5,440 kg/m2) and 2 (Cabrio Top 0.2% + Voliam Targo 0.08% - 5,362 kg/m2) as compared to 4,490 kg/m2 in the untreated control variant. The differences of yield, obtained in addition to the untreated control variant, were very significant in all cases.


Plant Disease ◽  
2014 ◽  
Vol 98 (6) ◽  
pp. 851-851 ◽  
Author(s):  
A. Amiri ◽  
A. I. Zuniga ◽  
J. Mertely ◽  
N. A. Peres

Botryotinia fuckeliana de Bary (anamorph Botrytis cinerea Pers.) is an ubiquitous plant pathogen causing gray mold disease on more than 200 crops grown in the field or in greenhouses. Eucalyptus seedlings originating from three different greenhouses showing stem lesions were submitted to the Gulf Coast Research and Education Center Disease Clinic in June 2012. Ten single spore isolates of B. cinerea were obtained and tested for sensitivity using spore germination and germ tube elongation assays described previously (4). Fungicides tested were pyraclostrobin at 100 μg/ml (Cabrio, BASF, Research Triangle Park, NC), thiophanate-methyl at 100 μg/ml (Topsin-M, UPI, King of Prussia, PA), fenhexamid at 1 and 50 μg/ml (Elevate, Arysta Life Sciences, Cary, NC), fludioxonil at 0.1 and 10 μg/ml (Medallion, Syngenta Crop Protection, Research Triangle Park, NC), and iprodione at 5 and 50 μg/ml (Rovral, Bayer CropScience, Greensboro, NC) on 1% malt extract agar (MEA, 10 g malt extract and 15 g agar), and to cyprodinil at 1 and 25 μg/ml (Vanguard, Syngenta Crop Protection) on 0.5% sucrose agar (4). Sensitivity to the succinate dehydrogenase inhibitors (SDHIs) boscalid at 5 μg/ml (Endura, BASF), penthiopyrad at 1 and 3 μg/ml (Fontelis, DuPont Crop Protection, Willington, DE), and fluopyram at 3 μg/ml (Luna Privilege, Bayer CropScience) was evaluated on yeast bacto acetate agar (YBA) (3). The discriminatory dose for boscalid was adapted from (2) whereas those used for penthiopyrad and fluopyram were developed in this study. Isolates were grown on malt yeast extract agar for 7 to 10 days and spore suspensions were prepared in sterile distilled water and diluted to 106 conidia/ml. Respective media in 9-cm petri dishes were seeded with 7-μl droplets from each isolate allowing testing for all isolates on one plate. Two plates were used for each fungicide and sensitivity tests were repeated twice. Germination and germ tube growth were assessed microscopically after 16 to 24 h incubation at 22°C. The frequency of isolates resistant to two, three, and four fungicides was 90, 60, and 10%, respectively. Nine isolates (90%) were resistant to thiophanate-methyl and pyraclostrobin, simultaneously, whereas six (60%) and two isolates (20%) were resistant to boscalid and fenhexamid, respectively. All boscalid-resistant isolates were also resistant to pyraclostrobin and thiophanate-methyl, but one fenhexamid-resistant isolate was sensitive to the other three fungicides. Eight isolates that germinated at 5 μg/ml iprodione but not at 50 μg/ml were considered sensitive. All isolates were sensitive to the SDHIs penthiopyrad and fluopyram as well as to cyprodinil and fludioxonil. To our knowledge, this is the first report of resistance to pyraclostrobin, thiophanate-methyl, fenhexamid, and boscalid in B. cinerea from eucalyptus seedlings in Florida. The absence of resistance to fludioxonil and iprodione is likely because these fungicides are not registered in nurseries as well as fluopyram and penthiopyrad which were developed only recently. Management practices should be developed to limit the selection and spread of additional resistant populations in eucalyptus nurseries as has occurred in Florida strawberries where multi-fungicide resistance is widespread (1). References: (1) A. Amiri et al. Plant Dis. 97:393, 2013. (2) M. Leroch et al. Appl. Environ. Microbiol. 79:159, 2013. (3) G. Stammler and J. Speakman. J. Phytopathol. 154:508, 2006. (4) R. W. S. Weber and M. Hahn. J. Plant Dis. Prot. 118:17, 2011.


Plant Disease ◽  
2011 ◽  
Vol 95 (10) ◽  
pp. 1263-1269 ◽  
Author(s):  
Roland W. S. Weber

During the vegetation period 2010, 353 isolates of Botrytis cinerea from 23 Northern German strawberry, raspberry, highbush blueberry, and redcurrant fields were examined for sensitivity to the benzimidazole derivative thiophanate-methyl and the dicarboximide iprodione, as well as five fungicides currently used against gray mold in Germany. Of all isolates, 40.5% were highly resistant to thiophanate-methyl, 64.0% to iprodione, 45.0% to fenhexamid, 76.8% to trifloxystrobin, 21.5% to boscalid, and 14.7% to cyprodinil. No high resistance to fludioxonil was observed but medium resistance was recorded to fludioxonil as well as cyprodinil (41.1 and 27.2% of all isolates, respectively). In all, 63 isolates were sensitive to all five of the currently registered botryticides whereas 43, 81, 94, 49, and 23 isolates were medium or highly resistant to one, two, three, four, and five fungicides, respectively. Isolates resistant to five fungicides in vitro were capable of causing fruit rot on wounded apple pretreated with any one of the three commercially available products containing fenhexamid, pyraclostrobin plus boscalid, or cyprodinil plus fludioxonil. These results question the sustainability of the current gray mold control strategy relying exclusively on fungicides with specific, single-site modes of action.


Plant Disease ◽  
2018 ◽  
Vol 102 (9) ◽  
pp. 1803-1810 ◽  
Author(s):  
Juliana S. Baggio ◽  
Natalia A. Peres ◽  
Lilian Amorim

Botrytis fruit rot, caused by Botrytis cinerea, is one of the most important strawberry diseases worldwide, and fungicide applications are often used to manage the disease in commercial production. Isolates of B. cinerea were collected from conventional and organic strawberry fields in four Brazilian States from 2013 to 2015 and their sensitivity to the main single-site mode-of action fungicides used in Brazil was tested. Resistance to azoxystrobin, iprodione, pyrimethanil, and thiophanate-methyl was found and values for effective concentration that inhibited mycelial growth by 50% were higher than 71.9, 1.2, 5.0, and 688 µg/ml, respectively, regardless the production system. Resistance to these fungicides was observed in 87.5, 76.6, 23.4, and 92.2% of isolates from conventional fields and 31.4, 22.9, 14.3, and 51.4% of isolates from organic fields, respectively. Moreover, frequencies of isolates with multiple fungicide resistance to the four active ingredients were 20.6 and 2.8% whereas 6.3 and 27.8% were sensitive to the four fungicides for conventional and organic areas, respectively. Molecular analyses of the cytochrome b, β-tubulin, and bos1 genes revealed the presence of G143A; E198A; and I365 N/S, Q369P, or N373S mutations, respectively, in resistant isolates of B. cinerea. Field rates of fungicides sprayed preventively to inoculated strawberry fruit failed to control disease caused by the respective resistant isolates.


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