scholarly journals Fluazinam: A New Fungicide for Control of Sclerotinia Blight and Other Soilborne Pathogens of Peanut1

1992 ◽  
Vol 19 (2) ◽  
pp. 115-120 ◽  
Author(s):  
F. D. Smith ◽  
P. M. Phipps ◽  
R. J. Stipes
Keyword(s):  
Disease Incidence ◽  
Effective Means ◽  
Sclerotium Rolfsii ◽  
Field Trials ◽  
Effective Control ◽  
Cercospora Arachidicola ◽  
Advisory Program ◽  
Sclerotinia Blight ◽  
Better Than

Abstract Fluazinam provided effective control of Sclerotinia blight (Sclerotinia minor Jagger) of peanut in six field trials during a 4-yr period. Applications of fluazinam (0.56 kg/ha) at the onset of Sclerotinia blight and 4 wk later provided an average of 69% suppression of disease incidence and increased yields by 1598 kg/ha compared to untreated plots. Performance of fluazinam was significantly better than iprodione, the material currently used for control of Sclerotinia blight. Two applications of iprodione at 1.12 kg/ha provided only 31% suppression of disease incidence and increased yield by 718 kg/ha. Fungicides were also evaluated in 1990 as tank-mixes with chlorothalonil (1.26 kg/ha) that were applied in foliar sprays according to the Virginia peanut leafspot advisory program. Treatments consisted of no fungicide, chlorothalonil alone, and tank-mixes of chlorothalonil plus either dicloran at 2.10 kg/ha, fluazinam at 0.56 kg/ha, or iprodione at 0.84 kg/ha. Sclerotinia blight at harvest in untreated plots and plots treated with chlorothalonil alone averaged 27.8 and 35.8 disease foci per plot, whereas yields averaged 3624 and 2251 kg/ha, respectively. Compared to plots treated with chlorothalonil alone, Sclerotinia blight was suppressed by 92, 25, and 25%, and yield was increased by 4020, 1925, and 1684 kg/ha in plots treated with chlorothalonil plus either fluazinam, iprodione, or dicloran, respectively. Applications of tank-mixes containing fluazinam plus chlorothalonil in 1991 provided additional evidence that this approach was a highly effective means of controlling both Sclerotinia blight and early leafspot, a previously unattainable goal. Fluazinam did not control early leafspot (Cercospora arachidicola S. Hori) in field trials; however, the fungicide was fungitoxic in vitro to Sclerotium rolfsii Sacc. and Rhizoctonia solani Kühn.

scholarly journals Characterization of Antagonistic Bacillus methylotrophicus Isolated From Rhizosphere and Its Biocontrol Effects on Maize Stalk Rot

2019 ◽  
Vol 109 (4) ◽  
pp. 571-581 ◽  
Author(s):  
Xingkai Cheng ◽  
Xiaoxue Ji ◽  
Yanzhen Ge ◽  
Jingjing Li ◽  
Wenzhe Qi ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Disease Incidence ◽  
Field Trials ◽  
Control Measures ◽  
Disease Suppression ◽  
Effective Control ◽  
Stalk Rot ◽  
Bacillus Methylotrophicus ◽  
Transmission Electron ◽  
Potential Biocontrol Agent

Stalk rot is one of the most serious and widespread diseases in maize, and effective control measures are currently lacking. Therefore, this study aimed to develop a new biological agent to manage this disease. An antagonistic bacterial strain, TA-1, was isolated from rhizosphere soil and identified as Bacillus methylotrophicus based on morphological and biochemical characterization and 16S ribosomal RNA and gyrB gene sequence analyses. TA-1 exhibited a strong antifungal effect on the growth of Fusarium graminearum mycelium, with 86.3% inhibition at a concentration of 108 CFU per ml. Transmission electron microscopy showed that TA-1 could disrupt the cellular structure of the fungus, induce necrosis, and degrade the cell wall. Greenhouse and field trials were performed to evaluate the biocontrol efficacy of TA-1 on maize stalk rot, and the results of greenhouse experiment revealed that the bacterium significantly reduced disease incidence and disease index. Seeds treated with a 108 CFU ml−1 cell suspension had the highest disease suppression at 86.8%. Results of field trials show that seed bacterization with TA-1 could not only reduce maize stalk rot incidence but also increase maize height, stem diameter, and grain yield. The lipopeptide antibiotics were isolated from the culture supernatants of TA-1 and identified as surfactins and iturins. Consequently, B. methylotrophicus TA-1 is a potential biocontrol agent against maize stalk rot.

scholarly journals Night Spraying Peanut Fungicides I. Extended Fungicide Residual and Integrated Disease Management

Plant Disease ◽  
2010 ◽  
Vol 94 (6) ◽  
pp. 676-682 ◽  
Author(s):  
J. Augusto ◽  
T. B. Brenneman ◽  
A. K. Culbreath ◽  
P. Sumner
Keyword(s):  
Disease Management ◽  
Chemical Control ◽  
Sclerotium Rolfsii ◽  
Residual Activity ◽  
Field Trials ◽  
Stem Rot ◽  
Integrated Disease Management ◽  
Cercospora Arachidicola ◽  
Puccinia Arachidis ◽  
Fungicide Efficacy

The efficacy of chemical control of stem rot (caused by Sclerotium rolfsii) of peanut (Arachis hypogaea) relies partially on increasing deposition and residual activity in the lower canopy. Tebuconazole (0.21 kg a.i./ha, four applications) and azoxystrobin (0.31 kg a.i./ha, two applications) were each applied on peanut plants in daylight or at night, when leaves were folded, in two Tifton, GA, field trials in 2007. Both timings of each fungicide provided similar control of early leaf spot (caused by Cercospora arachidicola). Night applications of azoxystrobin and tebuconazole reduced stem rot at digging and increased yield compared with day applications. Night applications of tebuconazole were also tested in Nicaragua from 2005 to 2007. Peanut plants had less stem rot, similar levels of rust (caused by Puccinia arachidis), and higher yield with night applications than with day applications. Residual activity of azoxystrobin and tebuconazole were improved on the bottom shaded leaves (on which fungicides would be better deposited with night application) compared with top, sun-exposed leaves (where most fungicide would be deposited with a day application) according to a bioassay with S. rolfsii. Increased fungicide residual activity within the bottom canopy may increase fungicide efficacy on stem rot and augment peanut yield.

Effects of root inoculation and fungicide soil drenches on sclerotinia blight of coneflower

2000 ◽  
Vol 80 (4) ◽  
pp. 909-915 ◽  
Author(s):  
H. Wang ◽  
K. F. Chang ◽  
S. F. Hwang ◽  
G. D. Turnbull ◽  
R. J. Howard
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Dose Response ◽  
Root Rot ◽  
Field Experiments ◽  
Disease Incidence ◽  
Response Model ◽  
Inoculum Sources ◽  
Sclerotinia Blight ◽  
Seedling Roots

Greenhouse studies showed that root inoculation had significant effects on sclerotinia blight (Sclerotinia sclerotiorum) of coneflower (Echinacea sp.). Seedling wilt and root rot symptoms caused by S. sclerotiorum were most severe when inoculum was placed in direct contact with seedling roots, and diminished as the distance of the inoculum from the roots increased. When colonized agar disks, colonized oat grains and sclerotia as inoculum sources were evaluated on E. angustifolia, grain inoculum was the most virulent and sclerotia the least. An in vitro bioassay was conducted, and a logistic dose-response model was developed for the fungicides benomyl, vinclozolin, iprodione and dicloran. The first three fungicides were further evaluated in greenhouse experiments. Benomyl was the most effective in controlling S. sclerotiorum in both bioassay and greenhouse evaluations. The same three fungicides were evaluated in two field experiments in Alberta, where all were effective in reducing disease incidence. Key words: Echinacea sp., Sclerotinia sclerotiorum, dose-response model

Evaluation of Ammonium Bicarbonate for Control of Soilborne Peanut Pathogens

1990 ◽  
Vol 17 (1) ◽  
pp. 28-31 ◽  
Author(s):  
T. B. Brenneman ◽  
A. S. Csinos ◽  
P. M. Phipps
Keyword(s):  
Rhizoctonia Solani ◽  
Mycelial Growth ◽  
Sclerotium Rolfsii ◽  
Foliar Spray ◽  
Ammonium Bicarbonate ◽  
In Vitro Studies ◽  
Stem Rot ◽  
Pod Yield ◽  
Sclerotinia Blight

Abstract Ammonium bicarbonate was evaluated for efficacy against southern stem rot and Sclerotinia blight of peanut in Georgia and Virginia, respectively. In vitro studies indicated the material provided little inhibition of mycelial growth by Sclerotinia minor and Sclerotium rolfsii, and negligible inhibition of mycelial growth of Rhizoctonia solani AG-4. However, ammonium bicarbonate did effectively inhibit formation of sclerotia by S. rolfsii in vitro. In the field, it was phytotoxic when applied as a granule or as a foliar spray and in general was not effective in controlling disease or increasing pod yield.

scholarly journals Potential Bacterial Antagonists for the Control of Charcoal Rot (Macrophomina phaseolina) in Strawberry

Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 457
Author(s):  
Josefina Viejobueno ◽  
Natalia Rodríguez-Berbel ◽  
Luis Miranda ◽  
Berta de los Santos ◽  
María Camacho
Keyword(s):  
Disease Incidence ◽  
Hydrolytic Enzymes ◽  
Macrophomina Phaseolina ◽  
Field Trials ◽  
Dry Mass ◽  
Dual Culture ◽  
Plant Mortality ◽  
Charcoal Rot ◽  
Rdna Sequencing

The effect of antagonistic bacteria to control Macrophomina phaseolina was evaluated under in vitro, growth chamber, greenhouse and field conditions. A total of 177 bacteria, isolated from Athrocaulon macrostachyum rhizosphere of the Lebrija marsh, were screened for their potential against M. phaseolina (causes charcoal rot in strawberry) by dual culture assay. Of these isolates, 14 most promising strains were molecularly identified by the 16S rDNA sequencing method using the EzBioCloud database. These strains were tested for in vitro hydrolytic enzymes, HCN production, and biocontrol against M. phaseolina in strawberry plants. All the 14 strains produced, at least, one hydrolytic enzymatic activity and one of them, which belongs to Brevibacterium genus (Hvs8), showed the lowest records of disease incidence (20%) and severity (0.4). With these results, greenhouse and field trials were carried out with the Hvs8 strain, compared to non-treated control. In the greenhouse assays, Hvs8 strain increased root dry mass by 30%, over the control. In the field trials, production and fruit quality were not significantly different between Hvs8 treatment and non-treated control, but plant mortality and plant mortality associated to M. phaseolina decreased by more than 24% and 65% respectively, in Hvs8 treatment. This study suggests that Brevibacterium sp. Hvs8 strain could be a candidate for controlling charcoal rot in strawberry.

scholarly journals Use of Trichoderma in Biological Control of Collar Rot of Soybean and Chickpea

2020 ◽  
pp. 25-31
Author(s):  
Mahbuba Kaniz Hasna ◽  
Md. Abul Kashem ◽  
Farid Ahmed
Keyword(s):  
Seed Treatment ◽  
Field Experiments ◽  
Disease Incidence ◽  
Sclerotium Rolfsii ◽  
Antagonistic Activity ◽  
Root Weight ◽  
Dual Culture ◽  
Collar Rot ◽  
Rot Disease

An in vitro and field experiments for two consecutive years were conducted at Bangladesh Institute of Nuclear Agriculture, Mymensingh, aiming to investigate the efficacy of Trichoderma harzianum against Sclerotium rolfsii causing collar rot disease of soybean and chickpea. In in vitro the antagonistic activity of T. harzianum against S. rolfsii was observed through dual culture. In field experiment Trichoderma was applied as soil treatment and seed treatment. The percent inhibition of S. rolfsii induced by T. harzianum was found upto 78.9% in in vitro. The maximum reduction of collar rot disease incidence over control was 82.4% in soybean and 77.6% in chickpea which was recorded in the plot where T. harzianum was applied in the soil. The highest seed germination: 86.3% in soybean and 84.8% in chickpea, maximum fresh shoot weight: 94.5 g plant-1 in soybean, 62.5 g plant-1 in chickpea, maximum fresh root weight: 10.7 g plant-1 in soybean, 9.3 g plant-1 in chickpea and the highest yield: 2830 kg ha-1 in soybean, 1836 kg ha-1 in chickpea were obtained by the application of Trichoderma in soil. The study indicated that the tested isolate of T. harzianum had potential in controlling collar rot disease of soybean and chickpea. For the reduction of collar rot incidence application of T. harzianum in soil was found more effective than seed treatment. 

scholarly journals Salts Application for Suppressing Potato Early Blight Disease

2009 ◽  
Vol 49 (4) ◽  
pp. 353-361 ◽  
Author(s):  
Nehal El-Mougy ◽  
Mokhtar Abdel-Kader
Keyword(s):  
Sodium Bicarbonate ◽  
Calcium Chloride ◽  
Early Blight ◽  
Disease Incidence ◽  
Pathogenic Fungus ◽  
Fungal Growth ◽  
Plant Diseases ◽  
Effective Control ◽  
Blight Disease

Salts Application for Suppressing Potato Early Blight DiseaseThe suppressive effect of sodium and calcium salts applied individually or combined with the yeastSaccharomyces cerevisiaeagainstAlternaria solanithe causal agent of early blight disease of potato was evaluated under laboratory, greenhouse and field conditions.In vitrotest a complete inhibition in fungal growth was observed at concentration of 30 mg/ml of both sodium bicarbonate and calcium chloride. The commercial backing yeastS. cerevisiae(CBY) enhanced the inhibitory effect of tested salts reflected in increasing mycelial fungal growth reduction when combined at the rate of 1:1 at each concentration tested. In pot experiment, under artificial infestation with pathogenic fungus, application of sodium bicarbonate or calcium chloride significantly reduced the early blight incidence and severity by increasing their concentrations. Their most effective concentration were 30 mg/ml that reduced the disease incidence by 50 and 62.4%, respectively. Superior effect of sodium bicarbonate or calcium chloride in disease reduction was observed when they combined with CBY. Field trails for evaluating the most promising greenhouse treatments were preformed under natural infestations during two successive summer seasons. Calcium chloride proved higher efficacy for reducing both disease incidence and severity than that of sodium bicarbonate when applied either alone or combined with CBY. Also, it is observed that increasing concentrations of both sodium bicarbonate or calcium chloride showed parallel decrease in disease incidence and severity. Application of (CBY) enhanced the efficacy of salts spraying against early blight disease. Similar trend was also observed with the increase of potato tubers yield. On the light of the present study it could be suggested that the usage of combined application of the yeastS. cerevisiaewith sodium bicarbonate or calcium chloride might be used as easily applied, safely and cost effective control methods against such plant diseases.

Transmission dynamics and control options for Echinococcus granulosus

Parasitology ◽  
2003 ◽  
Vol 127 (S1) ◽  
pp. S143-S158 ◽  
Author(s):  
P. R. TORGERSON ◽  
D. D. HEATH
Keyword(s):  
Echinococcus Granulosus ◽  
Disease Incidence ◽  
Effective Means ◽  
Public Health Problem ◽  
Control Measures ◽  
Transmission Dynamics ◽  
Effective Control ◽  
Global Public Health ◽  
Persistent Problem ◽  
Economic Output

Cystic echinococcosis, caused by the larval stage of Echinococcus granulosus, is a global public health problem. Whilst in a few localities, such as New Zealand, the parasite has been effectively controlled or even eradicated, in most endemic regions it remains a persistent problem. In some areas, such as the former Soviet Union, the disease incidence in humans has increased rapidly in recent years. It is important to have an understanding of the transmission dynamics, both between dogs and domestic livestock where the parasite maintains itself and from dogs to people. It is from this knowledge that effective control measures can be devised to reduce the prevalence of the parasite in animals and hence reduce the incidence of human disease. Mathematical models to describe the transmission of the parasite and the effects of different control strategies were first proposed over twenty years ago. Since then further information has been acquired, new technology has been developed and better computing technology has become available. In this review, we summarise these developments and put together a theoretical framework on the interpretation of surveillance information, how this affects transmission and how this information can be exploited to develop new intervention strategies for the control of the parasite. In particular, the parasite remains a persistent or re-emerging problem in countries of low economic output where resources for an intensive control programme, that has been successful in rich countries, are not available. By understanding of the transmission biology, including mathematical modelling, alternative and cost-effective means of control can be developed.

scholarly journals Development of a Weather-Based Advisory Program for Scheduling Fungicide Applications for Control of White Rust of Spinach

Plant Disease ◽  
2003 ◽  
Vol 87 (8) ◽  
pp. 923-928 ◽  
Author(s):  
M. J. Sullivan ◽  
J. P. Damicone ◽  
M. E. Payton
Keyword(s):  
Spinacia Oleracea ◽  
Disease Incidence ◽  
Field Trials ◽  
Control Treatment ◽  
Systemic Fungicide ◽  
Advisory Programs ◽  
Advisory Program ◽  
White Rust ◽  
Control Disease ◽  
Day Program

Weather-based advisory programs were developed and evaluated for timing of fungicide applications to control white rust of spinach (Spinacia oleracea) in three field trials using a susceptible cultivar. The advisory programs were based on previous studies that defined periods of temperature (T) and wetness (relative humidity ≥90%, W) that favored disease development. The protectant fungicides mancozeb or maneb (ethylene bisdithiocarbamates; EBDCs) and the systemic fungicide azoxystrobin were applied after 3, 6, 12, 24, and 36 cumulative hours of wetness weighted by temperature (T*W). T*W programs were compared with an advisory program based on 12 h of continuous wetness (12-h W), a 7-day calendar program, and a nonsprayed control treatment. Except for the 3-h T*W program, the number of fungicide applications per trial was reduced for all advisory programs compared with the 7-day program. Averaged over the three trials, applications were reduced from 2.7 per trial for the 6-h T*W program to 3.7 per trial for the 36-h T*W and the 12-h W programs. For the EBDC fungicides, all advisory programs except the 36-h T*W and 12-h W programs reduced incidence and severity of white rust compared with the nonsprayed control. Disease incidence and severity for the 3-h and 6-h T*W programs did not differ from the 7-day program. Compared with the EBDC fungicides, azoxystrobin resulted in reduced disease incidence for each of the spray programs and reduced disease severity for all spray programs except the 7-day program. For azoxystrobin, all advisory programs reduced disease incidence and severity compared with the nonsprayed control. Incidence and severity of white rust did not differ from the 7-day program for the 3-h, 6-h, and 12-h T*W programs. Based on reductions in the number of fungicide applications and the level of disease control, the 6-h and 12-h T*W programs were most efficient advisory programs for the EBDC fungicides and azoxystrobin, respectively.

scholarly journals Effect of Some Essential Oils for Limiting Early Blight (Alternaria Solani) Development in Potato Field

2009 ◽  
Vol 49 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Nehal El-Mougy
Keyword(s):  
Essential Oils ◽  
Early Blight ◽  
Disease Incidence ◽  
Foliar Spray ◽  
Fungal Growth ◽  
Alternaria Solani ◽  
Plant Diseases ◽  
Effective Control ◽  
Potato Field

Effect of Some Essential Oils for Limiting Early Blight (Alternaria Solani) Development in Potato FieldThe fungicidal effect of some essential oils againstAlternaria solanione of the species that cause early blight of potato was evaluated underin vitroand field conditions. Effect of carnation, caraway, thyme oils and the chemical fungicide Ridomil MZ 72 at various concentrations on mycelial growth ofA. solaniwas tested. Carnation oil had the strongest and most extensive inhibitory effect on fungal growth. Slightly less effective were caraway and thyme oils followed by the chemical fungicide. Extended field trails for two cultivation seasons proved that the application of essential oils twice as foliar spray had a superior effect to the fungicide treatment for reducing the early blight incidence comparing with untreated control. An opposite relationship between the disease incidence and concentrations of applied essential oils was observed. The increase in potato yield also followed the same trend. The highest reduction in disease incidence and yield increase was recorded in treatments with 1% of carnation, caraway and thyme oils in descending order. Ridomil MZ 72 applied at the dose recommended by manufactories had a low effect in this regard. Essential oils treatments might be used as easily applied, safe and cost effective control methods against such plant diseases.

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