Application Of Mancozeb Research Articles

Fungicides and Bioagents Are Used to Manage Downy Mildew on Pearl Millet

Pennisetum glaucum (L.), pearl millet Known by most as bajra, it is a significant warm-season grain that is mostly farmed in India under rainfed circumstances. In India, downy mildew caused by Sclerospora graminicola (Sacc.) Schroet is the most common and deadly disease affecting pearl millet. Two weeks after seeding, the illness was visible as chlorotic stripes on the leaf surface advanced from the base to the top. Most infected plants were unable to develop typical, healthy earheads. The bioagents that were examined as seed dressers were Trichoderma harzianum (6 g/kg seed), Pseudomonas fluorescens (8 g/kg seed), Trichoderma viride (6 g/kg seed), and neem oil and water. The downy mildew disease incidence was significantly reduced (2.83%) by the fungicides Mancozeb at 0.2%, Neem oil, Metalaxyl at 0.25%, and Carbendazim at 0.25%, as compared to the control, which had a documented disease incidence of 40.33%. Neem oil considerably outperformed all evaluated bioagent seed dressings for downy mildew prevention, including the seed dressing containing Pseudomonas fluorescens seed treatment at 8 g/kg seed was statistically comparable to Trichoderma harzianum seed treatment at 6 g/kg seed and Metalaxyl application at 0.25%. The downy mildew was also greatly reduced by foliar application of Mancozeb at 0.2 % and seed treatment with Metalaxyl (6 g/kg seed) + spray of Propiconazole at 25% EC at 0.25%; these two methods outperformed the seed dressing with all evaluated bioagents. The positive outcome of using neem oil topically suggests that, when it comes to managing downy mildew in pearl millet in an environmentally benign manner, it might replace fungicides.

Fungicide evaluation against head smudge (Curvularia spp.) and its impact on yield and germination of tef (Eragrostis tef Zucc.)

Head smudge, caused by Curvularia spp., is the major disease of tef in the humid tef-growing areas of Ethiopia. Despite this, farmers continue producing tef without any disease management strategies, which is leading to substantial quantitative and qualitative losses. Hence, the field and laboratory experiments were conducted to assess the efficacy of seven fungicides for the management of head smudge and simultaneously to assess the possible effects of the disease on seed quality of tef. The field experiment was conducted at Dangila and North Achefer districts and the treatments were arranged in a randomized complete block design with three replications. Tef seeds harvested from field experiments were subsequently used for laboratory studies using the blotter method and arranged in a completely randomized design. The effect of fungicides on reducing disease incidence and severity and increasing yield was significant (p < 0.001). The highest overall mean disease control (88.9%) was obtained from propiconazole sprayed plots followed by trifloxystrobin + tebuconazole and tebuconazole, both of which had a similar 85.5% disease reduction. The applications of triadimefon resulted in intermediate disease reduction (69.9%). However, the application of mancozeb + cymoxanil, cymoxanil + copper oxychloride, and thiamethoxam + metalaxyl + difenoconazole doesn’t bring a significant improvement from the untreated plot. According to our findings, head smudge can reduce tef yield by up to 62% and germination by 18.7 to 45.4%. Therefore, the application of propiconazole, trifloxystrobin + tebuconazole, and tebuconazole can be considered as effective head smudge management practice until other management options are developed.

Mancozeb associated with water deficit: Physiological and biochemical responses of soybean plants

Can oxidative stress from xenobiotics be intensified under water deficit conditions? Based on the hypothesis that the exposure to a xenobiotic aggravates the oxidative damages induced by water deficit, soybean plants were cultivated in pots eqquipped with soil water potential sensors to continuously monitor soil moisture levels. The experiment was conducted in 2020, in a protected environment, using a randomized block design with three replications. To comprehensively evaluate physiological and biochemical responses of plants, we conducted a range of analyses, including measurements of stomatal conductance, leaf temperature, chlorophyll, chlorophyll fluorescence, relative water content, membrane damage, electrical conductivity, lipid peroxidation, concentration of reactive oxygen species – hydrogen peroxide and superoxide, activity of antioxidative enzymes – ascorbate peroxidase, superoxide dismutase, catalase, non-enzymatic compounds – non protein thiols, nitric oxide and proline. Plants that received the application of the fungicide mancozeb showed 1 °C higher temperature compared to the control plants. Irrigated soybean plants had higher nitric oxide content when treated with mancozeb, but under water deficit the higher content was observed in control plants. No deleterious effects of mancozeb as a xenobiotic were observed when applied at the recommended dose for soybean cultivation, even under water deficit conditions. The plants exhibited deleterious effects caused by water deficit, particularly in relation to oxidative stress induced by water shortage. The combination of two stresses (water deficit and xenobiotics) did not result in the maximization of negative effects caused by water stress. By refuting the working hypothesis, it becomes evident that the application of mancozeb to plants under water deficit conditions did not exacerbate the damage induced by this stress. Responses to this combination are contingent upon various factors, including the stress duration, its severity, the plant species involved, and, in the case of xenobiotics, their inherent properties and mode of action within the plant.

Self-reported and urinary biomarker-based measures of exposure to glyphosate and mancozeb and sleep problems among smallholder farmers in Uganda

ObjectiveWe aim to showcase the impact of applying eight different self-reported and urinary biomarker-based exposure measures for glyphosate and mancozeb on the association with sleep problems in a study among 253 smallholder farmers in Uganda. MethodsThe questionnaire-based exposure measures included: (1) the number of application days of any pesticide in the last 7 days (never, 1–2; >2 days) and six glyphosate and mancozeb-specific measures: (2) application status over the last 12 months (yes/no), (3) recent application status (never, last 7 days and last 12 months), (4) the number of application days last 12 months, (5) average exposure-intensity scores (EIS) and (6) EIS-weighted number of application days in last 12 months. Based on 384 repeated urinary biomarker concentrations of ethylene thiourea (ETU) and glyphosate from 84 farmers, we also estimated (7) average biomarker concentrations for all 253 farmers. Also in the 84 farmers the measured pre-work and post-work biomarker concentrations were used (8). Multivariable logistic regression models were used to assess the association between the exposure measures and selected Medical Outcomes Study Sleep Scale (MOS-SS) indices (6-item, sleep inadequacy and snoring). ResultsWe observed positive associations between (1) any pesticide application in the last 7 days with all three MOS-SS indices. Glyphosate application in the last 7 days (3) and mancozeb application in the last 12 months (3) were associated with the 6-item sleep problem index. The estimated average urinary glyphosate concentrations showed an exposure–response association with the 6-item sleep problem index and sleep inadequacy in the same direction as based on self-reported glyphosate application in the last 7 days. In the analysis with the subset of 84 farmers, both measured and modelled post-work urinary glyphosate concentration showed an association with snoring. ConclusionsSelf-reported, estimated average biomarker concentrations and measured urinary biomarker exposure measures of glyphosate and mancozeb showed similar exposure–response associations with sleep outcomes.

In Vitro Evaluation on Resistance of Phytopythium vexans (NG Isolate) Cultured from Sublethal Concentration against Several Fungicides

Phytopythium vexans isolated from potatoes rhizospher in Ngablak, Magelang, Central Java was reported having a potency to cause potato tuber rot in in vitro test. Some fungicides had been intensively applied in this area to control potato late blight even using sublethal dose. This study investigated resistance response of the pathogen against several fungicides which were Mancozeb, Dimethomorph, mixture of Mancozeb and Mefenoxam, and mixture of Oxathiapiprolin and Famoxadone. The experiment was conducted to observe the sensitivity response of pathogen against those fungicide and the experiment repeated with one of the isolates which growth in sublethal concentration to observe the resistance response. Both experiment data was analyzed by Probit Analysis. On sentivity test, data showed that P. vexans were insensitive against Dimethomorph, but it was sensitive against Mancozeb, mixture of Mancozeb and Mefenoxam, as well as mixture of Oxathiapiprolin and Famoxadone. On Mancozeb treatment, mycelia were inhibited 100% at the sugested concentration. However, at the sublethal concentration the mycelial collony grew abnormally. Pathogen isolate from the sublethal concentration were used as material for the resistance response study. The effect of the sublethal application of Mancozeb to P. vexans caused resistance to Mancozeb itself and cross resistance against Dimetomorph and mixture of Oxathiapiprolin and Famoxadone. It was proven by higher value of predicted EC50 and EC95 on the second experiment compared to the predicted EC50 and EC95 from the first one. The resistant P. vexans isolate was able to produce sporangium and chlamydospore.

Control of Bacterial Wilt (Ralstonia solanacearum) and Reduction of Ginger Yield Loss through Integrated Management Methods in Southwestern Ethiopia

Background: Bacterial wilt incited by Ralstonia solanacearum is the most important disease affecting ginger production in southwestern Ethiopia. The unavailability of disease-free planting materials, resistant cultivars, and effective chemical compounds are the key constraints in managing the disease. Objective: The study was initiated to determine the effect of integrated management methods on bacterial wilt disease and yield loss of ginger through combining hot water, bio-fumigation, soil-solarization and chemical pesticides. Methods: A total of seven treatment combinations comprising hot water, bio-fumigation, soil-solarization, Mancozeb, and bleaching powder were tested in a randomized complete block design in three replications. Data on disease incidence, growth, yield, and yield components were recorded from randomly selected plants. Results: The use of Mancozeb for seed socking and soil drenching combined with bio-fumigation and soil-solarization reduced the incidence of bacterial wilt by 63.3% and enhanced the rhizome yield by 66.8%. Rhizome and soil treatment using bleaching powder along with soil bio-fumigation also reduced the disease incidence by 38.9% and increased ginger yield by 61.5%. It also provided the highest (6678.7%) marginal rate of return of any treatment combination tested in the experiment. Disease incidence was highly significantly and inversely (r= -0.98**) correlated with rhizome yield. The regression slope estimated that 83.4% of ginger yield loss was associated with bacterial wilt disease. Conclusion: A combined application of Mancozeb, bio-fumigation and soil-solarization can be used to control ginger bacterial wilt. Alternatively, bleaching powder for rhizome and soil treatment in conjunction with bio-fumigation can be employed as an integrated management system against the disease.

Control of Bacterial Wilt (Ralstonia solanacearum) and Reduction of Ginger Yield Loss through Integrated Management Methods in Southwestern Ethiopia

Background: Bacterial wilt incited by Ralstonia solanacearum is the most important disease affecting ginger production in southwestern Ethiopia. Unavailability of disease-free planting materials, resistant cultivars, and effective chemical compounds are the key constraints in managing the disease. Objective: The study was initiated to determine the effect of integrated management methods on bacterial wilt disease and yield loss of ginger through combining hot water, bio-fumigation, soil-solarization and chemical pesticides. Methods: A total of seven treatment combinations comprising hot water, bio-fumigation, soil-solarization, Mancozeb, and bleaching powder were tested in a randomized complete block design in three replications. Data on disease incidence, growth, yield, and yield components were recorded from randomly selected plants. Results: The use of Mancozeb for seed socking and soil drenching combined with bio-fumigation and soil-solarization reduced the incidence of bacterial wilt by 63.3% and enhanced the rhizome yield by 66.8%. Rhizome and soil treatment using bleaching powder along with soil bio-fumigation also reduced the disease incidence by 38.9% and increased ginger yield by 61.5%. It also provided the highest (6678.7%) marginal rate of return of any treatment combination tested in the experiment. Disease incidence was highly significantly and inversely (r= -0.98**) correlated with rhizome yield. The regression slope estimated that 83.4% of ginger yield loss was associated with the bacterial wilt disease. Conclusion: A combined application of Mancozeb, bio-fumigation and soil-solarization can be used to control ginger bacterial wilt. Alternatively, bleaching powder for rhizome and soil treatment in conjunction with bio-fumigation can be employed as an integrated management system against the disease.

USING SALICYLIC ACID, FOLIC ACID AND/OR MANCOZEB IN CONTROLLING TOMATO EARLY BLIGHT BIOTIC STRESS AND THEIR EFFECTS ON GROWTH, YIELD, FRUIT QUALITY, AND STRESS-RELATED ENZYMES

Two field experiments were conducted to study the effect of foliar applications of salicylic acid (200 ppm), folic acid (100 ppm) and/or Mancozeb (50% and 100% of recommended dose) on the growth, yield, quality, enzymes activities related to stress, and disease severity% of tomato plants cv. “Fayrouz” grown under biotic stress conditions of early blight (A. solani) disease. The results showed significant effects of the applied treatments on all the studied characters with a noticeable superiority of the treatments of SA+FolA+50%Rec followed by 100%Rec­ without significant difference between them, which reflects on high mean values of growth, chlorophyll, yield, fruit quality, total phenol, and enzymes activities, in both seasons. Also, the best-applied treatments were related with the highest significant increases in leaves’ total phenol content in addition to enhancing the activity levels of POD, PPO, and CAT enzymes, which were found to significantly decrease the disease severity%, in both seasons. It could be suggested to reduce the recommended dose of mancozeb fungicide up to 50% by using 200 ppm of salicylic acid with 100 ppm of folic acid for ameliorating the deleterious effects of early blight and producing tomato safer for human consumption and eco-friendly.

Evaluation of Fungicides against Downy Mildew (Peronospora destructor Berk) of Onion (Allium cepa) in Bale Zone, South Eastern Ethiopia

Aims: To evaluate the efficacy of tested fungicides against downy mildew of onion and determine the appropriate interval of fungicides application.&#x0D; Study Design: The experiment was laid out down in randomized complete block design with three replications for each treatments.&#x0D; Place and Duration of Study: The experiment was carried out in farmers field of Aloshe village; Goba district of Bale zone in 2018/2019 during “Bona Season”.&#x0D; Methodology: Locally available onion variety and two tested fungicides (Mancozeb (Mancozeb 80 Wp) and Ridomil (Ridomil Gold MZ 68WG) were used. Locally available variety of onion was planted in a plot size of 3m x 2.4m with three replications. Each two fungicides were applied at interval of seven day, fourteen and twenty one day interval including unapplied fungicide plot as control.&#x0D; Results: The result indicated that, both fungicides (Mancozeb and Ridomil) were effectively reduces the severity level of the disease. The higher plant height(42.5cm), bulb weigh (289g), total weight of the bulbs (114Qt/ha) and lower severity (8.35%) were recorded from weekly application of Ridomil, fourteen day application of Ridomil and weekly application interval of Mancozeb. The higher marginal rate of return of 2833.45% and 1999.07% were recorded from weekly and fourteen applications of Mancozeb and Ridomil respectively.&#x0D; Conclusion: The minimum application frequency of three times of Ridomil in fourteen days and weekly interval application of Mancozeb were effective against downy mildew and profitable.

Integrated management of ginger bacterial wilt (Ralstonia solanacearum) in Southwest Ethiopia

Bacterial wilt incited by Ralstonia solanacearum is the most important disease threatening ginger production in southwestern Ethiopia. A field experiment was conducted to determine the effect of integrated management methods on bacterial wilt disease and yield of ginger. Thus, a total of seven treatment combinations comprising hot-water, bio-fumigation, soil-solarization, Mancozeb, and bleaching powder were tested in a randomized complete block design with three replications. Data on disease incidence, yield, and yield components of ginger were collected from a random sample of plants. Then, analysis of variance (ANOVA) was performed using R-studio 9.9 statistical software, and the means were compared by the least significant test. The results from ANOVA revealed that the incidence of bacterial wilt, rhizome yield, and its components were highly significantly (P < 0.001) affected by management methods. An integrated application of rhizome seed treatment (0.1 L−1) and soil drenching (0.3%) using Mancozeb, lemongrass for soil bio-fumigation at a rate of 10 t ha−1, along with solarization significantly reduced the incidence of bacterial wilt, the disease progress over time and produced the highest rhizome yield per hectare. Seed soaking and soil drenching in Mancozeb along with bio-fumigation was effective in reducing the disease, but a comparative yield advantage was gained through the application of bleaching powder as a seed treatment at 10% solution and soil amendment at a rate of 25 kg ha−1, along with bio-fumigation. Thus, a combined application of Mancozeb, bio-fumigation using lemongrass, and solarization with polyethylene plastic sheet can be applied to control ginger bacterial wilt disease. Alternatively, bleaching powder, bio-fumigation with lemongrass and solarization can also be used as an integrated management system against the disease.

Chemical Control Measures Against Patch Canker Disease in Rubber Plantations

The rubber plantation industry plays a significant role in Sri Lankan economy in terms of foreign exchange earnings. Rubber cultivations are affected by a number of economically important diseases and insect pests which lead to significant yield losses. During the recent past, an abnormal bark cracking at the collar region and oozing of latex of trees was frequently reported to the Rubber Research Institute. The disease has been identified as Patch Canker condition and the causative agent was reported as a fungal like pathogen Pythium spp. This study reviews the recommendations to treat patch canker disease in rubber plantations. The effects of the fungicides namely mancozeb 80%, mancozeb 64%+metalaxil-MZ72, carbendazim 50% ai, hexaconazole 50 ai, captan 50% WP, thiram 80% WP and copper oxychloride 50% WP were evaluated on the mycelial growth of the Pythium spp. using the poisoned food technique (PFT) in vitro. Hundred parts per million (100 ppm), 200 ppm, 600 ppm and 1,000 ppm active ingredient of each chemicals were subjected to testing. The field trials were carried out at Pussella Estate, Kuruwita Estate and Woodend Estate which were identified as the affected fields with Pythium spp. One hundred and twenty five moderately affected, ten years old rubber trees were selected out of five hundred trees of one hectare for the field tests of the chemical treatments at each estate. Four fungicides namely mancozeb 80%, carbendazim 50% ai, thiram 80% WP and thiophanate methyl 70% WP were tested in vivo, based on their behavior in vitro also to represent different chemical mode of action. In the PFT, the most suppression of mycelial growth in plates containing was from mancozeb at a concentration of 200 ppm. Carbendazim and mancozeb+metalaxil were both inhibitory to Pythium spp. in culture at concentrations ranging 400- 600 ppm. Fungicides thiram, copper oxychloride, hexaconazole and captan were not inhibitory to Pythium spp. at 600 ppm. According the field test fungicides mancozeb and carbendazim showed the highest average disease recovery index while the low average disease recovery index were recorded for fungicides thiram and thiophanate methyl. Based on in vitro and in vivo investigation the fungicides mancozeb and carbendazim were extremely effective in controlling the pathogen Pythium spp. No further cankers developed from the bark surface after the applications of mancozeb and carbendazim treatments. Treating affected trees with mancozeb or carbendazim will reduce the severity of patch canker caused by the Pythium spp.&#x0D; Keywords: Natural rubber, Patch Canker disease, Chemical controlling

Development of prediction equations for early blight leaf spot on tomato under different fungicides treatments

Field experiment was conducted during 2008-09 and 2009-10 to study the influence of different weather factors on the development of early blight on tomato caused by Alternaria solani (Ell. and Mart.) under six different fungicidal treatments and also to compare the two transformation models viz. Logit and Gompertz through which the disease progress curve move over time. Here, different prediction equationswere developed for each fungicide treatment separately through step down multiple regression analysis which showed that different meteorological factors having different influence on disease severity and these were done after Logistic and Gompertz transformation of the realized observed value of the disease severity (expressed as AUDPC).Results revealed that among the six fungicides tested Mancozeb was superior in controlling the disease severity with the lowest (AUDPC: 97.34 and 95.74) for the two experimental years respectively. Linearization of area under disease progress curve (AUDPC) following the two models (Logit and Gompit) showed that Gompit fit better than Logit for the prediction of early blight disease severity and this was confirmed by the low standard error estimate value of Gompertz. The co-efficient of determination value (R2) showed thatvariation in disease severity can be explained up to 77 percent (with an exception 85percent in case of Mancozeb application in 2009-10) in Logistic as well as 88 percent in Gompertz with combined effect of the weather variables included in the present study. Among the seven meteorological factors considered only average temperature,RH and total rainfall were found to act positively and significantly,whereas, bright sunshine hours were found to have negative significant effect on early blight disease severity on tomato. These situations were observed in both the transformation models but vary with in the treatments and with in the years.

Effect of Mancozeb Application Timing and Frequency on the Control Efficacy of Purple Seed Stain of Soybean Caused by Cercospora kikuchii

Effect of Mancozeb Application Timing and Frequency on the Control Efficacy of Purple Seed Stain of Soybean Caused by <i>Cercospora kikuchii</i>

Effects of mancozeb on citrus rhizosphere bacterial community

Multiple and consecutive application of fungicide might damage the rhizosphere bacterial community of citrus. In order to evaluated effect of mancozeb on the chemical properties of citrus-cultivated soil and the richness and diversity of rhizosphere bacterial community. The abundance response of rhizosphere bacterial groups without application or with application of 1.333 g mg−1 mancozeb for 2, 4, 6 and 8 times were investigated, and further studied the relationship between the rhizosphere bacterial community and chemical properties of citrus-cultivated soil. We found the rhizosphere bacterial composition and diversity were distinct between soil planted with citrus and without citrus, in addition, the abundance of rhizosphere-associated bacterial species in the soil planted with citrus increased significantly. Meanwhile, the chemical properties and the richness and diversity of rhizosphere bacterial community of the soil planted with citrus did not significantly change among different application frequence of mancozeb. Moreover, with the increased applying times of mancozeb, the relative abundance of Candidatus, Saccharibacteria, Parcubacteria, and Proteobacteria increased but the abundance of Nitrospirae decreased. In our one-year trial, there were less adverse effects of mancozeb on the citrus-cultivated rhizosphere by the repeated application of mancozeb. Therefore, mancozeb, as a fungicide, could be used multiple times to control citrus disease.

Effect of different fungicides on efficiency of mycorrhizal symbiosis on Salvia miltiorrhiza

Arbuscular mycorrhizal fungi provided is beneficial to Salvia miltiorrhiza for increasing yield, promoting the accumulation of active ingredients, and alleviating S. miltiorrhiza disease etc. However, the application of fungicides will affect the benefit of arbuscular mycorrhizal fungi and there is little research about it. This article study the effect of four different fungicides: carbendazim, polyoxin, methyl mopazine, and mancozeb on mycorrhiza benefit to S. miltiorrhiza by the infection intensity of arbuscular mycorrhizal fungi, the growth of S. miltiorrhiza, and the content of active ingredients. RESULTS:: showed that different fungicides had different effects. The application of mancozeb had the strongest inhibitory effect on the mycorrhizal benefit to S. miltiorrhiza. Mancozeb significantly reduced the mycorrhizal colonization and the beneficial effect of arbuscular mycorrhizal fungi on the growth and the accumulation of active components of S. miltiorrhiza. The application of polyoxin had no significant effect on mycorrhizal colonization. Instead, it had a synergistic effect with the mycorrhizal benefit to promoting the growth and accumulation of rosmarinic acid of S. miltiorrhiza. The inhibitory strengths of four fungicides are: mancozeb&gt;thiophanate methyl, carbendazim&gt;polyoxin. Therefore, we recommend applying biological fungicides polyoxin and avoid applying chemical fungicides mancozeb for disease control during mycorrhizal cultivation of S. miltiorrhiza.

Strategies for the Management of Leaf Blight Disease Caused by Alternaria alternata in Gloriosa superba (L.)

Leaf blight caused by Alternaria alternata (Fr.) Keissler is a severe disease of Gloriosa, causing severe yield loss in every part of Gloriosa growing areas of Tamil Nadu. The foliar pathogen was isolated from disease-infected leaves and proved its pathogenicity. Further, the molecular analysis of the pathogen using 18S rDNA confirmed the pathogen as Alternaria alternata. Attempts were made to explore the biocontrol agents and fungicides for the management of leaf blight incidence under field conditions. Four field trials conducted from 2014 to 2018 revealed that foliar application of talc-based formulation of Bacillus subtilis significantly reduced the leaf blight incidence and increased the seed yield under field conditions. Besides, prophylactic application of these biocontrol agents has also increased the plant growth parameters like plant height, number of flowers/plant, no. of pods/plant and number of seeds/pod. Similarly, foliar application of chlorothalonil (0.1%) and mancozeb (0.2%) was also credited to managing the leaf blight disease under field conditions.

Management strategies for Alternaria leaf blight on American ginseng

Cultivated American ginseng (Panax quinquifolius) is a perennial herb valued as a traditional Chinese medicine. The crop is commercially produced under polypropylene shade cloth, creating a climate favorable for leaf blight caused by Alternaria panax; frequent fungicide applications are required annually to protect yields of the root and seed. Our objective was to improve Alternaria leaf blight tactic by identifying effective products and application intervals using a calendar or the TOM-CAST disease forecaster. Product efficacy trials were conducted at two sites over two years and included 14 products and an untreated control. The fungicides pyraclostrobin and azoxystrobin + difenoconazole were consistently effective in limiting leaf blight compared to the untreated control. Fluxapyroxad + pyraclostrobin was also effective both years across both sites with one exception. Mancozeb, fluazinam, chlorothalonil, difenoconazole, and penthiopyrad were effective when disease pressure was not severe. Applications of pyraclostrobin or mancozeb resulted in a higher seedhead yield than the untreated control. The TOM-CAST disease forecaster, with spray thresholds of 10 or 15 disease severity values (DSVs) was tested at four field sites for each of two years and compared to fungicides applied every 7 or 10 days or not applied (untreated control). All treatments at three of the four sites limited disease severity compared to the untreated control in both years. According to the area under the disease progress curve (AUDPC) data, fungicide treatment programs in 2013 were similar and better than the untreated control. The AUDPC data from 2014 indicated that the 7-day application treatments had fewer diseased plants than the untreated control at all sites; the TOM-CAST 10 and 15 DSV treatments limited disease compared to the untreated control at three of the four sites. The TOM-CAST 10 DSV treatment yielded similarly to the 10-day treatment at one site for both fresh and dried root; the TOM-CAST 10 and 15 DSV treatment yields were similar. At a second site, fresh and dried root yields were similar for the 7-day and TOM-CAST 10 DSV treatments; 10-day and TOM-CAST 15 DSV treatments were similar. TOM-CAST 10 DSV may provide a balance between reducing fungicide applications while protecting valuable ginseng root yields.

Development and validation of a novel enzyme-linked immunosorbent assay for monitoring ethylene thiourea in soil and vegetable samples

A novel enzyme-linked immunosorbent assay (ELISA) was developed for the detection of ethylene thiourea (ETU); a metabolite of ethylenebisdithiocarbamates (EBDCs) fungicides such as mancozeb. The ELISA performed well under optimal conditions based one limit of detection (0.201 ng mL−1), sensitivity (IC50 3.71 µg mL−1), recovery (81.6–102.7%) and relative standard deviation (<12.5%). This method was used to determine ETU residues in soil and vegetables after 0, 1, 3, 5, 7 and 10 days following mancozeb application. Concentrations of ETU gradually increased in the soil up to the tenth day of application. While in tomato and potato samples, the maximum concentrations of ETU residues were reached on the third and fifth days, respectively, and then dissipated with half-lives of 1.33 and 4.33 days, respectively. The method was simple, rapid, cost-effective, environmentally friendly, and has the potential for high sample throughput.

Pseudomonas taiwanensis (MTCC11631) mediated induction of systemic resistance in Anthurium andreanum L against blight disease and visualisation of defence related secondary metabolites using confocal laser scanning microscopy

Abstract An attempt to evaluate induced systemic resistance in anthurium against blight disease caused by Xanthomonas axonopodis pv. dieffenbachiae (Xad) was studied. Plant associated Pseudomonas taiwanensis and elicitor compounds were used for plant application in greenhouse experiments to evaluate the resistance development against anthurium blight. Application of rhizobacteria P1 and P9 resulted in significant disease reduction to 80.0% and 85.0% respectively. Application of salicylic acid, mancozeb and K2HPO4 also resulted in reduction of disease at 35 days after inoculation. Elevated production of defence related enzymes, proteins and phenols were observed. Application of rhizobacteria P1 resulted in highest production of polyphenol oxidase and phenolic compounds. Production of phenylalanine ammonia lyase was maximum in mancozeb treated plants compared to other treatments. Maximum production of peroxidase enzyme was found in K2HPO4 treated plants whereas application of elicitor compound salicylic acid caused maximum production of defence related proteins compared to other treatments. Confocal microscopic studies revealed that P1 and P9 treated plant petiole showed increased auto fluorescent emissions indicating the distribution of defence related secondary metabolites and phenolic compounds as compared to control plants. Root colonization assay displayed significant results implicating that Rif+ and Cyclo+ resistant rhizobacterial isolates could successfully grow in the root tissue, establishing endophytic association within the host tissue.

Residues dnd dissipation of mancozeb 75% WP in/on onion

Supervised field trial was conducted to determine the dissipation of mancozeb (based on CS2) in/on onion and in cropped soil resulting from spray application of mancozeb 75 WP at recommended dose (1500 g a.i./ha) and double the recommended dose (3000 g a.i./ha). The initial residues of mancozeb (based on CS2) in immature onion including leaves were found to be 3.44 mg/kg and 5.89 mg/kg at recommended dose and double the recommended dose, respectively. Mancozeb residues (based on CS2) dissipated below limit of quantification (LOQ) on 10th and 15th day with half-life values of 1.91 and 2.33 days at recommended dose and double the recommended dose, respectively. The residues of mancozeb (based on CS2) in mature onions and soil collected at harvest were found to be below limit of quantification (LOQ).