Management Of Powdery Mildew Research Articles

Management of powdery mildew on greenhouse cucumber (Cucumis sativus L.) plants using biological and chemical approaches

Powdery mildew, caused by Podosphaera xanthii (U. Braun & Shishkoff), is a widespread disease on greenhouse cucumber in many countries, including Canada. The efficacy of seven biological or chemical products to manage powdery mildew was evaluated. These included Rhapsody® (Bacillus subtilis Ehrenberg strain QST 713), Microflora PROTM (B. subtilis, Bacillus amyloliquefaciens Priest et al., Bacillus pumilus Meyer & Gottheil), Prestop® (Gliocladium catenulatum J.C. Gilman & E.V. Abbott strain J1446), Double Nickel LC (B. amyloliquefaciens strain D747), Active Flower™ (fertilizer containing N:P:K of 8:4:12 plus 3% boron), Luna® (fluopyram and pyrimethanil) and Pristine® (pyraclostrobin and boscalid). Products were applied as preventative or eradicative treatments at weekly intervals to the moderately susceptible cucumber cultivars ‘Picowell RZ’ or ‘Tasty Green’. Disease severity was rated after 3–4 applications as the number of colonies that developed on leaves, or as a percentage of leaf area infected calculated using image analysis. Rhapsody at a rate of 1.5% provided the most significant disease reduction compared with the other three biological products, although rates of 2% and 4% also resulted in high disease suppression in a second experiment. The fungicides Luna (0.5 mL L−1) and Pristine (0.66 g L−1) provided a level of control comparable to Rhapsody. Application of ActiveFlower at 0.5 and 0.3 mL 100 mL−1 significantly reduced powdery mildew after three applications, but some phytotoxicity was observed at the higher rate. The products tested in this study can be part of an integrated powdery mildew management programme for greenhouse cucumber.

Yield enhancement in mango crop with effective management of leaf hoppers and powdery mildew

A Front line demonstration was conducted on Management of leaf hoppers and powdery mildew in Mango crop at farmers fields of Nagarkurnool district, Telangana during the year 2016-17 to 2017-18. The main objective of front line demonstrations (FLDs) was to demonstrate study the efficacy of plant protection aspects for getting the higher yields. The demonstration comprised of two treatments viz., T1- Farmers practice (Sprayed Acephate 75% SP 1.5 gm/lt, Profenophos 50% EC 2ml/lt.of water) and T2-Demonstartion (Sprayed Thiomethoxam 25% WG 0.3 gm/l + Wettable Sulphur 90% WDG 3g/l at flower initiation stage and Imidacloprid 17.8% SL 0.3 ml + Hexaconazole 5% EC 2 ml/ lt at bud formation to marble fruit stage).The results showed that drastically reduced the average incidence leaf hoppers and powdery mildew. In demo only 10.50% and in farmers practice 22.50% of incidence of leaf hoppers and powdery mildew was observed. The cumulative effects of technological intervention over two years, revealed that mean average fruit yield was 108.92 q/ha under demo and 94.27 q/ha in compared to farmers practice. Net returns and B: C ratios were found to increase in demonstrated plots over farmers practice.

Evaluation of fungicides management of powdery mildew (Erysiphe Polygoni DC) disease of field pea (Pisum Sativum L.) in Eastern U.P.

The experiment was conducted to find out the efficacy of some new fungicides against powdery mildew (Erysiphe polygoni DC.) in the experimental field of experiment was laid out during rabi 2018-19 at supervision of Asha Bhagwan Bax Singh P.G. College Ayodhya, in the 7 farmer's field of Ayodhya and Ambedkarnager district of Uttar Pradesh. The experiment consisted of nine treatments viz. T1- Flusilazole 12.5% @ 1.0 ml/l., T2- Azoxystrobin 18.2 % w/w % @ 1.0 ml/l., T3- Tricyclazole 18 % @ 1.5 g/letter, T4- Propiconazole @ 1.0 ml/l., T5- Trifloxystrobin 25% @ 1.0 g/l, T6- Difenoconazole 11.4 % w/w SC @ 1.0 ml/l., T7- Mancozeb 50% @ 1.5 g/l., T8- Hexaconazole 4%WP @ 1.5 g/l.and T9- Untreated control (Spray of plain water), were applied the recommended dose of each product, were applied at the onset of disease. Minimum disease severity was recorded in propiconazole (8.58 % and 10.12 % at 10 and 20 days after spray respectively) followed by Azoxystrobin 18.2 % w/w (9.33 % and 11.17 % at 10 and 20 days after spray respectively) and significantly maximum disease intensity was observed in mancozeb (26.28 % and 29.13 % at 10 and 20 days after spray respectively) as compare to control (31.10 & 38.80%). The maximum pod yield of treated with propiconazole 11.13 t/ha increase over control 114.03% followed by Azoxystrobin 18.2 % w/w 10.18t/ha respectively.

Assessing the Curative and Protective Impacts of Select Fungicides for Control of Powdery Mildew of Wheat.

Powdery mildew, caused by the obligate fungal pathogen Blumeria graminis, has been increasing in incidence and severity on wheat in the Chesapeake Bay region of the mid-Atlantic United States. Although fungicides are used for in-season management of powdery mildew, no studies to date have assessed the ability of these products to control disease after pathogen arrival/infection (curative activity) and the duration of disease control provided after fungicide application (protective activity) under controlled conditions. Five commercially available fungicide products, including Caramba, Stratego YLD, Priaxor, Prosaro, and Trivapro, were applied at either 3 or 5 days after inoculation with B. graminis spores to assess curative activity. In a separate study, protective activity for these fungicides was assessed by applying fungicides and inoculating with B. graminis spores the same day and 21 and 42 days after fungicide application. All fungicides reduced powdery mildew severity on foliage compared with nontreated controls. Priaxor provided 11 to 18% less activity than other fungicides when applied curatively. All products provided protective control up to 42 days after inoculation, with Stratego YLD and Priaxor providing the greatest level of control at 68 and 56%, respectively. Our data indicate that different fungicides can have subtle differences in overall efficacy profiles that may translate to improved control or an extended control window in some situations, but all tested products provide very good to excellent control of powdery mildew on wheat.

Integrated management of Cercospora leaf spot and powdery mildew of sesame

Foliar diseases are the most destructive disease on Sesame. Among the foliar diseases Cercospora leaf spot, Alternaria blight, Powdery mildew and Bacterial blight are important diseases of sesame. Cercospora leaf spot caused by Cercospora sesamicola and powdery mildew caused by Oidium erysiphae are destructive diseases in India. Sesamum indicum has a large number of varieties and are susceptible to many pathogens. The occurrence and severity is location specific based on agro climatic situations. Hence, an attempt was made to identify the effective management practices for Cercospora leaf spot and powdery mildew in Sesame through integrated approach. Results revealed that, seed treatment with Trichoderma viride @ 10 g/kg and furrow application of enriched Trichoderma viride (Trichoderma viride 2.5 kg enriched in 100 kg FYM) @ 250 Kg/ha followed by spray of (Tebuconazole 50% + Trifloxistrobin 25% WG) @ 0.5 g/l recorded least per cent disease index for Cercospora leaf spot and powdery mildew 41.39 and 18.36 respectively, with the highest yield of 17.57 q/ha in treated as compared to untreated check 67.55 and 67.45 per cent disease index for Cercospora leaf spot and powdery mildew respectively, with grain yield of 7.59 q/ha indicating maximum yield loss. The maximum net returns and highest B: C ratio was also obtained in treatment (Tebuconazole 50% + Trifloxistrobin 25% WG) @ 0.5 g/l.

Effect of environmental conditions and phenology in the dispersal of secondary Erysiphe necator conidia in a vineyard

An integrated powdery mildew management strategy to identify the principal moments of secondary Erysiphe necator conidia dispersal in a vineyard based on aerobiological, phenological and meteorological data was developed. An adaptation of the physiological P-days model was conducted to obtain a descriptive equation for the prediction of the advantageous meteorological conditions for Erysiphe necator conidia dispersal in the vineyards of the Ribeiro Designation of Origin area. Moreover, a regression model was developed to predict the conidia concentration as a function of the weather and aerobiological variables with the highest influence on airborne E. necator spores. Additionally, phenological observations were conducted during the vegetative cycle of Vitis vinifera, with the aim to identify the most susceptible phenological stages to powdery mildew infection by relating them with the detected atmospheric spore concentrations. The study was carried out from 2008 to 2018 in an experimental vineyard. The E. necator spores were trapped using a Lanzoni VPPS-2000 sampler and the phenological observations were conducted following the BBCH standardized scale. The highest total fungal spore amount per season in the atmosphere of the vineyard was detected in 2013 with 4828 spores m-3, while the lowest amount was recorded in 2009 with 883 spores m-3. In general, the highest daily airborne spore concentrations were detected during the Flowering (stage 6) or in the previous and next stages, whereas the maximum total spore amount by stage was recorded during Development of Fruits (stage 7). The proposed threshold of P-days for potential secondary infections in the Ribeiro D.O. ranges from 120 to 160 P-days. The combination of aerobiological, phenological and meteorological data provides us a useful tool for the knowledge of the Erysiphe necator conidia dispersal behaviour bringing agricultural practices closer to a sustainable system.

Biological control of powdery mildew on Cornus florida using endophytic Bacillus thuringiensis

Powdery mildew (Erysiphe pulchra) is a devastating disease in nursery production of flowering dogwood (Cornus florida L.). Disease management relies heavily on season-long use of chemical fungicides and there is a demand for alternative strategies. An endophytic bacterium IMC8 was isolated from disease-free C. florida stem tissue, and was shown to be an effective biological control agent against E. pulchra in growth chamber, greenhouse and shadehouse environments. This isolate, identified as Bacillus thuringiensis, exhibited normal growth in NaCl concentrations up to 6%, pH 5 to 11, and temperatures up to 50°C. It was compatible with the conventional fungicide thiophanate methyl and clarified hydrophobic extract of neem seed oil at label recommended concentrations. The isolate IMC8 produced volatile compounds identified by GC/MS, which included antifungal and antibacterial compounds and suggested antibiosis as a mode of action. Scanning electron microscopy revealed lysis of powdery mildew spores and hyphae, which suggested parasitism as a second mode of action. These observations suggested that the isolate IMC8 has potential as a biological control agent in the management of powdery mildew on C. florida, and would tolerate a wide range of salinity, pH and high temperature conditions. It could be included as a component of integrated pest management in rotation or tank mix with lower levels of conventional fungicides, or used with clarified hydrophobic extract of neem seed oil.

Management of powdery mildew and behaviour of late blight under different irrigation configurations in organic tomato

Disease management options for organic tomato growers are limited. However, the dry winter in the Brazilian Mid-West is unfavourable to most foliar diseases, and is considered ideal for organic agriculture. We report on powdery mildew (PM) disease progress in organic tomato, under different irrigation configurations. The progress of late blight is also addressed. Staked, fresh-market tomatoes were grown in 2009 and 2010, under drip (DRP); furrow (FUR); microsprinkler (MIC); and overhead (OVH) systems. DRP, MIC and OVH were managed to maintain either high or moderate levels of soil moisture. FUR was managed to maintain moderate soil moisture only. In 2011, three treatments were added to study the extent of PM control with microsprinklers: MIC above plant canopy (MICAP); a DRP-MIC combination, above plant canopy, alternately used (DRP-MICA); and a DRP-MIC combination, where microsprinkler was applied as a PM control measure only (DRP-MICC). Irrigation systems that maximized leaf wetting provided the best PM control, reduced maximum disease severity (Ymax); severity at halfway point of the epidemic time course (Y50); area under disease progress curve (AUDPC); and disease progress rate (r). Overall, the intensity of late blight was much lower than PM, and no blight was detected in 2010. The DRP and FUR systems consistently hampered foliar diseases development in 2009/2011. PM is significantly reduced by irrigation management while late blight is a lesser disease in the Brazilian Mid-West winter season. Therefore, irrigation is a tool to control diseases in organic tomato, and likely, other cropping systems.

Powdery Mildew on Watermelon in Florida

This 3-page document discusses the symptoms and management of powdery mildew, a problematic fungal disease, on watermelon in Florida. Written by Pamela D. Roberts, Mathews Paret, and Nicholas Dufault and published by the UF/IFAS Plant Pathology Department, January 2019. http://edis.ifas.ufl.edu/pp342

Management of leaf spot (Cercospora canescens) and powdery mildew (Erysiphe polygoni) of cowpea through fungicides

Management of leaf spot (<i>Cercospora canescens</i>) and powdery mildew (<i>Erysiphe polygoni</i>) of cowpea through fungicides

Efficacy of newer fungicide molecule for the management of powdery mildew of Bhendi (Abelmoschus esculentus)

Efficacy of newer fungicide molecule for the management of powdery mildew of Bhendi (Abelmoschus esculentus)

Effect of Integrated Control Program of Powdery Mildew Disease on Growth and Productivity of Apple

Disease incidence % and disease severity % of the powdery mildew fungus(Podosphaera leucotricha) were assessed on Anna apple trees (Malus domestica, Borkh) budded on MM106 rootstock during 2016-2017 seasons in three different locations in Egypt. The disease occurrence was more prevailing in Qalyoubia governorate than the two orchard sites in Behaira (Kafr El Dawar and Noubaria). The efficacy of eleven foliar spray programs for management apple powdery mildew and on vegetative growth, fruiting parameters and fruit quality of Anna apple trees was evaluated in experimental farm at El-Qanater El-Khairia Horticultural Research Station in Qalyoubia, Agricultural Research Centre. All treatments reduced the disease severity % of powdery mildew with significant increase to all investigated vegetative growth measurements, fruiting parameters and fruit quality of Anna apple trees in relation to the control. The alternative fungicides in program 4 (Microvit, Punch and Topas) provided protection at an important level against powdery mildew infection and improved parameters and characters as compared with fungicide Microvit (P1), Punch (P2) or Topas (P3) each alone in the two seasons. In addition, alternation sprays among biofungicides in program 8 (Bio Zied , Bio Arc and AQ10) gave more efficiency, both growth and fruiting parameters and fruit characters as compared with those used in a single treatment in P5 (Bio Zied), P6 (Bio Arc) and P7 (AQ10). The effectiveness of Potassium Silicate in (P9) in inhibiting powdery mildew disease led to used it in alternation with Microvit and AQ10 in program10 as an integrated pest management (IPM) program. In general, the effectiveness of the alternative treatments with non-systemic fungicide Microvit, Potassium Silicate and AQ10 in (P10) was similar to that recorded of the systemic fungicides P2 (Punch) and P3 (Topas)) in both seasons. Results show that P10 can be used as alternative method for farmers to have eco-friendly management of powdery mildew with significant increase to the produced growth, productivity and fruit quality.

Adjusting Product Timing during the Powdery Mildew Critical Window to Improve Disease Management

Summary Goals: This project was designed to answer questions about the timing of different cultural (leaf removal) and chemical (fungicide rotation) disease management practices and how they influence the overall efficacy of a powdery mildew management program. Key Findings: The timing of specific chemical modes of action plays an important role in the overall efficacy of powdery mildew fungicide programs. In this study, programs in which the evaluated products were applied once during the critical window performed as well as programs in which the same products were applied twice (during the critical window and at bunch closure). This finding indicates that disease control depends on application of sprays during the critical window rather than later in the season. As expected, leaf removal significantly improved spray coverage in the fruit zone; however, this improved coverage did not last the entire season. Canopy refill, which occurred as summer laterals developed, reduced fruit-zone coverage later in the season. Leaf removal also did not result in any positive additive effects on overall disease control. Impact and Significance: These findings can be used to aid growers in the selection and rotation of products used for powdery mildew management programs to maximize the efficacy of disease control and minimize the risk of fungicide resistance. While early fruit zone leaf removal did not improve overall disease control in this high-pressure scenario, leaf removal resulted in improved spray coverage, which may enhance disease control when low-volume spray applications or contact-active chemistries are emphasized in a commercial program.

Occurrence period, severity and management of powdery mildew and rust in Jatropha curcas

ABSTRACT Jatropha curcas L. has been studied with the aim of attending the bioenergy demand in Brazil. In this study, the time of occurrence, the severity, and the control of powdery mildew and rust in a commercial crop were investigated. During the evaluation period, powdery mildew was first observed soon after the onset of the raining period in October. Rust was first observed in April. Metarhizium anisopliae. Azadirachta indica oil, J. curcas oil, and the fungicide triadimenol were efficient in controlling powdery mildew. None of these products nor potassium silicate did control rust.

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Management of powdery mildew of Euonymus japonicus in Kashmir Valley

Powdery mildew of Euonymus japonicus was managed by chemicals, bioagents and pruning based integrated disease management (IDM) approaches. Among fungicides flusilazole significantly reduced disease intensity by 8.30 and 1.36% as compared to 58.80 and 18.05% in check on leaves and twigs respectively, while, potassium bicarbonate was less effective than the fungicides. Among the biocontrol agents tested in vivo, Ampelomyces quisqualis was significantly superior in reducing the PDI by 34.71 and 9.72% on leaves and twigs as compared to 58.16 and 17.10% on check. Trichoderma viride was the least effective in reducing the PDI by only 40.53 and 12.17 on leaves and twigs, respectively. Pruning of twigs 6 cm below diseased area proved significantly superior to other pruning levels in checking the disease by 18.79 and 5.08% on leaves and twigs, respectively. In case of IDM approach, alternate sprays of flusilazole (0.02%) and A. quisqualis culture filtrate (50%) along with pruning of twigs (6 cm below diseased area) proved as the most effective integrated disease management strategy by exhibiting 2.33 and 0.16% disease intensity on leaves and twigs compared to 56.40 and 17.15% in the check.

Genome-wide identification of mildew resistance locus O (MLO) genes in tree model poplar (Populus trichocarpa): powdery mildew management in woody plants

Poplars are economically important fast growing trees. They are exposed to broad range of fungal diseases like powdery mildew (PM). MLOs (mildew resistance locus O), as plant susceptibility genes, act as negative regulators and whose loss-of-functions confer complete resistance to PM disease. Herein, work identified the MLO gene family members in poplar, a woody model species. A total of 26 identified MLOs (annotated as PtMLO1–26) were distributed on 14 poplar chromosomes either individually or in groups of two to four. PtMLO genes encoded a polypeptide of 341–593 residues with a characteristic MLO domain structure. One tandem and eight segmental duplications were revealed in PtMLO genes. PtMLO proteins anchored at plasma membrane and had putative 5–9 TMDs with extracellular/cytosolic N- and C-terminuses. They were rich in leucine (9.1–12.9%), which is reported to play roles in defense response signaling. The C-terminal calmodulin-binding domain (CaMBD), reported to modulate the signaling mechanism in the defense response, was completely preserved in all PtMLOs, except PtMLO6. This domain was partially absent in PtMLO6 which is inferred to be a different MLO type or a pseudogene with a lost/impaired function in PM response. Besides, second and third cytoplasmic loops that are critical for PM-susceptibility were identified in PtMLOs. Particularly, PtMLO17, 18, 19, and 24 genes, inferred from Arabidopsis-poplar comparative phylogeny, were identified as potential candidates that may be involved in poplar-PM resistance. Notably, inductions of 14 PtMLO genes were detected in probes of microarray data such as GSE56865, GSE16417, and GSE23726 under different fungal infections indicating their involvements in plant defense. Overall, this work provided a basis for woody plant genomics for the effective and better management of poplar-PM disease.

Management of Apple Scab and Powdery Mildew Using Bicarbonate Salts and Other Alternative Organic Products with Fungicide Effect in Apple Cultivars

The control of apple scab and powdery mildew is a challenge for organic fruit growing. Bicarbonate salts are already consecrate in reducing the attack of scab and powdery mildew in organic apple culture. In the current study the influence of some products accepted in organic apple production to control scab and powdery mildew (potasium bicarbonate, lime sulphur, wettable sulphur, potassium silicate, cooper ammonium-phosphate, potassium bicarbonate + potassium silicate, potassium bicarbonate + wettable sulphur) in comparison with untreated control, were used. The biological material was represented by three scab resistant cultivars (‘Luna’, ‘Topaz’ and ‘Sirius’) and three scab susceptible cultivars (‘Elstar’, ‘Pinova’ and ‘Golden Delicious’). The experiments were carried out during 2014-2016 at Steluța LTD, Cluj-Napoca, N.W. Romania, as a bifactorial experiment arranged in randomized blocks. The trees were planted in 2011 at a density of 3,175 trees/ha. Depending of the year, a number of 18-22 treatments were made annually after each rain. It can be concluded that the combination of potassium bicarbonate + wettable sulphur significantly reduced the attack degree of scab and powdery mildew on leaves and fruits and increased the yield of the scab-susceptible and scab resistant cultivars. Good results were obtained in the case of treatment with potassium bicarbonate with potassium silicate, potassium bicarbonate and cooper ammonium phosphate. The treatments with the products used in the experiments did not register symptoms of phytotoxicity on leaves or fruits, except lime sulphur and wettable sulphur and cooper ammonium phosphates.

Management of powdery mildew of pea with botanicals

Management of powdery mildew of pea with botanicals