Comparison of Fungicide Application Methods for Systemic Control of Sugar Beet Powdery Mildew

Rhizoctonia crown and root rot of sugar beet (Beta vulgaris L.), caused by Rhizoctonia solani, continues to be one of the important concerns for the beet industry in Minnesota and North Dakota. Use of resistant cultivars is an important strategy in the management of R. solani in combination with seed treatment and timely fungicide application during the growing season. The objective of this greenhouse study was to determine how sugar beet plants responded to increasing age in resistance to R. solani. Each of three seed companies provided three commercial cultivars with varying R. solani resistance levels: susceptible, moderately resistant, and resistant. Seed were planted at a weekly interval to create different plant age groups from seed to 10-week-old plants, with growing degree days (GDD) ranging from 0 to 1,519 thermal time (°Cd). Seed and plants were all simultaneously inoculated with R. solani AG2-2-infested barley grains. Twenty-eight days after inoculation, plants were pulled and washed, and roots were evaluated for disease severity. All cultivars were highly susceptible to R. solani when inoculated at seed to 3 weeks old (0 to 464°Cd). At 4 and 5 weeks of plant age (617 to 766°Cd), resistant cultivars started to show significant resistance to R. solani. Proportion of the affected roots with disease score ≥ 5 followed a sigmoid response, declining with increased GDD in moderately resistant and resistant cultivars, whereas it continued to decline linearly with increased GDD in susceptible cultivars. This study demonstrated that sugar beet cultivars, regardless of their assigned level of R. solani resistance, were highly susceptible to the pathogen before they reached the six- to eight-leaf stage at 4 to 5 weeks (617 to 766°Cd) after planting. Therefore, additional protection in the form of seed treatment or fungicide application may be required to protect sensitive sugar beet seed and seedlings in fields with a history of R. solani under favorable environmental conditions.

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Control of Rhizoctonia solani in Sugar Beet and Effect of Fungicide Application and Plant Cultivar on Inoculum Potential in the Soil

Plant Disease ◽

10.1094/pdis-09-16-1221-re ◽

2017 ◽

Vol 101 (6) ◽

pp. 941-947 ◽

Cited By ~ 9

Author(s):

Anika Bartholomäus ◽

Stefan Mittler ◽

Bernward Märländer ◽

Mark Varrelmann

Keyword(s):

Sugar Beet ◽

Rhizoctonia Solani ◽

Natural Infection ◽

Resistance Management ◽

The United States ◽

Similar Efficacy ◽

Field Trials ◽

Crown Rot ◽

Inoculum Potential ◽

Fungicide Application

Rhizoctonia solani (AG 2-2 IIIB) is the causal agent of Rhizoctonia root and crown rot, a disease that causes severe economic problems in sugar beet growing areas worldwide. In the United States, azoxystrobin is the most important active ingredient for fungicidal control of R. solani in sugar beet, showing efficacy superior to other substances. First reports on resistance development in R. solani, however, underline the importance of a careful fungicide resistance management. For this reason, the efficacy of a new fungicide mixture of azoxystrobin and difenoconazole was compared with a fungicide containing only azoxystrobin. Field trials were carried out under natural infection conditions as well as with inoculation in the years 2012, 2013, and 2014. Evaluation of the disease severity and the obtained white sugar yield of different sugar beet cultivars demonstrated that both fungicide treatments possess a similar efficacy, reducing the diseased beet surface by up to 78% and preventing yield losses. Additionally, a real-time PCR assay, based on DNA extracts from representative soil samples (250 g), was used to directly determine the effect of chemical treatment and plant cultivar on the soil-borne inoculum. Fungicide application significantly reduced the concentration of soil-borne inoculum by up to 97%. Furthermore, the results demonstrated that the cultivation of a susceptible cultivar significantly increases the concentration of R. solani in the soil by a factor of 200. In conclusion, the study implies that only a combination of resistant cultivar and fungicide application can prevent an accumulation of R. solani inoculum under conducive conditions in infested fields.

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Impact of Powdery Mildew and Leaf Rust on Milling and Baking Quality of Soft Red Winter Wheat

Plant Disease ◽

10.1094/pdis.2001.85.4.423 ◽

2001 ◽

Vol 85 (4) ◽

pp. 423-429 ◽

Cited By ~ 45

Author(s):

Kathryne L. Everts ◽

Steven Leath ◽

Patrick L. Finney

Keyword(s):

Powdery Mildew ◽

Winter Wheat ◽

Leaf Rust ◽

Fungicide Application ◽

Baking Quality ◽

Soft Red Winter Wheat ◽

Flour Yield ◽

Foliar Fungicide ◽

Red Winter Wheat ◽

The Relationship

Changes in milling and baking quality (especially flour yield) of soft red winter wheat can have a large economic impact on flour mills. To determine the relationship between early-season powdery mildew and late-season leaf rust on flour yield, flour protein, alkaline water retention capacity, and kernel texture (softness equivalent), a study was conducted over 2 years at Kinston and Plymouth, NC. Different levels of powdery mildew and leaf rust developed on three winter wheat cultivars that varied in levels of disease resistance, the presence of seed treatment, and the presence and timing of foliar fungicide application. In Kinston and Plymouth in 1989-90, where leaf rust occurred early, the softness equivalent score was lower in wheat grown from seed treated with triadimenol. The following year, when the leaf rust epidemic increased later, foliar fungicide application reduced disease and resulted in lower softness equivalent scores in both Plymouth and Kinston for cv. Saluda and in Kinston for cv. Coker 983. A regression model was developed to describe the relationship between the log of the area under the disease progress curves and adjusted flour yield (AFY). The AFY of Saluda was reduced in the presence of powdery mildew such that %AFY = 103.96 - 0.92 (log AUMPC).

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Fungal disease resistance of perspective sugar beet varieties and their yield potential

Žemės ūkio mokslai ◽

10.6001/zemesukiomokslai.v25i1.3665 ◽

2018 ◽

Vol 25 (1) ◽

Author(s):

Agnė Sadauskienė ◽

Zita Brazienė ◽

Zenonas Dabkevičius

Keyword(s):

Powdery Mildew ◽

Sugar Beet ◽

Causative Agent ◽

Leaf Spot ◽

Sugar Content ◽

Yield Potential ◽

Leaf Spot Disease ◽

Root Yield ◽

Spot Disease ◽

Fungal Disease Resistance

The research was conducted on 11 sugar beet varieties, grown at the Rumokai Experimental Station of the Lithuanian Research Center for Agriculture and Forestry, in 2016 and 2017. The experiments were carried out on two backgrounds: the crops were not sprayed and sprayed with fungicide epoxiconazole 125 g l–1. During the study years, rust (causative agent Uromyces beticola), powdery mildew (causative agent Erysiphe betae Vaňha Weltzien) and leaf spot disease (causative agent Cercospora beticola Sacc.) were the most prevalent in sugar beet. Rust, the intensity of which was 9.66–61.79%, caused most damage to sugar beet. The intensity of powdery mildew was 12.71–55.98% and that of leaf spot disease was 7.47–54.23%. Of the investigated varieties of sugar beet, the most sensitive to leaf spot disease were ‘Merens’, ‘Balear’, ‘Davinci’, ‘Kashmir’ and ‘Pottok’, the most resistant were ‘Berton’, ‘Selma KWS’ and ‘Wellington’. ‘Merens’ and ‘Texel’ were the most sensitive to rust. This disease was least damaging to the ‘Minta’, ‘Berton’ and ‘Strauss’ varieties. Powdery mildew was most harmful to leaves of the ‘Merens’, ‘Balear’ and ‘Minta’ varieties of sugar beet. The most resistant to powdery mildew was ‘Texel’. According to the average two-year data, the most productive was the ‘Pottok’ variety, whose root yield was 90.46– 93.85 t ha–1. The ‘Straus’ variety had the highest sugar content. Epoxiconazole increased the sugar beet yield from 0.44 to 6.53 t ha–1 in 2016 and from 0.07 to 11.63 t ha–1 in 2017.

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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.)

Irriga ◽

10.15809/irriga.2006v11n3p328-338 ◽

2006 ◽

Vol 11 (3) ◽

pp. 328-338

Author(s):

Ieoschua Katz ◽

Antonio Ribeiro da Cunha ◽

Antonio De Pádua Sousa ◽

Egberto Egon de Herdani

Keyword(s):

Disease Control ◽

Botrytis Cinerea ◽

Drip Irrigation ◽

Eustoma Grandiflorum ◽

Stage Number ◽

Thiophanate Methyl ◽

Fungicide Application ◽

Potted Plants ◽

Application Methods ◽

Lower Production

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

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Impact of Different Application Methods and Concentrations of Ascorbic Acid on Sugar Beet under Salinity Stress Conditions

Alexandria Journal of Agricultural Sciences ◽

10.21608/alexja.2020.90853 ◽

2020 ◽

Vol 65 (1) ◽

pp. 31-44 ◽

Cited By ~ 1

Author(s):

M. Abdel Fatah Eman ◽

Sadek K.A.

Keyword(s):

Ascorbic Acid ◽

Sugar Beet ◽

Salinity Stress ◽

Stress Conditions ◽

Application Methods

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Effect of some Plant Extracts on Sugar Beet Powdery Mildew

Egyptian Journal of Phytopathology ◽

10.21608/ejp.2016.91924 ◽

2016 ◽

Vol 44 (1) ◽

pp. 49-56

Author(s):

Medhat Abd-Rabboh ◽

Mohamed El-Shennawy

Keyword(s):

Powdery Mildew ◽

Sugar Beet ◽

Plant Extracts

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Occurrence of the Perfect Stage of Powdery Mildew of Sugar Beets in Southern Montana in 2003

Plant Disease ◽

10.1094/pd-89-1362b ◽

2005 ◽

Vol 89 (12) ◽

pp. 1362-1362

Author(s):

B. Jacobsen ◽

M. R. Johnston ◽

H. C. Weltzien

Keyword(s):

Powdery Mildew ◽

Sugar Beet ◽

Genetic Recombination ◽

Its Region ◽

The United States ◽

Long Distance ◽

Separate Species ◽

Sugar Beets ◽

Perfect Stage ◽

Erysiphe Polygoni

Wide spread powdery mildew infections on sugar beets were observed at the Southern Agricultural Experiment Station in Huntley, MT during September, 2003. Throughout the area, lower leaves were frequently heavily covered by the vegetative stage of the fungus with plants at the edge of the field having clearly visible abundant mature (black) and immature (brown) globose ascocarps on the leaf surfaces and stems. The fruiting structures had mostly branched appendages and were imbedded in the superficial mycelium. Their diameter ranged from 70 to 100 μm. Each ascocarp contained five to eight asci with one to four ascospores (mostly three) per ascus. Elliptical ascospores were hyaline and measured 20 to 25 μm long and 12 to 20 μm wide. On the basis of the descriptions given for isolates from Idaho and Colorado (1) and the usage of Erysiphe polygoni DC for powdery mildew on sugar beet in the United States, this isolate may be classified as E. polygoni DC. However, measurements taken show that ascocarps, asci, and ascospores also fall within the range of E. betae (Vanha) Weltz. as described by Weltzien (2). We strongly suggest that these species be compared by using rDNA analysis of the ITS region to determine whether they are separate species. If survival of the ascocarps and the viability and pathogenicity of the ascospores can be confirmed, epidemics of sugar beet powdery mildew could be understood as local and regional events that are not dependant on long distance dispersal of conidiospores. The occurrence of the perfect stage also could lead to the more frequent appearance of new races through genetic recombination. References: (1) J. J Gallian and L. E. Hanson. Plant Dis. 87:200, 2003. (2) H. C. Weltzien. Phytopathol. Z. 47:123, 1963.

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