Chemigation with benomyl and fluazinam and their fungicidal effects in soil for white mold control on dry beans

The effectiveness of fungicides in controlling white mold (Sclerotinia sclerotiorum) of dry beans (Phaseolus vulgaris) was evaluated when they were applied through irrigation water directly onto the plants or only to the soil. Two field trials were installed in April 1998 and April 1999 in Viçosa, MG. Trials were conducted as a (2 x 3) + 1 factorial: two fungicides x three application modes + one untreated control. The fungicides were benomyl (1.0 kg a.i. ha-1) and fluazinam (0.5 l a.i. ha-1). The three application modes were: (a) by backpack sprayer (667 l ha-1), (b) by garden watering-cans simulating sprinkler irrigation with 35,000 l ha-1 of water, and (c) by garden watering-cans applying water between the rows and near the soil surface in 35,000 l ha-1 of water. In 1998, fungicides were applied at 43 and 54 days after emergence (DAE); in 1999, at 47 and 61 DAE. Both fungicides were similarly effective on white mold control when applied by either chemigation or backpack sprayer, resulting in yields 21% higher than untreated control. Only fluazinam provided disease control when applications were made only in soil. Chemigation provided white mold control equivalent to that of backpack sprayer in terms of incidence, severity and number of diseased pods. Consequently, yield differences between these application methods were not significant.

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Effect of genetic blends of dry beans (Phaseolus vulgaris) of different Plant architecture on apothecia production of Sclerotinia sclerotiorum and white mold infection

Euphytica ◽

10.1007/bf00039139 ◽

1978 ◽

Vol 27 (1) ◽

pp. 225-231 ◽

Cited By ~ 4

Author(s):

Dermot P. Coyne ◽

J. R. Steadman ◽

H. F. Schwartz

Keyword(s):

Phaseolus Vulgaris ◽

Sclerotinia Sclerotiorum ◽

Plant Architecture ◽

White Mold ◽

Dry Beans

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Efficacy of three greenhouse screening methods for the identification of physiological resistance to white mold in dry bean

Canadian Journal of Plant Science ◽

10.4141/cjps08230 ◽

2009 ◽

Vol 89 (4) ◽

pp. 755-762 ◽

Cited By ~ 11

Author(s):

H Terán ◽

S P Singh

Keyword(s):

Phaseolus Vulgaris ◽

Common Bean ◽

Sclerotinia Sclerotiorum ◽

Screening Method ◽

White Mold ◽

Screening Methods ◽

Post Inoculation ◽

Dry Bean ◽

Physiological Resistance ◽

Nueva Granada

White mold (WM) caused by Sclerotinia sclerotiorum (Lib.) de Bary is the most devastating disease of common bean (dry and snap or garden bean) (Phaseolus vulgaris L.) in North America. The use of a reliable screening method (SM) in common bean is crucial to improve physiological resistance to WM. The objective of this study was to compare the efficacy of three SM to identify physiological resistance in dry bean genotypes with different evolutionary origins and levels of resistance. Screening methods tested were: (i) the modified straw test or cut–stem (CSM); (ii) infected bean flower (IFL); and (iii) infected oat seed (IOS). A 195, ICA Bunsi, Othello, and VCW 54 dry bean were tested with the three SM. The experimental design was a split plot in randomized complete blocks with three replications in 2007 and 2008. Two independent inoculations 1 wk apart for each SM were made. The WM reaction was scored at 16, 23, and 33 d post-inoculation (DPI) using a 1 to 9 scale. There were highly significant differences between SM and its interaction with years. The CSM and IFL were the most consistent and highly correlated (r > 0.70, P < 0.01). Interspecific breeding line VCW 54 consistently had the highest WM resistance across years, SM, and evaluation dates, followed by A 195. White mold scores increased with delayed evaluations. Thus, CSM or IFL with disease assessed 33 DPI should be used for identifying common bean genotypes with high levels of physiological resistance to WM.Key words: Common bean, growth habit, race Mesoamerica, race Nueva Granada, Phaseolus vulgaris, Sclerotinia sclerotiorum

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First Report of White Mold Caused by Sclerotinia sclerotiorum on Oreganum vulgare and Taraxacum officinale in Italy

Plant Disease ◽

10.1094/pdis-91-10-1360c ◽

2007 ◽

Vol 91 (10) ◽

pp. 1360-1360

Author(s):

A. Garibaldi ◽

A. Minuto ◽

M. L. Gullino

Keyword(s):

Sclerotinia Sclerotiorum ◽

Soil Surface ◽

Taraxacum Officinale ◽

White Mold ◽

Economic Losses ◽

Medicinal Uses ◽

First Report ◽

Potted Plants ◽

Mycelial Plug ◽

Commercial Farms

Oreganum vulgare (wild marjoram) and Taraxacum officinale (dandelion) plants with culinary and medicinal uses are grown in the field and as potted plants in Liguria in northern Italy. In the spring of 2006, extensive chlorosis was observed on both crops on commercial farms. Economic losses were low. Symptoms included foliar necrosis and a watery decay of the stem at the soil level. Necrotic tissues became covered with a whitish mycelium that produced dark sclerotia. Eventually, affected plants wilted and died. Samples of diseased stem tissue were surface sterilized for 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 mg/l of streptomycin sulfate. Sclerotinia sclerotiorum (Lib.) de Bary (1) was consistently recovered from diseased stem pieces. Sclerotia from infected O. vulgare plants measured 1.8 to 3.4 × 1.8 to 6.1 (average 2.5 to 3.6) mm. Sclerotia from these isolates measured 1.3 to 4.7 × 1.6 to 6.1 (average 2.7 to 3.4) mm on PDA. Sclerotia from infected T. officinale plants measured 1.8 to 3.4 × 1.8 to 6.1 (average 2.5 to 3.6) mm. Sclerotia from these isolates measured 1.7 to 5.2 × 2.0 to 5.7 (average 3.3 to 3.8) mm on PDA. Pathogenicity of three isolates obtained from O. vulgare and three isolates from T. officinale was confirmed on each host. Inoculum consisted of 1 cm2 of mycelial plugs excised from a 10-day-old PDA culture of each isolate. Plants were inoculated by placing a mycelial plug on the soil surface around the base of each plant. Ten plants were inoculated per isolate and an equal number of noninoculated plants served as controls. Plants were incubated at 10 to 27°C (average 18°C) and watered as needed. Pathogenicity tests were repeated once. All inoculated plants developed chlorosis within 12 to 18 days, followed by the appearance of white mycelium and sclerotia, and eventually wilt. Control plants remained symptomless. S. sclerotiorum was reisolated from inoculated plants of both hosts. To our knowledge, this is the first report of white mold on O. vulgare in Italy as well as worldwide and the first report of white mold on T. officinale in Italy. S. sclerotiorum is a well known pathogen of T. officinale (2) and its use as a mycoherbicide has been proposed (3). References: (1) N. F. Buchwald. Page 75. Den. Kgl. Veterin.er-og Landbohojskoles Aarsskrift, 1949. (2) D. M. McLean. Plant Dis. Rep. 35:162, 1951 (3) G. E. Riddle et al. Weed Sci. 39:109, 1991.

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First Report of White Mold Caused by Sclerotinia sclerotiorum on Common Sage (Salvia officinalis) in Italy

Plant Disease ◽

10.1094/pdis.2004.88.9.1044b ◽

2004 ◽

Vol 88 (9) ◽

pp. 1044-1044

Author(s):

A. Garibaldi ◽

A. Minuto ◽

M. L. Gullino

Keyword(s):

Sclerotinia Sclerotiorum ◽

Plant Density ◽

Soil Surface ◽

Salvia Officinalis ◽

White Mold ◽

Rooted Cuttings ◽

First Report ◽

Streptomycin Sulfate ◽

High Plant Density ◽

White Mycelium

Salvia officinalis L. is cultivated as an aromatic ornamental plant in Italy. In the spring of 2003, rooted cuttings grown in containers in commercial farms near Albenga (northern Italy) had soft and watery stem tissue covered with whitish mycelium at the soil level. Leaves and stems showed necrotic areas of irregular shape and size. As necrosis progressed, infected plants wilted and died. Wilt occurred within a few days on young plants. Because of high plant density, the pathogen spread rapidly within and across containers to infect many rooted cuttings. Sclerotinia sclerotiorum (Lib.) de Bary (2) was consistently recovered from infected stem pieces of Salvia officinalis that were disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 ppm of streptomycin sulfate. Sclerotia produced on PDA were ellipsoid and measured 1.4 to 4.2 × 1.1 to 2.1 (average 2.1 × 1.5) mm. Pathogenicity of three isolates obtained from infected plants was confirmed by inoculating 30-day-old plants grown in pots (14-cm diameter). Inoculum of each isolate was 14-day-old cultures of mycelium and sclerotia grown on sterile wheat kernels (300 g) and deionized water (320 ml) in a 1-liter flask at 20 to 25°C. Inoculum (10 g) of each isolate was placed on the soil surface around the base of 10 plants. Ten noninoculated plants served as controls. The inoculation trial was repeated once. All plants were kept in a screenhouse at temperatures ranging between 8 and 31°C and watered as needed. Inoculated plants developed symptoms of leaf yellowing, followed by the appearance of white mycelium within 7 days, and eventually wilted within 12 to 15 days. Control plants remained symptomless. White mycelium and sclerotia developed on infected tissues, and S. sclerotiorum was reisolated from inoculated plants on PDA amended with 100 ppm of streptomycin sulfate. To our knowledge, this is the first report of white mold of Salvia officinalis caused by S. sclerotiorum in Italy. The disease has been observed in Canada (1) as well as Tasmania and New Zealand. References: (1) G. J. Bolland and R. Hall. Can. J. Plant Pathol. 16:93, 1994. (2) N. F. Buchwald. Den. Kgl. Veterin.er-og Landbohojskoles Aarsskrift, 1949.

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Field Trials with Canadian Wonder Beans in Malawi

Experimental Agriculture ◽

10.1017/s001447970000555x ◽

1973 ◽

Vol 9 (2) ◽

pp. 97-105 ◽

Cited By ~ 5

Author(s):

A. T. Spurling

Keyword(s):

Phaseolus Vulgaris ◽

Deleterious Effect ◽

Field Trials ◽

Dry Beans ◽

Plant Populations

SUMMARYIn fifteen field trials with Phaseolus vulgaris cv. Canadian Wonder time of planting was the most important factor affecting yield of dry beans in the Shire Highlands of Southern Malawi. Under-cropping maize with beans had no deleterious effect on the yield of maize and gave a worthwhile yield of beans. Little response was found to different plant populations when conditions for growth were good, but when conditions were poor yields were greatest from the highest population of 47,000 plants per hectare. A response in yield was obtained from 11 kg. N ha.−1 but there was no effect of source of nitrogen or response to phosphate, potash or inoculation.

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Numbers and distribution of apothecia of Sclerotinia sclerotiorum in relation to white mold of white bean (Phaseolus vulgaris)

Canadian Journal of Botany ◽

10.1139/b88-042 ◽

1988 ◽

Vol 66 (2) ◽

pp. 247-252 ◽

Cited By ~ 18

Author(s):

G. J. Boland ◽

R. Hall

Keyword(s):

Phaseolus Vulgaris ◽

Sclerotinia Sclerotiorum ◽

Negative Binomial Distribution ◽

Negative Binomial ◽

Disease Incidence ◽

White Mold ◽

Spatial Distributions ◽

Phaseolus Vulgaris L ◽

Field Plot ◽

White Bean

Relationships between the distribution and numbers of apothecia of Sclerotinia sclerotiorum (Lib.) de Bary and the distribution and incidence of white mold of white bean (Phaseolus vulgaris L.) were investigated in a field plot at Arkell, Ont., in 1981 and 1982. The spatial distributions of both apothecia and disease were aggregated and were most consistently described by the negative binomial distribution, although the Poisson, Poisson binomial and logarithmic with zeros distributions were also significant for some sampling dates. Numbers of apothecia were correlated with disease incidence within areas 1.4 (r = 0.07–0.67), 36 (r = 0.11–0.72), and 108 m2 (r = 0.21–0.95). The quantitative relationships between apothecia within a field of beans and the incidence of white mold may be useful in predicting the disease.

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Response of bush and upright plant type selections to white mold and seed yield of common beans grown in various row widths in southern Ontario

Canadian Journal of Plant Science ◽

10.4141/cjps93-041 ◽

1993 ◽

Vol 73 (1) ◽

pp. 265-272 ◽

Cited By ~ 24

Author(s):

S. J. Park

Keyword(s):

Phaseolus Vulgaris ◽

Sclerotinia Sclerotiorum ◽

Seed Yield ◽

Genetic Resistance ◽

White Mold ◽

Plant Type ◽

Lodging Resistance ◽

Row Width ◽

Dry Edible Bean ◽

Canopy Type

White mold, caused by Sclerotinia sclerotiorum (Lib.) de Bary, is an important disease in common bean (Phaseolus vulgaris L.) production areas. It reduces seed yield and lowers the quality of beans. Development of the disease is thought to be affected by plant canopy type (architecture), and by genetic resistance. This study determined the effect of plant type and row width on white mold and seed yield. Three short bush/vine and four semi-determinate upright genotypes were tested in narrow (30 cm) and wide (60 and 80 cm) rows for 2 yr in a field prone to white mold development. Incidence and disease index increased as row width became narrower. The upright type was infected less than the short bush type. Ex Rico 23, which is a short vine, open canopy type, was moderately resistant to the mold. A tall upright selection, A55, showed the lowest mold infection; it was significantly less than that of Ex Rico 23. Seed yield of all genotypes increased as row width decreased even though there was an increase in white mold incidence. Stiff-strawed upright types had less lodging. To reduce white mold, cultivars should have lodging resistance, narrow canopied upright plant type and genetic resistance. Development of the upright plant types allows for narrow-row production and direct combining. Key words: Dry edible bean, Phaseolus vulgaris, white mold, Sclerotinia sclerotiorum, plant type, row width, seed yield

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First Report of White Mold Caused by Sclerotinia sclerotiorum on Thymus × citriodorus in Italy

Plant Disease ◽

10.1094/pdis.2004.88.9.1044a ◽

2004 ◽

Vol 88 (9) ◽

pp. 1044-1044

Author(s):

A. Garibaldi ◽

A. Minuto ◽

M. L. Gullino

Keyword(s):

Sclerotinia Sclerotiorum ◽

Soil Surface ◽

White Mold ◽

First Report ◽

Potted Plants ◽

Inoculation Trial ◽

Initial Symptoms ◽

Commercial Farms ◽

Stem Necrosis ◽

White Mycelium

Thymus × citriodorus is well known for the citrus aroma released by its leaves and is grown as a potted plant in northern Italy. This species is widely used in gardens and landscapes and for culinary purposes. In the Liguria Region alone, 1.5 million plants are grown. In the winter of 2002, extensive chlorosis was observed on potted plants of Thymus × citriodorus cv. Silver Queen grown outdoors on commercial farms near Albenga. Initial symptoms included stem necrosis at the soil level and darkening of leaves. As stem necrosis progressed, infected plants wilted and died. Wilt, characterized by the presence of soft and watery tissues, occurred within a few days on young plants. Necrotic tissues became covered with whitish mycelium that produced dark sclerotia. Sclerotinia sclerotiorum (Lib.) de Bary (1) was consistently recovered from infected stem pieces of Thymus × citriodorus. The diseased stem tissue was disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 ppm of streptomycin sulfate. Sclerotia produced on PDA were ellipsoid and measured 5.2 to 4.4 × 2.1 to 1.5 mm (average 3.5 × 3.0 mm). Pathogenicity of three isolates obtained from infected plants was confirmed by inoculating 30-day-old plants grown in 14-cm-diameter pots in a screenhouse. Inoculum that consisted of wheat kernels infested with mycelium and sclerotia of each isolate was placed on the soil surface around the base of each of 10 plants. Noninoculated plants served as controls. The inoculation trial was repeated once. All plants were kept at temperatures ranging between 5 and 26°C and watered as needed. Inoculated plants developed symptoms of leaf yellowing within 13 days, soon followed by the appearance of white mycelium, and eventually wilted. Control plants remained symptomless. White mycelium and sclerotia developed on infected tissues and S. sclerotiorum was reisolated from inoculated plants. To our knowledge, this is the first report of white mold of Thymus × citriodorus caused by S. sclerotiorum. The economic importance of this disease for the crop can be considered low. Reference: (1) N. F. Buchwald. Den. Kgl. Veterin.er-og Landbohojskoles Aarsskrift, 1949.

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Screening for Partial Physiological Resistance to White Mold in Dry Bean Using Excised Stems

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.117.2.321 ◽

1992 ◽

Vol 117 (2) ◽

pp. 321-327 ◽

Cited By ~ 16

Author(s):

P.N. Miklas ◽

K.F. Grafton ◽

B.D. Nelson

Keyword(s):

Phaseolus Vulgaris ◽

Sclerotinia Sclerotiorum ◽

Field Resistance ◽

White Mold ◽

Lesion Length ◽

Laboratory Procedure ◽

Dry Bean ◽

Snap Bean ◽

Breeding Lines ◽

Physiological Resistance

A laboratory procedure was tested to determine whether excised stems would allow a reliable indication of partial physiological resistance (PPR) to white mold [Sclerotinia sclerotiorum (Lib.) deBary] in dry bean (Phaseolus vulgaris L.). Excised stems from 11- and 28-day-old plants were inoculated with growing mycelium of S. sclerotiorum, incubated for 4 to 7 days (11- and 28-day assays, respectively), then assayed for lesion length (LL). A total of 15 bean genotypes were screened for PPR, as indicated by LL. Significant (P < 0.05) differences among LL means of small- and medium-seeded bean genotypes were detected in the 28-day assay, whereas only LL means among medium-seeded genotypes. differed significantly (P < 0.05) in the n-day assay. `Bunsi', `C-20', `Sierra', `Topaz', and snap bean breeding lines NY 5262, NY 5394, and NY 5403 had the highest PPR and `Upland', D76125, and `UI-114' the lowest. The results from both assays were repeatable. A moderately high correlation (r = 0.68, P < 0.02) was observed between PPR and field resistance. The 28-day assay has potential for evaluating dry bean germplasm for PPR to white mold disease caused by S. sclerotiorum. A 28-day assay also was used to measure virulence of 18 isolates of S. sclerotiorum. The 18 isolates did not differ (P < 0.05) for virulence when measured by LL. The lack of any genotype × isolate interaction for LL indicated lack of host-pathogen specificity.

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