EWS Plant Doctor

Causal Agent:

Fungi (Uromyces appendiculatus; Uromyces phaseoli)

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Characteristic Symptoms:

	Leaves, stems and fruits can be infected. Initial symptoms appear as tiny, whitish, slightly raised spots.

	Spots are surrounded by yellow halo and form reddish-brown pustules containing the rusty mass of spores/urediniospores.

	Severe infection causes drying of leaves and premature defoliation.

Conditions for Disease Development:

	Rust development is favored by cool to moderate temperatures (20-30°C) and moist conditions with prolonged periods of free water on the leaf surface for more than 10 hours.

	Urediniospores are dispersed by wind currents and can be carried to long distances.

Management and Control:

	Crop rotation with non-host crops.

	Remove weeds and volunteer beans/infested bean debris to reduce inoculum source.

	Use resistant varieties, if available.

	Apply chlorothalonil to protect the plants or at early stage of infection. Use azoxystrobin (Amistar®, MiradorⓇ, RobatoⓇ), pyraclostrobin (e.g.Cabrio 25 ECⓇ), difenoconazole (e.g. ScoreⓇ, MontanaⓇ, PursueⓇ, BashⓇ) or tebuconazole (e.g. Folicur®) to reduce rust severity after the appearance of symptoms.

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Rust