Syngenta’s Amistar and Ridomil Gold MZ fungicides control white blister disease
Syngenta , a well-known crop protection company, offers management strategies to help with the control of white blister.
Syngenta also offers effective fungicides like Amistar and Ridomil Gold MZ to control white blister.
Symptoms of white blister include the following:
- Yellow to brown spots form on the upper leaf surface and white; round to oval blisters develop on the matching under leaf surface
- The blisters consist of masses of white dust-like spores
- The fungus can cause swellings on roots and stems, and distortions of flowers and leaves
Conditions for infection
- Free water (dew, fog, irrigation or rain) on leaves and stems
- Spores germinate at temperatures of 1°C to 20°C, with the optimum range being10°C to 14°C
- The good conditions for spores to infect plants are 3 hours of leaf wetness at 20°C
- Blisters take 6 to 10 days to form after infection
Source of the disease
- Diseased plants or crops
- Volunteer crucifers
- Wild crucifers and crucifer weeds
- Debris
- Seed
Spread
- Wind, rain or insects disperse aerial spores
- Rain splash of spores from soil onto the plant
Management strategies to help with the control of white blister may include any or all of the following:
Controlled watering
- A short, heavy watering is preferable to a long, light watering
- If possible avoid night irrigation
Ventilation
- Maintain good air-movement in the environment to dry leaves off quickly and reduce infection
Nutrition
- Maintain a balanced nutrition programme, in order to reduce any stresses on the plant
Hygiene
- Remove sources of spores, such as volunteer radish, crucifer weeds and if possible crop debris.
Fungicides
Both Amistar and Ridomil Gold MZ have current minor use permits for control of White blister in certain brassica crops.
Amistar
Amistar, available from Syngenta, is an effective fungicide that can be used to control White blister.
Crop
- Broccoli
- Brussels sprouts
- Cauliflower
Pest
- White blister (Albugo candida)
Rate
Critical comments:
If Amistar ahs not been applied in a protective spray pattern, spray at the first signs of infection. Apply 2 (only) consecutive sprays 7-10 days apart.
Thereafter, use another registered chemical group. Apply in sufficient water to ensure through coverage of all plant parts.
Permit period:
- 31 March 2006 to 31 August 2007
The maximum number of Amistar applications permitted is 2 per crop
Withholding period (Harvest):
- Do not harvest for 7 days after application
Ridomil Gold MZ
Crop
- Broccoli, cauliflower and Brussels sprout, Brassica leafy vegetables
Pest
- White blister (Albugo candida)
Rate
Critical comments
- Apply by boom spray. Make two applications 7-10 days apart during head formation
Permit period:
- 5 September 2005 to 31 March 2008
Withholding period:
- Do not harvest for 7 days after application to broccoli cauliflower and Brussels sprout
- Do not harvest for 14 days after application to brassica leafy vegetables
5-Aug-2008