Disease control programmes using Rudis and Nativo 75WG fungicides for Brussels sprouts, cabbage, broccoli/calabrese and cauliflower crops.

Example programmes

Brussels sprouts
No disease at T1

A: Alternative product with different Mode(s) of Action. Follow FRAC guidelines.

Light Leaf Spot

Warm, wet autumns are driving the spread of Light Leaf Spot (LLS: Pyrenopeziza brassicae) to the UK’s prime brassica-growing areas. LLS can severely depress crop quality, yield and revenue – particularly in long-season crops such as Brussels sprouts and storage cabbages.

Control is best achieved with preventative sprays as part of an integrated programme approach: curative applications are much less effective.

If white blister is present, add a specific oomycete curative fungicide, such as Infinito, to control the disease.

Autumn/winter cabbage
Disease at T1

Application:

The first application is recommended before disease establishes in the crop. Follow with further applications of Rudis or Nativo 75WG at a typical spray interval of 21 days. A minimum of 21 days between applications is required when using the same product in a block spray. Apply Nativo 75WG at the end of a programme for lasting crop protection and better storage.

As part of a disease resistance management strategy, Nativo 75WG and Rudis should be used in a fungicide spray programme with other products based on different classes of chemistry.

Brassica leaf spot disease (Alternaria species, Mycosphaerella brassicicola) control

For control of these diseases or for curative activity against other target diseases, mixing Rudis or Nativo 75WG with an approved sticker/wetter adjuvant may enhance their activity.

White blister (Albugo candida) control

Nativo 75WG provides useful protection against white blister; for established infections use a specific oomycete curative fungicide such as Infinito (EAMU 20152557). Mix Rudis with an oomycete curative fungicide for control.

New transplants

Allow to establish before applying Nativo 75WG; there is potential for some growth regulation seen principally as a transient reduction in vigour of young plants.

Resistance management

Nativo 75WG contains trifloxystrobin, a member of the Qol group. In accordance with FRAC guidelines for pre-mix Qol fungicides, the number of applications of Qol-containing products should be no more than 50% of the spray programme.

Rudis contains prothioconazole, a member of the DMI group.

Use Rudis and Nativo 75WG as part of an Integrated Crop Management (ICM) strategy incorporating other methods of control, including where appropriate other fungicides with a different mode of action.

Using Rudis and Nativo 75WG fungicide programmes to ensure quality and yields.

Example programme

Disease at T1

If the crop is disease-free, apply Nativo 75WG first.

Application

Rudis must only be used on carrots that are to be mechanically harvested.

The first application is recommended before disease establishes in the crop. Follow with further applications of Rudis or Nativo 75WG at a typical spray interval of 14 days according to disease pressure. You may apply Rudis or Nativo 75WG three times each per crop. A minimum of 21 days between applications is required when using the same product in a block spray.

Apply Nativo 75WG at the end of a programme for lasting crop protection and better storage.

Sclerotinia control

Use a disease forecasting system to time the first application before disease establishes itself in the crop – typically prior to canopy closure in June-July. This is particularly important for Sclerotinia sclerotiorum control to ensure all leaves are adequately protected before the microclimate under the crop canopy becomes optimal for spore release from soil-germinating fungal bodies.

Rudis is the strongest available curative choice for Sclerotinia*.

*BCS trial: N. Yorks, 2008. Variety: Nairobi. Assessed as % area infected.

Alternaria control

To reduce Alternaria infection on the leaves, apply Nativo 75WG or Rudis early-mid August, or when first signs of disease appear on the foliage after the 5 true leaf stage of the crop (GS 15) if earlier than early-mid August.

Where curative activity against Alternaria leaf blight is required, mixing with an approved sticker/wetter adjuvant may enhance the activity of Nativo 75WG.

Resistance management

Nativo 75WG contains trifloxystrobin, a member of the Qol group. In accordance with FRAC guidelines for pre-mix Qol fungicides, the number of applications of Qol-containing products should be no more than 50% of the spray programme.

Rudis contains prothioconazole, a member of the DMI group.

Use Rudis and Nativo 75WG as part of an Integrated Crop Management (ICM) strategy incorporating other methods of control, including where appropriate other fungicides with a different mode of action.

Using Rudis fungicide as a Qualified Minor Use recommendation.

Rudis Qualified Minor Use

Rudis use on parsnips, swedes and turnips are Qualified Minor Use recommendations. There is limited evidence of crop safety and/or product efficacy and the commercial risk of using Rudis under these Qualified Minor Uses is borne entirely by the grower.

Application

Based on limited data Rudis will control leaf blight (Alternaria dauci), Sclerotinia rot* (Sclerotinia sclerotiorum), powdery mildew (Erysiphe heraclei) in parsnip and powdery mildew (Erysiphe cruciferarum) and Alternaria (Alternaria brassicae) in swedes and turnips.

*Moderate control.

Apply the first application before disease establishes itself in the crop. This should be followed by further doses at an interval of about 21 days.

Using Rudis in a programme with other preventative fungicides.

Example programme

No disease at T1

Application

Apply a preventative fungicide as the first application before disease establishes itself in the crop.  About 14 days later follow with a Rudis application.  Depending on the situation, you may need to use a block of two sprays at an interval of about 21 days.

Leek rust control

Whether for curative reasons or if the crop is very waxy, mixing Rudis with an approved sticker/wetter adjuvant may enhance activity.

White tip

To control, mix Rudis with a specific curative fungicide.

Note on Nativo 75WG

This product is no longer authorised for leeks, but work is ongoing to have it re-instated. Always check the CRD website for the latest product information.