Managing a fodder beet canopy is critical for a healthy and profitable forage crop. Autumn is the time to consider forming a disease control programme.

Supporting canopy retention through applying a registered fungicide has three main functions:

1. To reduce yield losses from foliar diseases.

2. Enhance plant growth through physiological benefits and green leaf retention.

3. Reduce frost damage by maintaining good crop foliage.

Ideally, two fungicide applications should be made 21 to 28 days apart. The first one should be applied at the first signs of any disease. It is important not to apply the first dose too early, or conversely, apply too late.

The main foliar diseases of beet are powdery mildew (Erysiphe betae), rust (Uromyces betae), Ramularia (Ramularia beticola) and Cercospora (Cercospora beticola). Climatic conditions are the main drivers for disease pressure and the biggest yield robber is Cercospora which thrives in warm, humid conditions above 25 degrees Celsius. Cercospora rapidly degrades the crop’s canopy and is often worse when a crop is also suffering from virus yellows. Unfortunately, we know that Cercospora is resistant to the current fungicide options available to farmers, though research is being conducted on finding a solution. In contrast, good control of the other foliar diseases can be achieved, and these diseases start to show themselves during autumn.

Brassica Integrated Pest Management

The continuing loss of plant protection products, increased resistance and Government policies encouraging less reliance on synthetic chemistries means that Integrated Pest Management is increasingly important.

Integrated Pest Management uses biological, cultural and selective chemistry control methods to cause maximum disruption to pest species while minimising disruption to beneficial species.

In brassicas, beneficial species like lacewings, ladybirds, hoverflies, and parasitic wasps prey on aphids and caterpillars. Little is gained from using a broad-spectrum insecticide that kills every insect in a crop. By doing so, the pest population increases sharply after the insecticide has run out of efficacy and before the beneficial species have time to recover. This negatively impacts the crop’s performance and ultimately reduces yields. A broad-spectrum insecticide is also harmful to bees and other pollinating insects.

Rather, choose a product that is beneficial insect-friendly. Before applying, check a portion of caterpillars to see if they have been parasitised by a wasp. If they have been, it may not be necessary to apply an insecticide, saving time and money.

Your local PGG Wrightson Technical Field Representative can monitor your crops and insect pest populations and recommend a suitable crop protection programme.