Disease Focus: Key Spring Diseases in OSR and How to Manage Them!

Maintaining a healthy crop canopy in spring is essential for maximising green leaf area and light penetration as crops approach the critical flowering stage.

Problem diseases to watch out for in the spring…

Light Leaf Spot Focus

Light Leaf Spot can continue to spread in the spring, often carrying over from autumn infections, especially in mild, wet conditions or where earlier fungicide timings were missed. Left untreated, it can severely impact leaves, stems, flowers and pods, causing significant yield losses.

Light leaf spot can continue to spread in the spring, often spreading from infections that began in the previous autumn. Left untreated, it can severely impact leaves, stems, flowers and pods, causing significant yield losses.

• Carry-over from autumn infections.
• Affects leaves, stems, flowers and pods.
• Risk: High in mild, wet springs or where autumn sprays were missed.

Applying follow-up fungicide sprays in the early spring period provides an important last timing slot to control the disease or minimise further yield damage caused.

Product options:

• Clayton Tuskar™ – 250g/L prothioconazole (moderate control)
• Clayton Navaro™ – 125g/L prothioconazole + 125g/L tebuconazole (reduction of disease)
• Clayton Tebucon 250 EW™ – 250g/L tebuconazole (supportive control)

Sclerotinia Stem Rot

Sclerotinia stem rot poses another spring risk, a soil-borne disease that infects at flowering and can lead to premature ripening, lodging, and serious yield losses. Conditions during mid-to-late spring often favour its development, making timely applications critical.

Sclerotinia stem rot poses another spring risk, potentially leading to premature ripening, higher risk of lodging and associated yield losses. Infects plants at flowering. Causes premature ripening, lodging and yield loss. Targeted fungicide applications during mid to late spring are essential for effective control of this damaging soil-borne disease

Product options:

• Clayton Augusta™ – 250g/L azoxystrobin (moderate control)
• Clayton Tuskar™ – 250g/L prothioconazole (control)
• Clayton Navaro™ – prothioconazole + tebuconazole (control)
• Clayton Tebucon 250 EW™ – tebuconazole (supportive control)

Other Spring & Early Summer Diseases

Alternaria (Dark Leaf Spot / Pod Spot):

Affects pods, seeds, and the upper canopy. Can lead to pod shatter and reduced seed quality, especially later in the season.

Other spring and early summer diseases, including Alternaria (dark leaf spot/pod spot) and Ringspot, may also need to be managed with appropriate fungicide choices.

• Alternaria affects pods, seeds and upper canopy. Can cause pod shatter and lower seed quality.
• Ringspot occurs less frequently but favoured by humid springs. Affects leaves and pods.

Proactive assessment and early identification of crops at risk of disease are key to ensuring timely and effective applications to achieve the best results.

Product options:

• Clayton Augusta™ – azoxystrobin
• Clayton Tebucon 250 EW™ – tebuconazole

Ringspot:

Less common, but it can occur in humid spring conditions. Affects leaves and pods, with the potential to disrupt pod development.

Product options:

• Clayton Tebucon 250 EW™ – tebuconazole

Please take a look at our latest OSR Fungicides Product Range below:

Need help with disease control in OSR?

For further information on products in this update and our full product range, get in touch with our Technical Team:

Will Ridgwell – Commercial Manager – will@claytonpp.com
Martyn Rogers – Product Development Manager – martyn@claytonpp.com

Information in this update does not constitute a recommendation; it is for guidance only. Detailed information about our products can be found on our website. Brand names used in this update are trademarks of Clayton Plant Protection. Use plant protection products safely. Always read the label and product information before use.