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Bayer Assist

For friendly informed advice about Bayer CropScience products, please call Bayer Assist free from UK landlines on:

0845 6092266

Alternatively, call us on:
01223 226644

(0900-1715 weekdays)

Cereal Fungicides 

Proline on Sclerotinia  

Proline on Sclerotinia


[Proline on flowering OSR]  [Canopy Management]  [Alternaria]  [Light Leaf Spot]


In most seasons Sclerotinia spore germination coincides with early to mid flowering of oilseed rape.  The Sclerotinia spores infect petals when wet weather occurs during the flowering period. Where the petals fall into the crop and stick to the stem, spores germinate on the petals and then attack the stem, leading to reduction of nutrient transfer up the plant, green tissue area loss and lodging. As all fungicides are protectant, sprays applied immediately prior to infection will be most effective.

2007 - Robust rates of Proline applied early or mid-flower treatments just prior to infection gave the best results. 

Data Source: Bayer CropScience 2007. Sclerotinia timing trial Romney Marsh, Kent Untreated Yield 2.95t/ha. Untreated Sclerotinia 42% plants infected Variety: Castille. Applications 22/3, 11/4 & 21/4


In 2007 some regions of the UK suffered their worst Sclerotinia outbreaks for many years.  This was due to the unusual weather patterns which created the ideal conditions for infection.

While it was obvious to most that the large area of OSR grown in the UK and the tight rotations used would create a high level of potential Sclerotinia infection, the dry April and early flowering of the crop did not trigger concerns about an epidemic.

In reality however, the heavy dew caused by the huge temperature fluctuations in April encouraged early Sclerotinia germination and infection of the crop.  The rains during mid to late flowering then gave the perfect conditions for a damaging disease epidemic; with severe yield losses in many crops which were not treated with a fungicide.

Proline has proven to be the most effective and persistent of the flowering treatments for OSR, and with the move towards spraying crops at yellow bud stage to prevent damage to the crop if sprayed when taller at flowering, that persistence is valuable.

2007 - with prolonged infection periods, Proline's persistence paid off.


Data Source: Bayer CropScience 2007 2 trials Westwell, Oxon Untreated Sclerotinia 76% stems infected at harvest. Yield 3.27 t/ha Excalibur assessed 106 DAA

There has been much debate on whether fungicide use can increase oil content of OSR, and while consistent effects are hard to find, there is a link between yield and oil content - basically the higher the yield, the better the oil content, so by using Proline to maximise yield you will have a beneficial effect on oil content.

Oil content increases with yield

Data Source: ADAS trial Rosemaund 2007