PT303

PT303 Protector® Sclerotinia maintains high position on the 2023 AHDB UK Recommended List

Pioneer's Winter Oilseed Rape hybrid with tolerance to Sclerotinia which achieved top position on the ADHB 2022 UK Recommended List has maintained a high position on the new 2023 UK Recommended List.

PT303 has consistently given top yields across multiple trial programs and provides tolerance to a disease that is associated with high rainfall events often experienced in the UK. PT303 also combines proven TuYV resistance and multigenic Phoma resistance for a powerful overall disease resistance rating.

Sclerotinia 

Sclerotinia is a soil-borne fungal pathogen, which can remain viable in the soil for up to 8 years. A single sclerotium produces 10 – 14 apothecia which in turn produce 10 – 14 million spores and it can affect many crops, including: Oilseed rape, Peas, Beans, Lucerne, Carrots and Potatoes (>400 host species).

Sclerotinia is usually the main disease to impact OSR at the important flowering stage and in severe infections the yield impact can be >50%! Although epidemics are uncommon, localised infections occur most years and the inoculum burden continue to build if infections are not controlled. 

There are three main factors required for the infection cycle to take hold in OSR (as illustrated in the graphic below):  

•       Presence of sclerotinia fungal resting bodies (Sclerotia) in the soil which germinate when soils are moist and >10°C
  
  
•       Favourable weather conditions, long periods (>23hrs) of relative humidity >80% & air temperatures >7°C (day & night)
  
  
•       Crops to be in flower, providing spores with external nutrients needed for germination

Most sprays offer approximately three weeks control; therefore, two sprays are often required to cover most of the flowering period. (Although flowering can last circa 8 weeks). Fungicide efficacy may be limited as new flowers will form during the flowering period that will not be protected by previous applications. 

PT303 has a unique native multi-genic sclerotinia tolerance trait. By sowing PT303 in 2021 growers can incorporate a level of tolerance to sclerotinia for the first time into their crop management planning.