Crop Variety Trials

Changing climates and political situations drive a need to adapt the way we feed the world. BioSS works with partners worldwide to improve methodologies used to select optimal plant varieties for our changing environments.

Our crop variety trials work is split into these main areas:

DUS testing

All crops are assessed for Distinctness, Uniformity and Stability (DUS) to protect the rights associated with registered varieties:

  • Distinctness: is the variety markedly different from existing registered varieties?
  • Uniformity: do all plants of the variety look the same?
  • Stability: does the variety look the same over multiple generations?

In some crops, trial sizes can be very large due to the need to compare candidate varieties against all existing varieties. DNA fingerprints can be used to reduce the number of varieties that a candidate needs to be compared against, and thereby reduce costs.

Performance Testing

  • Performance testing for all agricultural crops (other crops are only tested for plant breeders’ rights).
  • Requirement to allow marketing of a new variety: 2 or more years of Value for Cultivation and Use (VCU) testing
  • Further Recommended List testing provides information for growers on optimal varieties for their locations: up to 3 more years of VCU testing
  • Varieties are tested for yield output, disease resistance and other agronomic characters
different varieties of kale growing in a field

INVITE Project

BioSS is working with 29 partners from over Europe to improve both the efficiency of variety testing and the information available to stakeholders on variety performance under a range of production conditions and biotic and abiotic stresses.

Role of BioSS:

  • Statistical aspects of variety testing
  • New methods using high density DNA markers for more effective distinctness assessment
  • Performance (VCU): introduction of DNA markers into better statistical models


Current projects:

  • Shading in winter barley trials: taller varieties stunt the yields of neighbouring shorter varieties. Mitigation strategy identified and will be in place from sowing 2023.
  • Spatial variation in variety trials: investigating the extent of underlying spatial variation in trials and ways to model this.
  • Improving prediction of variety performance in future years by modelling variety as a random rather than fixed effect.
  • An improved method for assessing the uniformity of new varieties.
Trees icon

Main contributors to this area: