Since early 1960s, the international multilocation testing of experimental germplasm has become widely accepted as a viable approach to accelerating the germplasm improvement process. In the case of wheat and triticale, CIMMYT serves as the hub of one of the world's largest international testing networks - The International Wheat Improvement Network (IWIN); several hundred voluntarily cooperating agricultural scientists from both public and private sectors, located in over 100 countries worldwide, participate in the evaluation of experimental wheat materials contained in CIMMYT nurseries.

Spring bread and durum wheat, and triticale nurseries are distributed from CIMMYT in Mexico. Winter and facultative bread wheat nurseries are distributed by the TURKEY/CIMMYT/ICARDA International Winter Wheat Improvement Program. Collaborative regional trials are also distributed from Central Asia, Siberia and the Eastern Gangetic Plains, and for specially targeted experimental probe experiments.

These nurseries are grown under a wide range of environmental conditions, and are subjected to numerous diseases and other stresses. How does it work?

  • Improved wheat germplasm is dispatched, through nurseries targeted to specific agro-ecological environments, to this network of researchers.
  • Data from these trials are then returned to CIMMYT, catalogued, analyzed and made available to the global wheat improvement community [access IWIN data].
  • The ultimate beneficiaries of the fruits of this network are farmers who will receive improved bread wheat, durum wheat and triticale varieties.

Accuracy in recording performance data and its timely return to CIMMYT for analysis are critical to the success of the international testing network. Data from many researchers are fed into the system, and the pooled results form the basis of the international nursery data and reports made available by CIMMYT. The quality of these nursery reports is totally dependent upon the quality of the experiments and the data reported by each cooperator. The reports help guide subsequent breeding efforts, both by CIMMYT and by cooperating wheat researchers around the world.

CIMMYT assembles and distributes four basic types of international nurseries:

  • Yield trials
  • Screening nurseries
  • Segregating populations

If you want to search by nursery check the list of nursery abbreviations.

Please note that below list is a complete list of IWIN nurseries. Not all these nurseries are included in the Wheat Atlas database.

Bread Wheat Nurseries - Spring Wheat
ASWSN Acid-Soils Wheat Screening Nursery
EBWYT Elite Bread Wheat Yield Trial
ESWYT Elite Spring Wheat Yield Trial - grain color = WHITE
  • ESWYT-CHN (special edition for China)
HLAYT High Latitude Adaptation Yield Trial
HLWSN High Latitude Wheat Screening Nursery
HRWSN High Rainfall Wheat Screening Nursery - grain color = RED
HRWYT High-Rainfall Wheat Yield Trial - grain color = RED
  • HRWYT-CHN (special edition for China)
HTWSN Heat Tolerance Wheat Screening Nursery
HTWYT High Temperature Wheat Yield Trial
  • HTWYT-CHN (special edition for China)
IBWSN International Bread Wheat Screening Nursery (for irrigated conditions) - grain color = WHITE
  • IBSWN-CH (special edition for China)
ISWSN International Spring Wheat Screening Nursery
SATYN Stress Adaptive Trait Yield Nursery
SAWSN Semi-Arid Wheat Screening Nursery(for low rainfall conditions) - grain color = WHITE
SAWYT Semi-Arid Wheat Yield Trial
WAWSN Warmer Areas Wheat Screening Nursery
Bread Wheat Nurseries - Facultative and Winter Wheat
FAWWON-IR Facultative and Winter Wheat Observation Nursery for Irrigated Environments
FAWWON-SA Facultative and Winter Wheat Observation Nursery for Semi-Arid Environments
IWWYT-IR International Winter Wheat Yield Trial for Irrigated Environments
IWWYT-SA International Winter Wheat Yield Trial for Irrigated Environments
WWSRRN Winter Wheat Stem Rust Resistance Nursery
Durum Wheat Nurseries
EDUYT Elite Durum Yield Trial, unreplicated
IDSN International Durum Screening Nursery
IDYN International Durum Yield Nursery
Triticale Nurseries
FWTCL Facultative and Winter Triticale
ITYN International Triticale Yield Nursery
ITSN International Triticale Screening Nursery
Special and Project - Specific Nurseries
CSISAHT CSISA Heat Trial (CSISA = Cereal Systems Initiative for South Asia)
CSISASB CSISA Spot Blotch (CSISA = Cereal Systems Initiative for South Asia)
FHBSN Fusarium Head Blight Screening Nursery (earlier Scab Resistance Screening Nursery - SRSN)
GAWYT Global Adaptation Wheat Yield Trial
HPYT Harvest Plus Yield Trial
HPSAN Harvest Plus South Asia Nursery
IAT International Adaptation Trial
ISEPTON International Septoria Observation Nursery (earlier Septoria Monitoring Nursery – SMN)
KBSN Karnal Bunt Screening Nursery
SMN Septoria Monitoring Nursery (now International Septoria Observation Nursery – ISEPTON)
SRSN Scab Resistance Screening Nursery (now Fusarium Head Blight Screening Nursery)
STEMRRSN Stem Rust Resistance Screening Nursery
WYCYT Wheat Yield Consortium Yield Trial