History of International Nurseries

In the 1950s a stem rust epidemic attacked wheat in the USA and Canada. About 60% of the wheat harvest in the US was destroyed in 1953, and about 75% in 1954. The culprit was a new pathogenic race called 15B, which was resistant to all genes present in existing commercial varieties. A similar race spread widely in Latin America. In response to the epidemic, the US Department of Agriculture requested that seven nations (Mexico, Colombia, Ecuador, Peru, Chile, Argentina, and Canada) join forces in testing 1000 lines selected from the wheat world collection.

The Office for Special Studies, CIMMYT's predecessor, was an active participant in the effort, and new lines of wheat were exposed to stem rust in Mexico. The results of the First International Stem Rust Trial exceeded all expectations. New sources of resistance were found for the 15B race, some of which may still be present in commercial varieties today. An added benefit of this trial was the creation of a network through which lines and introductions could be tested and distributed to developing countries.

In 1960 the first international spring wheat yield nursery was distributed by the Office for Special Studies to 12 countries from Canada to Argentina. In response to the expressed interest of other wheat-producing countries around the world, in 1964 CIMMYT created the International Spring Wheat Yield Nursery (ISWYN) that included lines adapted to high and low latitudes.

In 2001, the International Wheat Improvement Network (IWIN) at CIMMYT prepared 2,766 sets of 40 different bread wheat, durum wheat, triticale, and barley nurseries. Seed shipments were sent to a network of 619 wheat scientists from 117 countries around the world.

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