5th International Asparagus Cultivar Trial (IACT V) 
Invitation Letter
Dear Colleagues,
The 16th International Asparagus Symposium (IAS) in Iksan was a great success, and we remain sincerely grateful to our Korean hosts for their warm hospitality and thoughtful arrangements.
As one of the key outcomes of the symposium, we are pleased to announce the launch of the 5th International Asparagus Cultivar Trial (IACT V), proposed by Professor Guangyu Chen during the meeting. Building on the legacy of IACT I–IV, and after a hiatus of nearly nine years, IACT V will evaluate cultivar performance, yield stability, quality and stress tolerance across a wide range of global environments. Full details on seed supply and data sharing are set out in Part 2, General Principles of the 5th International Asparagus Cultivar Trial.
How to participate. Two short registration forms are provided in Part 3:
• Form A — Seed Provider Form — for institutions willing to contribute cultivars (commercial or breeding lines). Please state cultivar name, type, climate adaptation, spear emergence season, seed quantity per site, and the number of sites you can supply.
• Form B — Trial Site Form — for institutions willing to host trials. Please state site location, climate, area, maximum cultivar capacity, and your commitment to data quality and timely data sharing.
Deadline. Please complete and return the relevant form(s) to iact_v@jxaas.cn by 30 September 2026. We will then match seed supply with demand and issue detailed trial protocols to all confirmed participants.
We would also welcome contact details for asparagus breeders or seed companies in Spain, Canada, Chile, Mexico and other major asparagus-producing countries that were not represented at the 16th IAS.
We look forward to your participation. Please do not hesitate to contact us with any questions.
General Principles
1. Objective
To evaluate the agronomic performance, stability, quality traits and stress tolerance of asparagus cultivars from diverse breeding programs under a range of climatic and soil conditions worldwide, providing scientific evidence for international asparagus breeding and industry development.
2. Collaborative Mechanism
Participation is voluntary and open to researchers, breeders and extension specialists from all countries. Seeds are supplied free of charge by seed providers. Trial sites undertake to submit complete data to the Liaison Group, which will compile the results and share them with all participants, including the seed providers. Participants may withdraw at any time by giving prior notice to the Liaison Group.
3. Cultivar Entry
Entries may be commercial cultivars or advanced breeding lines, and must be clearly identified by name or code, origin and type.
The trial focuses on green asparagus, under both open-field and protected cultivation. White or purple asparagus must be declared and will be analyzed as a separate group, outside the main statistical analysis.
Checks follow a dual system:
(1) Universal checks (mandatory). Gijnlim F1 or Aspalim F1 is recommended for temperate and Mediterranean climates; Grande F1 or Atlas F1 for tropical and subtropical climates. Each site should include at least two universal checks.
(2) Local checks (encouraged). Sites may add one or two locally grown mainstream cultivars.
4. Trial Sites
Each site shall be located in a representative commercial or experimental asparagus production area. Sites should span the major ecological growing zones of the five continents to ensure broad ecological representativeness. Soil, climate, irrigation and management conditions must be documented in detail for each site.
5. Experimental Design
A randomized complete block design (RCBD) with at least three replications is recommended. Each site determines its own first harvest year according to local climatic conditions; this must be recorded accurately.
6. Seed Supply
Seed providers shall arrange international shipping themselves and send seeds directly to each trial site, following the demand list issued by the Liaison Group. As a neutral coordinator, the Liaison Group is responsible only for:
(1) recording seed supply intentions and cultivar lists; and
(2) matching supply with demand and notifying each provider of the corresponding shipping addresses.
The Liaison Group takes no part in transport operations and bears no costs or responsibilities relating to international shipping, customs clearance or phytosanitary procedures. Seed providers and trial sites are themselves responsible for ensuring that cross-border shipments comply with the phytosanitary regulations of both countries. At least 20 g (or 200 seeds) per cultivar, including checks, shall be supplied to each trial site to allow for planting and any replanting.
7. Data Collection
Standardized records shall be kept for emergence, fern growth, spear yield (early, total and marketable), spear quality (diameter, color, uniformity and tightness), disease incidence and pest damage. Observations on abiotic stress tolerance (drought, heat and cold) are encouraged.
8. Data Sharing and Publication
All trial sites agree to submit raw and summarized data to the Liaison Group. Results will be disseminated as follows:
(1) sites are encouraged to present their local results at the International Asparagus Symposium (IAS), as an oral presentation or a poster;
(2) sites are encouraged to submit their findings to Acta Horticulturae or another peer-reviewed journal.
9. Trial Duration
The trial cycle is synchronized with the International Asparagus Symposium (IAS) and spans five calendar years, from Year 0 to Year 4, matching the four-year interval between symposia. For the present cycle:
| Year | Calendar year | Main activity |
|---|---|---|
| Year 0 | 2026 | Launch of IACT V: registration, matching of seed supply and demand, seed shipment |
| Year 1 | 2027 | Sowing and transplanting (establishment year) |
| Year 2 | 2028 | First harvest year |
| Year 3 | 2029 | Full production |
| Year 4 | 2030 | Data compilation and final reporting; results presented at the 17th IAS |
The actual first harvest year may differ between sites according to local climatic conditions and must be recorded accurately (see Section 5).
10. Coordination Mechanism
An IACT V Liaison Group will be established to facilitate communication among trial sites, oversee consistent implementation of the protocol, and collect, validate and compile the data.
11. Funding and Costs
Each participating institution bears its own local costs, including land, labor, materials, seed import and phytosanitary clearance, and analysis. No entry fee is charged, but participants are encouraged to seek local or national funding to support their involvement.