The 2021 iHemp Hour “Hemp Trials” episode featured one of the most detailed research updates ever shared on the show. University extension experts James DeDecker (Michigan State University) and Phil Alberti (University of Illinois Extension) presented brand-new data on grain, fiber, and CBD hemp performance across Michigan, Illinois, Wisconsin, and more.

For farmers planning the 2022 season—or anyone trying to understand what really works in Midwest hemp—this is essential information.

A Multi-State Research Collaboration

The Midwest hemp trials are part of a larger partnership between:

• Michigan State University Extension

• University of Illinois Extension

• UW–Madison

• Michael Fields Agricultural Institute

• Tribal research partners across Michigan

• Private labs supporting cannabinoid testing

This collaboration allows researchers to compare how the same genetics behave across different soils, climates, and management systems—something that never existed in the early years of the 2018 Farm Bill.

Michigan’s Tribal Research Initiative

James DeDecker also highlighted Michigan’s Hemp Tribal Research Initiative, which partners with:

• Bay Mills Community College

• Saginaw Chippewa Tribal College

• Little Traverse Bay Bands of Odawa Indians

The team tests CBD, grain, and fiber genetics while building long-term agricultural research capacity within tribal communities.

What the Researchers Found in 2021

The 2021 trials included:

• 5 site-years of CBD data

• 6 site-years of grain data

• The first dedicated fiber trials in Michigan

For anyone wondering which varieties are worth planting—or which ones are likely to go hot—this year’s results offered some surprising answers.

🌱 CBD Varieties: The 0.3% Problem Remains

Across the Midwest data set, 30% of CBD samples exceeded the legal THC limit.
Most varieties followed a predictable pattern:

Once CBD reaches ~8%, THC almost always crosses 0.3%.

Researchers repeatedly observed a stable CBD:THC ratio of 20:1 to 30:1, supporting detailed work from Cornell University.

This means:

• Genetics, not environment, primarily determine compliance

• Waiting too long to harvest dramatically increases risk

• Many popular CBD cultivars are genetically incapable of staying compliant past week 5–7 of flowering

Phil Alberti emphasized:

“By week seven, nearly every CBD variety we tested was going hot.”

CBG Varieties Stayed Safe

In contrast, none of the CBG-dominant varieties exceeded 0.3% THC, even late into flowering.

For growers worried about losing a crop to compliance violations, CBG genetics may offer a safer path.

🌾 Grain Varieties: Strong Yields… and Major Pest Pressure

Researchers evaluated 25 grain cultivars in 2021.

Key Findings

• Yields ranged from 125 to 1,400 lbs/acre, depending on location

• Larger seeds consistently produced better stands

• Establishing a target seeding rate (e.g., 25 plants/sq ft) often resulted in only ½ the desired stand

• Several new pests emerged, including:

  • Cannabis aphid

  • European corn borer

  • Corn earworm

  • Songbird grain depredation

  • White mold (Sclerotinia)—severe in 2021

White mold devastated many hemp sites—more than soybeans—illustrating how heavily timing and weather influence infection.

🧵 Fiber Varieties: European Genetics Show Promise

2021 was Michigan’s first dedicated fiber trial using European-born cultivars.

What Researchers Learned

• Fiber hemp was seeded at 50 plants/sq ft, but actual stands averaged only ~20 plants/sq ft

• European fiber varieties showed higher susceptibility to broadleaf herbicides

• Male plants remained present at harvest—ideal for fiber yield

• Retting (microbial breakdown of pectin between bast and hurd) resulted in significant dry-matter loss

• One fiber variety failed compliance, exceeding 0.3% THC

For processors investing in decortication and fiber lines, this data provides the first real comparison of genetic performance under Michigan conditions.

🧪 The Midwestern Hemp Database: A Game-Changer

The Midwestern Hemp Database (go.illinois.edu/hempdatabase) now contains:

• 1,381+ samples

• 159 unique cultivars

• 180+ grower cooperators

• Data from both university trials and real-world farms

This database helped influence USDA hemp regulations, including:

• Extending the harvest testing window

• Raising the negligence threshold from 0.5% to 1% THC

• Supporting research exemptions

A new Cultivar Check Program funded by SARE tested the region’s top genetics at three, five, and seven weeks after flowering. Results helped confirm:

• Stable CBD:THC ratios across locations

• Most CBD varieties exceeding compliance by week 7

• CBG varieties maintaining full compliance

• Environment affects cannabinoid quantity, but not ratio

Why This Research Matters

The Midwest hemp trials are building the foundation the industry desperately needed—real agronomic data, not marketing promises.

Growers now have answers to critical questions:

• Which varieties will stay compliant?

• When should I harvest?

• Which grain varieties withstand local disease pressure?

• How do European fiber genetics handle herbicides?

• What pests must be monitored?

• What seeding rates actually lead to viable stands?

Thanks to multi-state collaboration, the 2022 season will be the most informed year yet for Midwest hemp cultivation.