This week's Hemp Show is the second episode of our four-part miniseries covering the 2026 USDA Hemp Stakeholder Event, which took place at Cornell AgriTech on September 10. In Episode 1, we looked at the diversity inside the national hemp germplasm collection. In this episode, we turn to measuring it: hemp DNA, hemp seed, hemp stems and THC. Dongyan Zhao of Breeding Insight, a USDA-ARS program hosted at Cornell, explains a new public genotyping panel that checks about 3,000 genetic markers for roughly $15 a sample. It can confirm a plant's genetic sex before a breeder makes a cross, and it shows that two seed lots with the same variety name aren't always the same seed. Roque Evangelista, a research chemist with the USDA-ARS Bio-Oils Research Unit in Peoria, Illinois, shares seed weight, oil, protein and fatty acid data from hundreds of accessions in the collection, now public in GRIN-Global, and shows how density grading can sort one harvest into seed, hemp hearts, oil and feed. Wayne Swink of the USDA-ARS Cotton Quality and Innovation Research Unit in New Orleans talks about a small decorticator built to measure how much force and energy it takes to break hemp stems, and why fiber is still one of the hardest things about hemp to measure. Finally, Korey Brownstein, a research chemist at the same Peoria research center, describes his open-source method for rapidly measuring 20 cannabinoids, and the problem it's meant to solve. "Lab to lab variation is a very real situation that we are dealing with, right?" he said. Next time, in Episode 3, we'll turn to disease: a fungus that moves between wheat and hemp, a growth chamber full of sick plants, and a disease-resistance gene from a plant most farmers would have mowed down. Learn More Breeding Insight, Cornell University breedinginsight.org Roque Evangelista, USDA-ARS Bio-Oils Research Unit ars.usda.gov Wayne Swink, Fiber Quality Analysis Webinar, Cornell Hemp hemp.cals.cornell.edu Korey Brownstein, USDA-ARS Functional Foods Research Unit ars.usda.gov NIST Cannabis Quality Assurance Program nist.gov National Plant Germplasm System ars-grin.gov USDA ARS Hemp Webinar Series ars.usda.gov Cornell Hemp hemp.cals.cornell.edu Thanks to Our Sponsors Jungmaven jungmaven.com Condor Seed condorseed.com IND Hemp indhemp.com Forever Green, KP4 Hemp Cutter hempcutter.com The Lancaster Farming Industrial Hemp Podcast, also known as The Hemp Show, continues its four-part miniseries on the 2026 USDA Hemp Stakeholder Event, held September 10, 2026, at Cornell AgriTech in Geneva, New York. Hosted by the USDA Agricultural Research Service (ARS) Plant Genetic Resources Unit, the meeting centered on the national hemp germplasm collection, a public seed bank of Cannabis sativa that is part of the National Plant Germplasm System (NPGS). Episode 2, "Measure It," covers the tools hemp breeders, growers and processors need to put that genetic diversity to work: hemp genotyping, hemp seed composition analysis, hemp fiber testing and THC testing. Using recordings of the day's presentations, the episode features researchers from Breeding Insight at Cornell University and from USDA ARS laboratories in Peoria, Illinois, and New Orleans. Dongyan Zhao of Breeding Insight, a USDA ARS initiative hosted at Cornell, presents a public mid-density hemp genotyping panel developed with the Plant Genetic Resources Unit in Geneva. The DArTag panel, run through Diversity Arrays Technology in Australia, targets about 3,000 marker loci, returns results in about four weeks and costs about $15 a sample plus DNA extraction. Development costs were covered up front, so breeders pay only for genotyping. Hemp geneticist George Stack selected the markers with input from stakeholders. Replicated samples agree more than 99% of the time, but different seed lots of the same accession matched only about 83%, showing the genetic diversity within hemp accessions and the risk of mislabeled parental lines. The panel also confirms karyotypic sex, identifying XX mother plants for crosses, and supports population structure and pedigree analysis, marker-assisted selection, QTL mapping and genomic prediction. Roque Evangelista, a research chemist with the USDA ARS Bio-Oils Research Unit at the National Center for Agricultural Utilization Research in Peoria, analyzed more than 300 and then another 380 hemp seed samples from the collection for seed weight, oil content, protein content and fatty acid profile. That hemp seed data is now public in GRIN-Global. Asian accessions produced the largest seeds and somewhat higher oil, but large-seeded plants appear across gene pools, and Evangelista keeps extreme outliers in the data because breeders may be looking for them. Because hemp is indeterminate, harvested grain varies in maturity. Density grading separated heavy, mature seed, about 74% of one lot, from light seed with much lower oil but similar protein, which could go to seed companies, hemp hearts, oil pressing or feed. He also covers cold-pressed hemp seed oil, residual oil in press cake and near-infrared (NIR) calibrations for oil, protein and fatty acids. Wayne Swink of the USDA ARS Cotton Quality and Innovation Research Unit in New Orleans is linking hemp fiber traits to the DNA sequencing of the collection. His team built a bench-scale hemp decorticator, with a pneumatic actuator, a load sensor and a four-roller conditioner, that measures stem breaking force, energy demand and biomass balance between bast fiber and hurd. First data covered 15 stems, and true fiber quality testing is still ahead. Korey Brownstein, a research chemist at the Peoria center, presents a rapid, open-source method for 20 cannabinoids, including THCA, Delta-8 THC, CBGA and CBG, that avoids heat, uses ethanol extraction and sonication and handles about 100 samples a day. He took part in a NIST interlaboratory study and explains why total THC testing near the 0.3% legal limit, and the 2 ppm THC limit for hemp seed meal in laying hen feed, depends on which lab runs the sample. Episode 3 of the USDA hemp series turns to hemp disease.