Evaluation location: Kentucky, United States
Hemp germplasm project 2025 summary
The hemp germplasm was established at the University of Kentucky Spindletop Research Farm (Lat: 38.13° Long: 84.50°; elevation 285.3m) for the 2025 field rating/screening year.
The hemp accessions were grown from seeds in the greenhouse and transplanted into the field on 10 July 2025.
In total, approximately 17% of the plants were male, 10% were monoecious and the rest were female.
The first incidence of Fusarium head blight (FHB) observed on the hemp germplasm was in the first week of October. Disease incidence continued to increase until mid-November, when temperatures dropped to -0.5ᵒC. Mostly the female plants had FHB and a few monoecious, no FHB was observed on the male plants. Rating continued until plants senescence
Typically, FHB in hemp develops and spreads with a combination of warm temperatures, between 230C and 300C and high moisture or continuous high humidity (greater than 90%) for an extended period.
Consequently, the delayed FHB incidence experience on the field is perhaps due to high temperature and low humidity/precipitation experienced in preceding months to October.
In October, the average temperature was 14ᵒC and total precipitation was 20.6cm. The highest temperature was 28ᵒC, and the lowest temperature was 1ᵒC. In November, the average mean temperature was 8ᵒC, and total precipitation was 6.4cm. The highest temperature was 22ᵒC and the lowest temperature was -7ᵒC.
In general, FHB incidence ranged from 10% -70%. Hemp that had FHB included accessions: Bubba, BADGAR 1, BADGAR 5A, Blue Kross, CAN 24, CAN 36, CAN 29, Carmagnola, Carolina Dream, Cherry, Cherry x # 5, Dongma, Fibror 79, First Class ‘CBG’ S1, HAN-NW, HCP 040, HT Seed-04, Original Cherry, PI-32-15, RN17, RNF x RNF-STS, SAS_CHECK_10, THCV x Syrian, Zhongma, #4, and 7/6-19_SGS.
However, a few were exceptionally susceptible among others. Hemp accessions PI-32-15 reached 70% disease incidence while BADGAR 5A, Bubba, CAN 24 and RN17 reached 50% FHB incidence.