Hemp Seed Quality – Risks and Potential Solutions

The farms ZS “Lojas” and SIA “Spelta” have been developing hemp cultivation and processing for many years. Since 2021, when the first hemp cultivar bred in Latvia, ‘Loja’, was officially registered, the farms have also initiated seed production of this variety, cultivating all seed multiplication categories. Such full-scale hemp seed production has never before been carried out in Latvia.
In 2024, the first larger batch of certified category C seeds of the variety ‘Loja’ was offered on the seed market. This was one of the reasons why the area under hemp cultivation in Latvia increased significantly in 2024 (according to data from the Rural Support Service – 830 ha in 2021 and 1,515 ha in 2024).
However, with the expansion of hemp cultivation areas, farms have faced new challenges. For the 2024 and 2025 harvests of ‘Loja’ hemp seed, very low germination rates have been identified, which complicates seed marketing, reduces income, and may negatively affect the volume and quality of subsequent harvests. In addition, farms have repeatedly encountered non-compliance of food hemp seed with food quality requirements, particularly in relation to yeast and mould parameters. To date, the exact cause of this problem is not clearly known.
Currently, possible hypotheses include fungal diseases or mechanical damage sustained during seed threshing and/or processing; however, other causes that have not yet been identified even theoretically cannot be excluded. The true cause could be identified through a scientific approach, by collecting and evaluating all relevant factors. A by-product of seed cleaning is also seed suitable for use as a food raw material, which is the main area of specialisation of SIA “Spelta”. However, there is currently no knowledge as to whether, with increasing disease intensity, seed contamination with mycotoxins may also increase, which is one of the key quality criteria.
Therefore, the project plans cooperation with researchers from the Institute of Horticulture, as the Institute has developed strong capacity in studies of the occurrence and diagnostics of plant pests and pathogens, while simultaneously expanding researchers’ knowledge and expertise. Consequently, implementation of the project will make it possible to identify scientifically justified causes of declining seed germination and quality parameters, to test potential solutions under production conditions, and to implement them in the technological production process.
Project objective
The objective of the project is, through cooperation between researchers, farmers, and agricultural product processors, to develop solutions for hemp cultivation and seed processing technologies to obtain high-quality hemp seed for the needs of seed production and the food sector.

Project tasks

1. To identify, under Latvian climatic conditions, the most important cultivation and technological seed processing factors affecting seed quality parameters for use in processing and/or seed production (germination capacity, infection with fungal diseases, contamination of seeds with mycotoxins).
2. Based on the identified factors, to conduct trials under production conditions aimed at improving hemp seed quality parameters.
3. By summarising the results, to develop solutions for hemp cultivation and seed processing technologies to obtain high-quality seed.

Main research directions of the project
During the project, research and activities will be carried out in two main directions:

1. Investigation of factors influencing hemp seed quality.
   Over three growing seasons, in four monitoring fields located in different regions of Latvia, comprehensive data will be collected on all stages of cultivation, harvesting, and seed preparation in order to identify the causes of deterioration in seed quality parameters. Researchers from the Institute of Horticulture will collect seed samples, isolate fungal pathogens, and conduct DNA analyses to accurately identify diseases present on hemp seeds in Latvia. In addition, analyses will be carried out for seed germination, mycotoxins (including ochratoxin, aflatoxins, and Alternaria toxins), as well as yeast and mould fungi. This research will allow conclusions to be drawn regarding possible improvements in cultivation and seed processing technologies to enhance seed quality.
2. Testing of solutions. Based on the results of the observations, in the second and third years of the project, production trials will be established alongside the currently used technology: one hemp field under an integrated cultivation system (ZS “Lojas”) and one field under an organic cultivation system (SIA “Spelta”). These trials will aim to identify technological approaches for improving seed quality parameters.

After completion of the project, the farms plan to implement the knowledge gained during the project in their production practices.