USDA’s Hemp Pollen Collector Turns a Backpack Vacuum Into a Breeding Tool

A backpack vacuum, a glass vial and a piece of fine mesh have become part of the USDA’s toolkit for preserving hemp genetics.

In a 2023 instructional video from the USDA Agricultural Research Service, Anthony Barraco demonstrates how to assemble and use a compact apparatus for collecting pollen from male hemp plants at the agency’s Plant Genetic Resources Unit in Geneva, New York. The setup resembles a Ghostbusters-style vacuum, but its purpose is practical: gathering clean pollen for breeding, germplasm conservation and research.

The collection system uses a spore-collection attachment connected to a vacuum, a glass vial and a 100-micron mesh screen. The operator places the nozzle near a male hemp inflorescence and gently collects the pollen as it is released. Hemp pollen grains are much smaller than the mesh openings, while larger pieces of leaves, flowers and other plant material are screened out.

The USDA has said the apparatus can collect as much as 10 grams of high-quality hemp pollen in less than a minute under suitable conditions. The agency’s published protocol, however, emphasizes that collection efficiency depends on the plant, the amount of available pollen and the condition of the mesh. As pollen and plant compounds accumulate, the screen can become clogged and reduce suction.

The procedure was developed to make pollen collection faster and more consistent. USDA’s protocol recommends replacing or shifting the mesh when suction declines, keeping collected pollen cool if it will not be used immediately, and cleaning and sterilizing the apparatus between plants or accessions to reduce cross-contamination.

Male plants are generally removed from fields grown for unfertilized flower because pollination can reduce flower quality and seedless production. In breeding programs, though, male plants are essential. Their pollen can be applied to selected female plants to produce seeds carrying particular traits, such as improved fiber, seed, cannabinoid or environmental performance.

The collection work is part of the USDA-ARS Plant Genetic Resources Unit’s broader effort to build and maintain a national hemp germplasm collection. The unit acquires, evaluates, conserves and distributes genetically diverse hemp materials to researchers, breeders and educators. Its hemp collection program identifies pollen collection as one of the tools needed to accelerate breeding and improve the management of hemp genetic resources.

USDA’s research project on conserving and using hemp genetic resources includes protocols for acquiring, regenerating, characterizing and distributing hemp accessions. The project’s annual report says the Geneva unit has also developed methods for hemp seed increase, pollen storage and pollen distribution.

The pollen apparatus is therefore less a farming gadget than a genebank tool. By making it easier to collect, preserve and share pollen from selected male plants, the USDA hopes to help researchers maintain genetic diversity and develop hemp varieties suited to future agricultural needs.

Hemp production remains subject to federal and state requirements. USDA’s official hemp resources page provides current information on licensing, sampling, testing and applicable regulations.