Study of methods to reduce the influence of surface tension force during flotation of coniferous seeds

When harvesting coniferous seeds, it is necessary to separate them into empty and full-grained seeds. One of the methods for separating empty seeds from full-grained seeds is seed flotation. Seed flotation is used to sort seeds in liquid based on their density. The disadvantage of this method of determining the fullness of seeds is the duration of soaking. To neutralize the surface tension force during seed flotation, we proposed the use of a mixing device (Biosan OS-10 rotator) and the use of surfactants (diethyl ether). There is very little data available on seed flotation in general, and no data on the effect of diethyl ether on the flotation time in particular. The objects of the study were Scots pine, European spruce, and Siberian, Daurian, and European larch. The results of the study show that the use of various methods for reducing surface tension accelerates the flotation process. However, there is currently no universal "ideal" approach with an optimal solution and soaking time that is suitable for the effective flotation of seeds from all coniferous forest-forming species in Russia. Even the Siberian, European, and Daurian larch species, which belong to the same genus, behave differently when soaked in water. The flotation method should be specific to each individual species, both when using a rotator and when using surfactants. The study provides recommendations for conducting flotation for each species under investigation.