Processing of seed cereals

At Semenarna Ljubljana, we can produce seeds which meet or even surpass all European standards. Inspired by the tradition of processing and packing, as well as our desire to provide our customer with top-quality seeds, we established the modern Ptuj Selection Centre in 1968.


Semenarna Ljubljana has been producing its own seed cereals and other seeds for almost 110 years. In Slovenia, production is organised with private persons, on agricultural estates, and on the Selection Testing Centre of Semenarna Ljubljana in Ptuj. Due to the seed-producing tradition in Slovenia we can be proud of the fact that our producers have met all the criteria for a quality seed production at the technological level.

In continuation, we are presenting the procedure for acceptance and processing of seeds following quality production in the field which we perform using our own knowledge and technological equipment.

The acceptance of natural seeds
At harvest time, the collection of natural seed, i.e. seed grown, is organised at the Semenarna Ljubljana facility for seed processing in Celje. The location in Celje is favourable from the logistics and marketing points of view, because it is situated in the central part of Slovenia near major traffic routes.

Seed sampling
Upon collection, the sampling of seeds is performed first, and at the same time, the routine measurement of the balanced relative seed moisture using a digital electronic instrument. In this way, we avoid collection of overly moist seeds in the processing procedure.

A properly taken sample is a prerequisite for the credibility of the analysis results. The sample of seeds must be representative meaning that it must represent the average quality of the entire seed lot sampled. Samples prepared in this way are equipped with all the required data (species, variety, supplier, weight, lot number) andsent to the Laboratory for Seed Quality Control at the Agricultural Institute in Ljubljana.

Laboratory analysis of seeds
An analysis of seed quality are performed for each seed lot at the laboratory. The quality of agricultural plant seeds is tested under optimal conditions for each plant species separately, and according to the procedures prescribed for seed testing by the International Seed Testing Association.

First a Quality-at-Entry analysis is performed. This is the analysis of the natural seed or seed as grown. It is composed of individual tests where the moisture, purity, energy, germination and health conditions of the seeds are determined.

Seed processing procedure

The aim of the seed processing procedure is to obtain quality, healthy seeds with appropriate purity, moisture and germination properties. The results of the Quality-at-Entry analysis represent the basis for the decision of technologists regarding the method for processing a certain seed lot. The most important data are the seed moisture and purity, therefore these tests are done as soon as samples arrive to the laboratory. In this way, we can decide if additional drying is necessary or what kind of machines will be used for cleaning the seeds. Based on the analysis of the health condition of the seeds, an adequate disinfectant is selected.

All seeds placed on the market must comply with the norms prescribed by Slovenian legislation, otherwise, they are not suitable for packing and placement on the market. The quality norms are laid down for each plant species separately. The technologist decides for the type of processing procedure of seeds of a corresponding quality based on the established analysis of natural seeds.

Description of the seed processing mechanical equipment at the Production unit Celje
The basic parts of the seed processing mechanical equipment are the following:

  • Husker: dehusking of the whole or a part of the ears and individual unhusked seeds. This operation facilitates the work of machines which follow and play a decisive role in the quality of the final product.
  • Pre-selector: rough pre-cleaning of seeds whereby seeds are separated from the dust, rough impurities, and bigger seeds of other plant species (weeds).
  • Fine selector: fine cleaning of seeds where small fractions are separated from the sieves on the machine.
  • Trier: separation of the seeds based on shape and size. It is composed of two sequentially connected cylinders; the first one seperates seeds that are too long from the clean fraction while the second one  seperates small grained impurities, weeds, and crushed grains.
  • Gravitation table (separator): the seeds that arrive at the table are uniform in shape and weight, so that here the seeds are separated on the basis of their specific weight. During this procedure, quality seeds of normal specific weight are separated from specifically lighter seeds which are affected due to diseases, pests, or inadequate maturity level due to excess moisture or a too dry harvest.
  • Disinfection machine: surface treatment of the seeds with fungicides and insecticides. It is adjusted to the use of liquid or powder substances and has a closed vacuum system which prevents the emission of the disinfection substances into the environment.
  • Automatic electronic net packing scales: packing of seeds of different net weights into natron bags.
  • Dust aspiration:
    • on the disinfection machine: for the suction of aerosol of the disinfection substances, so that they do not escape into the environment.
    • central: for the prevention of dust emissions in the open strewing of seeds. It is performed on elevators, trier, package scales, gravitation table, and selectors.

Once the seeds are processed (dried, cleaned and disinfected), samples are taken again from each lot of the clean (processed) seeds, following which the final quality analysis (composed of the same tests as the Quality-at-Entry analysis) is performed which serves as the basis for issuing the quality declaration or quality certificate.