Developing new seed treatments with biologicals is not that simple. Not all biological agents are just suitable for seed treatment. To make the seed treatment process feasible, the particle size of the material containing the spores of the agent should be very small. Furthermore a high CFU count is needed (CFU = Colony Forming Unit) and the material can not be contaminated with other microorganisms. For long term survival the biological also needs to be desiccation-tolerant.

Extensive research and selection of the right antagonist is needed to come to a new biological seed treatment. A number of tests are available at Incotec to enable us to come to the most efficient combination of seed, biological and application method. We strive after all for a product with the most optimal field performance.

Tests that are used during the research phase include:

• CFU count:

By standard dilution plating of the used formulation, the number of colony forming units can easily be determined. We analyze this before and after the coating process. In this way we can measure the survival of the biological during our coating process. With this test we can also examine the shelf life of the biological agent after it is coated on the seeds.

• Bioassay:

• Root colonization tests:

Plants are grown in the greenhouse on specific potting mixtures. After a certain period the roots are harvested and almost all the potting mix is removed. With dilution plating the amount of spores (cfu’s) can be determined per gram of root tissue. The cfu count gives you information about the ability of a biological to grow with the root system. Besides this quantitative test we also can test the presence of the biological on the roots by putting different parts of the roots on plate.

• Compatibility tests:

For biological seed treatments it is very important to know which pesticides are compatible with the beneficial microorganism coated on the seeds. Using in vitro growth tests we can determine which pesticides can be used in combination with biologicals.

• Coating trials:

Biologicals are living organisms that are very vulnerable, even when they are in a dry quiescent state. During the coating process the spores are physiologically activated because of the presence of water. After the coating process the treated seeds are dried, including the spores. They are returned into their dry quiescent state. By optimization of the coating process the viability of the spores can be maintained on a very high level.

Finally our biological seed treatment is tested in the greenhouse and in field trials. Yield measurements are made to analyze the economical value of our biological seed treatment.