ECKART pigments for Seed Coating - Glistening delicacies

Seeds are highly perishable and therefore expensive. So farmers are very keen to protect their seeds from funqi, parasites and mould.

A coffee cup full of first-class tomato seeds can cost around US $10,000, which is about as expensive as pure gold. But the difference between the precious metal and these tiny seeds is that, if stored incorrectly, they can go bad and become unusable in a matter of days, meaning they will no longer germinate. Seed buyers expect maximum yield from the seeds they buy - the greater the number of seeds that germinate, the better value their investment has been. This rule applies to seeds across the board. including less valuable seed types that offen have to be stored in much larger quantities - which makes therm even more susceptible to going off.

It is hardly surprising, therefore, that researchers have been trying for a long time now to make seeds more resistant and last longer, in order to achieve optimum germination and growth rates. This perhaps brings genetic engineering to mind - which is not far off the mark, as researchers have been working with genetically modified seeds that are more resilient than natural seeds for a number of years now. But there is currently still a lack of knowledge concerning the effects of genetically modified plants on natural ecosystems.

But there is an alternative to genetic engineering, involving a highly unusual method originating in an industry sector that would appear to have little to do with agriculture. Plant seeds are extracted and made more resilient and more likely to germinate simply by coating them - it is the process of seed coating. This outer shell that is applied to the seeds can include all sorts of different ingredients, such as herbicides and fungicides or even fertiliser, creating the best possible germination environment for the seeds. Coating seeds in this way can increase the likelihood of a seed becoming a healthy shoot to around 98/99 per cent, and this is the main motive behind seed coating.

Another practical Solution is that of dyeing the seeds. The process of coating the seeds can change the seeds' size and shape to such a degree that it becomes difficult to differentiate between different seed types. After coating, rye seeds can look like wheat or oat seeds, for example - so by dyeing them different colours, identifying them becomes easier. Each seed type is ascribed its own colour.

And to widen the array of colours they can use, seed manufacturers add pearlescent pigments from ECKART to their coatings. The coating with its natural shimmer not only protects the seeds, but also makes them look fresh and healthy - after all, aesthetics play an important part in agriculture too.

It is fundamentally important that the ingredients of the seed coatings are as chemically neutral as possible. In other words, apart from the desired protective and fertilising effects, no other chemical activity should be initiated by any of the ingredients, especially any activity that would be harmful to the growth and overall health of the plant or that would pollute the soil.

"As a seed manufacturer, you have to be absolutely certain that you are not adding anything remotely toxic," explains Dr Mark Stoll, ECKART's Product Group Manager for pearlescence. When it comes to the ingredients in the seed coating, he is perfectly satisfied that ECKART's pearlescent pigments are not harmful, consisting primarily of mica, which is one of the most prevalent minerals in the natural world.

ECKART produces the pigments according to the seed manufacturers' requirements and delivers them as one of the numerous ingredients that go into the seed coatings. The seed manufacturers then attend to the actual coating process themselves. "We do know what the customer essentially does in the seed coating process, but we generally don't know the customer's formula," explains Dr Stoll. "We simply supply them with an easy-to-use ingredient that is neither toxic nor chemically active."

Interestingly, the pearlescent pigments used for seed coating are essentially the same as those used in the cosmetics industry. "There are no significant formulaic differences between the pearlescence in Shampoo and in seed coatings," says Dr Stoll, the only differences in the pigments are in the processing parameters, such as different pigment sizes, modifications to the surface (coatings) or providing a sterile form for sale.