Oil rape seeds attract much attention for their nutritional properties. Not only from food manufacturers but from pests too. Aphids, beetles, moths, and a host of other insects all want a piece of the grower’s multiplication plot.
Seed protection treatments are formulated to repel attacks without harming non-target ecosystem elements.
However, variations in treatments mean wastage and discrepancies in the weight of consignments. More worryingly, they affect the growth cycle of rapeseed, leading to inconsistent harvesting.
Willem van Dok from Seed Processing Holland says that the treatment must cover 100% of the surface of the oil rape seeds. “The objective of growers is to obtain the highest yield for oil pressing, so exposed parts invite infestations and viruses.”
So the challenge is applying this treatment to a lot containing hundreds of seeds. “The main question for seed processing,” Willem notes, “Is how to coat every individual seed uniformly.” This becomes particularly tricky when working with treatments with a high liquid ratio.
But Seed Processing Holland doesn’t just pose the questions; it provides answers too. Willem explains how coating technology achieves homogeneous treatment at high speed.
Seeds are discharged in a rotary coating system and dried with dehumidified warm air. Simultaneously, the treatment mixture is pumped onto a spinning disc at the center of the system, distributing the coating evenly on the seeds as they revolve. During the seed treatment application, the seeds are dried and, when ready, discharged.
“We have pre-programmed this complex operation specifically for oilrape seeds,” says Willem, a solution to ensure homogeneity between lots and across batches.
A well-layered coating gives oilrape seeds their best chance to grow into seedlings. A fresh plot of foundation seeds is an open invitation to a banquet for pests, but precise treatment application closes the kitchen to them.