As someone who has been living and working in the seed treatment world, I have often heard the debate as to which is better: continuous treating or batch treating. In looking at the bigger picture, I don’t believe it’s an either-or scenario but rather a both-and, depending on the need and product being handled. Both methods apply treatments with accuracy and precision.
One thing we must keep in mind is that every farmer, regardless of location, is working to increase the efficiency of planting and tighten their planting window. To better understand each treatment system, let’s take a look and evaluate the capacity, accuracy, control and coverage of both.
The throughput capacity of a typical continuous treater is between 1,200-2,500 pounds per minute, whereas the typical batch treater would be 300-500 pounds per minute. Batch treating works well for a plant environment where time is not as much of an immediate issue, compared to the downstream seed treating that takes place at the retail / professional seed dealer level. The continuous treater is faster — there is no substitute for capacity and timeliness for downstream treaters.
When we look at the accuracy and control systems of each, both are accurate, but monitor and control the process differently. Batch treating takes longer, but it’s very accurate. Batch treating takes a measured amount of seed and a measured amount of treatment, and mixes them together for a specified time before discharging the treated seed (and then repeats the process for a new batch). Continuous treating is a more complex, “one-shot” process that simultaneously measures and adjusts seed flow and treatment flow throughout the course of the process and requires a high level of automation to get to the same level of accuracy.
Batch treating allows seed and treatment to mix for as long as desired or needed. For example, if a lot of treatment product is being applied, such as might be necessary with corn or cotton seed, extra drying time is needed, and batch treaters allow for that. Batch treaters also work well for seed surfaces where additional time results in better adhesion.
In continuous treating, seed flows through a two-step process where it is applied with treatment product in an atomizing chamber before advancing to a mixing process to achieve good coverage, usually inside a rolling, cylindrical drum. Continuous treating systems monitor both seed flow and liquid flow in real time. This requires immediate processing and control to quickly and accurately adjust the rate of either the seed flow or liquid flow and ensure that the treatment product is applied correctly on a per-seed or per-hundredweight basis; and all this has to happen as seed continuously flows through the process at 2,000 pounds per minute.
For most farmers, seed is one of their biggest investments. Farmers are paying more and more for seed singulation and every seed needs to germinate. Seed treatments play an important role, and it’s our responsibility to make sure this component isn’t a bottle neck for farmers. We’ve got to balance all these factors for the best outcome.
Remember: Both batch treaters and continuous treaters have a place, and accuracy is the end goal for both.