Frankfurt am Main, Germany, August 24, 2018—Planting seed potatoes has developed into a highly complex step in cultivating the crop. In addition to having to handle a comparatively large amount of seed—an average 2.5 tonnes/hectare—farmers have to manage seed bed preparation and fertilizer applications, and the process might also include treatment against seed- and soil-borne pests and terminal ridge formation.
However, the basic task of potato planting is still to place the tubers in the ground, the correct way up, at a constant depth and in a uniform pattern that may see the distance between the tubers change depending on the different utilization of the harvested crop. The furrow openers—guided, for example, by gauge wheels that manage their depth—in front of the planting units form a wedge-shaped gutter that is intended to counteract rolling of the deposited tubers. Individual potato plants have a very large compensation capacity that allows them to react to different conditions during growing and allows them to change the number and size of tubers, but this is not desirable due to the market’s increasing desire for a uniform crop.
To optimize the marketable yield, farms must first vary the distance between the planted seed potatoes based on the soil quality as recorded for a number of different parameters. Several years of research has confirmed in potatoes the well-known principle seen in other crops, that by planting the tubers further apart in an area of a field where the soil is lighter, the growing plants have a fundamentally greater potential for water and nutrients available.
Against this background, the use of narrow graded seed is becoming increasingly important. A seed lot with only 10 mm variation in the grading size not only facilitates the optimal set-up of the potato planter, but also means that the planted material offers physiologically uniform starting conditions for the emergence of the potato plants and the subsequent quantitative and qualitative development of the crop. This system benefits potato planters with horizontal distribution belts as there tends to be smaller variations in the planting distances because of the more uniform size of the planted material, while the performance accuracy and capacity of planters with double-cup belts also improves. The narrow grading of the seed tubers is possible today on many seed potato farms by using efficient and gentle graders with more than three sizes.
The logistics of handling the seed potatoes and filling the potato planters is also increasingly gaining in influence as a factor that can affect crop performance. There are clear links between driving speed and quality of work, and it has also been shown that effective filling of the potato planter can significantly reduce non-productive time. Telescopic loaders are increasingly being used, which, because of the large clearance in front of their wheels, can service planters with trailing ridgers and shaping boards for the final ridge formation and supply seed tubers from big bags or large crates.
In addition, this technique can also be used to easily and evenly fill the fertilizer hopper, where fertilizer is placed in the rows beneath the tubers. Due to the tipping bunkers fitted to many potato planters, it is also possible to directly fill this bunker from a tail dumper. The position of the tipping bunker is also used to regulate the flow of tubers into the feed areas of the planting mechanism, and an automatic tipping control system controlled by level sensors can considerably relieve the effort required by the tractor driver. This also applies to GPS-controlled installation of the tramlines, or the automatic start or shutdown of all or individual planting elements at the beginning and end of the rows.
For economical reasons, the combination of potato planting and terminal ridge formation was introduced in Germany 20 years ago. In addition, the early build ridges can be left for much longer before requiring herbicidal treatment and a possible switching of the hills with a latter ridging that can result in increased undesired lateral outgrowth of the tubers is being avoided. From an agronomic standpoint, the system has special management requirements; only vigorous seed tubers will be able to grow without prejudice through a soil cover of more than 15 cm. In addition to optimal seed conditioning, therefore, warm but above all sufficiently dry soil is needed for the success of the crop. How this is achieved will be unique to every location.
Adjustment of the ridge-forming tools, either shaping boards or grid rollers, is important. On the one hand, the hills must remain stable, but on the other hand they have to retain a surface with in an open structure to support plant growth through effective water absorption and uninterrupted air exchange. The condition experienced by farmers this spring has once again shown how narrow the line is between success and failure in this respect.
The latest developments from manufacturers of potato planting technology, on machines from four to eight rows wide, can be seen during demonstrations taking place at PotatoEurope on Sept. 12 and 13, 2018, at Rittergut Bockerode farm in Springe-Mittelrode near Hanover. From 10 a.m. to 12 p.m. the manufacturers will explain how they set up their machines to master the conditions at the trade fair site, and from 2 p.m. to 4 p.m. the individual companies will demonstrate their planting technology.
The following companies have registered for the potato planting demonstrations:
- ALL IN ONE, Pförring (Germany)
- AVR, Roeselare (Belgium)
- DEWULF NV, Roeselare (Belgium)
- GRIMME, Damme (Germany)