Wasse Mechanisatie from Hijken (Dr) has become an importer for the Benelux on behalf of the Danish machine builder MRS Plant Technology, which produces machines for potato cultivation. The Opti Weeder and the Crown Crusher enable mechanical weed control and haulm killing without chemicals. And that coupled with a high capacity. The results from Denmark are promising.
Responding to the phasing out of chemical use
Wasse BV . has a network in Denmark due to the import of Samson and Fasterholt . This year Gerry Wasse and Wouter Truin came into contact with Michaël Stolberg-Rohr (MSR). This machine builder spent eleven years developing a mechanical alternative for weed control and haulm killing in potato cultivation.
In Denmark, a country that has similar cultivation and soil conditions as the Netherlands, it is only allowed to apply pre-emergence chemistry for weed control. Danish growers therefore go through the crop three times with the Opti Weeder before it closes. In addition to a well-functioning technology, a large capacity is therefore also important.
Mechanical growth stop without chemistry
In the haulm killing, according to Gerry Wasse, the use of the Crown Crusher offers the same advantage as Reglone at the time. Namely a large processing capacity and the death (growth stop) of the foliage immediately in one day. “The effect is based on tearing the root growth point of the potato stem. As a result, the plant immediately lets its sap flow out and thus ’empty blood’, as it were. After that, there is no more regrowth and the tubers start hardening off immediately, so that you can harvest 14 days later.”
For the Dutch market, Wasse sees great added value for potato growers for this application, who can either steer very well on size grading (seed potatoes) or benefit from maximum growing days (consumption/fries/starch).
The ‘Crown Crush element’ consists of two horizontally interlocking cutting discs that rotate and act as saw blades. The top disc spins 30% faster than the bottom one. “These rotors grab the haulm and zip it off. Because the pulling speed is higher than ground speed, the stems are stripped off and a frayed crack is created that splits right through the root growth point at the bottom of the stem. As a result, the plant dies immediately afterwards,” product specialist Wouter Truin explains how the ‘growth breaker’ works.
“The Crown Crusher has a working speed of 12-13 km/h. With a 4-row machine, this means a capacity of approximately 3.5 hectares per hour. And you’re done in one pass’. The cut foliage can optionally be left on the ridge or be turned into the ridge using the vertically mounted counter-rotating ‘whiskers’.
Although the machine runs ‘over the ridges’, the tuber damage is not too bad. “Because the elements make contact with the ridge, it occasionally happens that potatoes that grow at the top or outside the ridge are exposed. That is insurmountable. A test in Denmark measured 47 kg of damage or green on 16 cubic boxes. Which comes down to 3 per mille”, explains Truin.
The Crown Crush elements are powered by hydraulic motors. The oil consumption per element is 65 liters per minute. With four elements, the machine therefore requires 260 liters per minute, which is beyond the capacity of the oil pump of a modern tractor (approximately 110 liters/minute). That is why a PTO driven hydraulic unit is needed in the front linkage. “That requires an extra investment, but with the aggregate in the front linkage, the combination is well balanced. And the great advantage of haulm killing with this method is the high capacity (3 to 4 hectares per hour) and the high degree of controllability at the correct tuber size and the desired harvest time,” explains Truin.
The Opti Weeder and Crown Crusher use the same basic frame in which the elements are suspended in duo-sets both vertically and horizontally in a parallelogram construction. As a result, the elements follow the ground and track. Overlapping connection rows are therefore not a problem. The machine is available in a four-, six- or eight-row variant.
The machine hangs in the lift but the elements are supported on both sides on the flanks of the back. A support element is mounted in the middle of each duo set, which consists of a running disc and a support arm with running wheels stretched 1.5 meters forward. This support arm then runs forward in the back gutter on the outside next to the tractor wheels, or in the middle between the double air cultivation tires, thus ensuring forced steering of the duo weeding or crushing elements.
Growing year 2022 in the Netherlands
Wasse and Truin examined the operation of the machine in Denmark several times last season. The machine has now been operational for two seasons at dozens of larger potato growers (100 to 350 hectares) on various soil types (sand, clay, peat). The growers are positive and report that the effect for weed control and growth arrest is comparable to what they were used to with chemical applications. Setting up the machine does require good instruction.
Next year, Wasse BV will demonstrate the Opti Weeder and the Crown Crusher at a customer on a 15-hectare plot and they are in talks with an independent research institute to monitor and assess the operation of the machine. Two extra Crown Crushers will be in stock because Gerry Wasse sees the most opportunities in the Netherlands for this machine.