Claas introduces Corio stubble cracker  

Claas presents the new Corio stubble cracker for effective and efficient control of corn borers when harvesting corn and faster decomposition of the corn stubbles. Thanks to the integrated mulcher, one subsequent operation is saved, which saves fuel and human resources.

Combating the European corn borer requires a high level of mechanical measures. After the corn harvest, further operations with a rotary cutter, knife roller or other tillage combinations are often necessary in order to effectively destroy the stubble and thus prevent the corn borer larvae from overwintering. With the Corio stubble cracker, Claas is now integrating a compact stubble cracker into a corn head for the first time, which saves an additional operation and reduces fuel consumption compared to conventional mulching.

Intelligently and compactly integrated

The stubble cracker works with one rotating plate per row, which is equipped with two massive, specially developed and coated mallets. These crush and splice any stubble below the first internode very effectively. Thanks to the coating, long operating times can be achieved with low set-up times and maintenance costs.

Two rotors are attached to the frame via a three-point linkage, so that excellent three-dimensional ground tracking is possible. The skid plate ensures a constant distance between the flails and the ground under all conditions, which reduces wear and ensures a consistently high quality of work. The rotors work at a speed of 1,200 rpm and are mechanically driven in pairs via a cardan shaft. A ratchet clutch effectively protects the gears from overload and contact with obstacles such as heavy stones. Thanks to the speed monitoring of the rotors, the driver receives an error message in the “Cebis” board computer if there is a risk of blockages. In addition, the rotor units are automatically lifted out by two hydraulic rams if there is a risk of overloading or if they come into contact with larger foreign objects.

The cracker units are also raised automatically when reversing and when raising the picker at the headland.

Low power requirement and minimal fuel consumption

Internal comparisons showed a required additional output of 3 kW per row, i.e. around 25 kW in the eight-row Corio 875 FC available from 2023 in a limited pre-series. When using the stubble cracker,  fuel consumption increases only slightly by around 2 l/ha. The Corio thus works more efficiently than the separate process with a subsequent mulching operation, especially since the pure locomotion energy of the carrier vehicle is excluded from the total calculation. Studies by the University of Applied Sciences Weihenstephan-Triesdorf confirm these measurements. As part of a student research project in 2021, they demonstrated fuel savings of 30 percent and a 50 percent reduction in labor compared to an additional process with a separate mulching operation. In addition, the use of the Corio reduces the risk of Fusarium infection, since the stubble rots faster and more effectively after the following tillage.

For road transport, the cracker units are raised hydraulically and are therefore more compact on the main frame, which means that visibility during road transport is only slightly restricted. With the eight-row Corio 875 FC, the stubble cracker increases the weight by around 400 kg.