A conveying arrangement conveys loose material in a conveying direction, in particular agricultural material. Several knives of a cutting assembly are mounted below a cutting area guiding surface. The material is first conveyed along the cutting area guiding surface and afterwards along a further guiding surface. Both guiding surfaces are mechanically supported by a connecting assembly. A positioning mechanism can pivot the connecting assembly upwards and downwards. This pivotal movement causes both guiding surfaces to be moved upwards and downwards. The cutting area guiding surface together with the cutting assembly can be shifted laterally, i.e. perpendicular to the conveying direction, and is guided during this lateral movement.

A conveying arrangement conveys loose material in a conveying direction, in particular agricultural material. Several knives of a cutting assembly are mounted below a cutting area guiding surface. The material is first conveyed along the cutting area guiding surface and afterwards along a further guiding surface. Both guiding surfaces are mechanically supported by a connecting assembly. A positioning mechanism can pivot the connecting assembly upwards and downwards. This pivotal movement causes both guiding surfaces to be moved upwards and downwards. The cutting area guiding surface together with the cutting assembly can be shifted laterally, i.e. perpendicular to the conveying direction, and is guided during this lateral movement.

A change of state of weed seeds to having reduced germination viability in under one minute by illuminating a seed with at least one of 2 J/cm.sup.2 cumulative illumination energy, and 0.2 W/cm.sup.2 irradiance, but no more than 7 W/cm.sup.2 average irradiance, of at least one of an Indigo Region Illumination Distribution (IRID), and infrared radiation that is substantially Medium Wavelength Infrared (MWIR) radiation, preferably 2-8 microns. The MWIR radiation from heated borosilicate glass or glass powder at just under 500 C offered a peak MWIR emission of 3.75 microns was unexpectedly effective, and can be used in a radiant and transmissive weed seed accumulator transport belt. The process can be incorporated into a harvester combine to convert a tailings flow prior to discharge on an agricultural field. An illuminated harvest combine using an illuminator according to the invention allows reduction of the weed seed bank.