Grain Guide 2018

50 Johan van Biljon, ARC-Agricultural Engineering Threshing drum losses Weigh the unthreshed seeds in the pan (in grams) – only the seeds and not the plant material – and use the following formula to determine the drum losses. Separation losses Weigh all the seeds remaining in the pan and use this mass (in grams) in the same way as for the threshing drum losses to determine the separation losses in kg/ha. Losses can also be converted to a percentage if the yield per hectare is known: Loss in kg/ha x 100 Yield in kg/ha 40 x mass of the unthreshed seeds (in grams) Width of header or table in metres EXAMPLE: Assume the mass of the seeds picked up as prescribed, minus the mass of the pre-harvest losses, is 15 g, and the width of the header or table is 3,5 m, then the header or table losses are: Remove the pan with all its contents and place it to one side. Now pick up all the seeds lying directly below the pan, as well as on either side, so that all the seeds over an area of 25 cm x the width of the harvester header or table have been picked up. Determine the mass of these kernels with the aid of the scale. Substitute this mass (in grams), minus the mass of the pre-harvest losses, into the following formula to determine the header or table losses. 40 x mass of the seeds picked up (in grams) Width of header or table in metres Header or table losses kg/ha = 40 x 15 3,5 = 171 kg/ha Threshing drum losses in kg/ha = Quickly calculate harvester losses 54 GRAIN GUIDE 2018 Implements