Benefits of Harvester front Extension in Reducing Canola Harvest Losses（Extracts）

Today in Iran，the cultivation of oilseed rape has been developed in all areas throughout the country.However，there are now some difficulties with land preparation，crop cultivation，and grain harvesting of this operation.Therefore，mechanized harvesting is completed using new technical operations；some arrangements were made with current common grain combine harvester companies and also several adjunct header extensions were added to the grain combine platform.The mechanized harvesting systems experienced considerable losses，especially with common combine platforms，as a consequence of lack of proficiency and also due to the need of specific machine components for canola harvesting. To study the effects of a modified platform and two platform extensions on canola grain loss，an experiment was conducted with respect to the quantity and the recognition causes of the losses. These models included the current cereal platform；Hamed，a platform extension which was made in Iran；and a Bizo platform extension using mechanical and hydraulic side knife cutter bars respectively.A statistically randomized complete block design was applied with six replications.Seed loss was measured with trays placed in the ripening crop prior to harvest.The results demonstrated that header extensions could decrease the amount of loss in a combine harvester with an increase in the distance between the platform auger and the cutter bar.Therefore，considering the total amount of loss，the significant differences were particularly found between the current cereal platforms and the other two extension platforms.Headers using side vertical cutting reduced losses to 71 kghm2 compared to 599 kghm2 where the common combine platform was applied.Furthermore，using hydraulic system instead of mechanical system and double knife cutter bar instead of the single cutter bar helps to decrease the amount of grain loss.39.60 kghm2 shattering seed loss was measured and from this rate it was 1.12% of total harvested yield.This rate was not a considerable amount of loss，and by improving the combine harvester conditions and adding a header extension at harvesting，the grain loss can be reduced.