Tractors equipped with carrot harvesters cannot collect onions. According to relevant public information, tractors with carrot harvesters are mainly used for harvesting carrots, carrots and other root vegetables, but not for harvesting onions. Although onion also belongs to root vegetables, it is different from carrots, carrots and other vegetables in size, shape and texture. Therefore, harvesting onions with carrot harvester may result in failure to harvest the whole onion, or damage and excessive waste of onions.