The article explains a change in the number of formed root tubers of mash with different norms and sowing dates. It shows that if sowing mash after winter wheat are planted in the early term (June 20-30) with a rate of 14 kg per hectare on the roots of one plant, then considering the number of tubers are 24, the increment was observed by 5 pieces comparing with the late (July 10-20) sowing one.