root-crop

It is a plant that expends a good deal of matter in maturing a considerable quantity of dense and bulky seeds, but as it propagates both by root and seed, it is probable that, as a root-crop, it would be highly advantageous to procure a variety that does not flower.

The Commercial Products of the Vegetable Kingdom Considered in Their Various Uses to Man and in Their Relation to the Arts and Manufactures; Forming a Practical Treatise & Handbook of Reference for the Colonist, Manufacturer, Merchant, and Consumer, on the Cultivation, Preparation for Shipment, and Commercial Value, &c. of the Various Substances Obtained From Trees and Plants, Entering into the Husbandry of Tropical and Sub-tropical Regions, &c. P. L. Simmonds

But it was not the inability of the soil to support so large a population that compelled so many to live in this miserable way, and exposed them to starvation on the failure of a single root-crop.

Little Journeys to the Homes of the Great - Volume 13 Little Journeys to the Homes of Great Lovers Elbert Hubbard 1885

Vegetable-oyster, or salsify, is another root-crop which may be treated precisely like the parsnip, and the seed sown at the same time.

The Home Acre Edward Payson Roe 1863

a turnip field, and the root-crop is being eaten down.

Modern Painting 1892