This cruciferous vegetable originated in Europe or Asia. When planted early in the spring it is an annual, but when grown in the fall the roots must be stored during the winter and replanted the following spring for the production of seed. It is one of the most important of the root crops, grown extensively as a fall crop and to some extent for early summer use.
Like other root crops, the finest specimens are grown in sandy soils, although the crop is produced in a wide range of soil types. To secure large yields and high quality it must be fertile and constant in supply of moisture until the roots have attained a marketable size.
The turnip thrives best in a cool, moist climate. As only 6 to 8 weeks are required from seed sowing till maturity, it may be grown successfully in the most northern cultivated sections. The leaves are hardy and the roots may be left unprotected in the open ground until there is danger of hard freezing weather.
White-fleshed varieties are in most common use although the yellow-fleshed sorts are preferred by some. In shape the roots are oblate, oval, spherical or conical. Formerly the flat varieties were generally grown, but the markets now prefer the more spherical forms. Some of the most popular varieties in cultivation are White Milan, Red or Purple Top (Strap Leaf), White Flat Dutch (Strap Leaf), Purple Top White Globe, White Egg and Yellow Globe.
For the early crop, sow the seed as soon as the ground can be prepared; for the late crop, sow in the latter part of July or early in August, depending upon locality. The rows may be 12 to 18 inches apart if a wheel hoe is to be used in cultivating, and 26 to 30 if a horse cultivator is to be employed. The tend-dency is to sow the seed too thickly, and thus necessitate a large amount of labor in thinning. If one good seed is dropped to every inch of furrow the stand should be satisfactory; even then thinning will be required. For the early crop the plants should be about 2 1/2 to 3 inches apart, while for the larger late varieties 4 or 5 inches between plants in the row will not be too much space. The seeds should be planted from to 3/4 inches deep. For the late crop the seed is often sown broadcast in well-prepared soil, and then raked in very lightly. This is a favorite plan on general farms, where roots are wanted for stock feeding and also for the home table.
When roots of uniform size and high quality are desired for market, it is much better to sow in drills, so that cultivating, weeding and thinning can be properly attended to.
See notes for beets (323).
See notes for beets (325).
Club root is the most serious disease. See notes on club root of cabbage (367). Maggots are also destructive sometimes. The application of carbolic acid emulsion is the most effective treatment (133). The emulsion is injected into the soil about the roots. This is rather tedious and expensive to practice on a large commercial scale. Turnips should always be grown in rotation with the noncrucifers to avoid losses from the attacks of insects and diseases.