a genus of herbaceous plants of the family Cru-ciferae. The sepals are erect, and the petals are yellow, white, pink, or violet. The fruit is a silique with a rostellum on top; upon ripening, the fruits of some species split into monosper-mous segments. There are eight species, distributed primarily in Europe but also in the non-European countries of the Mediterranean. Three or four species are found in the USSR, mainly along the coasts of the Black and Caspian seas. The wild radish (R. raphanistrum), an annual weed, is most often encountered among spring crops and on fallow lands (in the nonchernozem zone). The petals are yellow or, less commonly, white or violet. The wild radish is nectiferous. After its fruits ripen, the plant becomes harmful to farm animals. The seeds, which contain mustard oil, are poisonous to livestock.
The common radish (R. sativus) is widely cultivated, with varieties raised in vegetable gardens everywhere.
R. sativus var. sativus, a biennial vegetable plant, forms a root with a rosette of dissected leaves the first year and flower-bearing shoots and seeds the second year. The inflorescence is a raceme. The petals of the corolla are pink, violet, red, violet-red, or, less frequently, pale yellow. The fruit is an indehiscent silique. The variety is cross pollinated, primarily by bees. It is a cold-resistant hygrophyte. Its sprouts can tolerate a drop in temperature to -3°C, and its adult plants to -6°C. The optimum temperature for growth is 18°-20°C. The plant is grown throughout the USSR, but mainly in the central and northern regions. The roots contain, on the average, 1.58 percent sugar, 1.92 percent protein, and 1.55 percent cellulose; they also contain enzymes and 8.3–29 mg percent vitamin C. The roots may be eaten fresh.
The best radish varieties cultivated in the USSR are Graivo-ronskaia, Zimniaia Kruglaia Chernaia, Zimniaia Kruglaia Bel-aia, and Margelanskaia. The most suitable soils are fertile loams with a neutral pH. The seeds are sown in the spring (for use in the summer) and in the summer (for use in the autumn and winter). For winter storage the roots are gathered before autumn frosts. The average root yield is 200–300 quintals per hectare, and the average seed yield is 6–14 quintals per hectare.
V. A. ERSHOVA