Rape, especially when young, looks like varieties of Swedish turnips. Its root, however, is not fleshy but is more like the root of a cabbage, penetrating the soil to a considerable depth. The leaves are numerous, large and spreading, bluish green, sweet, succulent and tender. The flowers are in a large open inflorescence, bright yellow and about half an inch wide when fully developed. They are fertilized by insects.
Wild Rape is indigenous to northern Europe, where it occurs especially along seashores. It is grown practically all over Europe, in northern Asia, the United States and eastern Canada.
Rape requires a good rich soil, well cultivated and with sufficient moisture. Best results are obtained on clay loams which contain large amounts of organic matter. On light sandy soil or stiff clay the returns are generally small. It likes a moist and not too hot climate but can be grown in comparatively dry and hot regions if the soil is rich and holds some moisture.
Rape is either annual or biennial. The annual varieties are grown principally for their seed and are called summer rape; Winter rape, such as Dwarf Essex, is biennial. Only the latter varieties are important as fodder plants for Canada.
Habits of growth:
The development of Dwarf Essex and Other fodder varieties is not dissimilar to that of turnips. The seed should be sown at about the same rate per acre two to four pounds - and at about the same time, either in drills or broadcast. The foliage is ready for pasture during the autumn. If protected against severe cold during the winter, the remaining stalks produce seed the following year.
Rape has a high feeding value for sheep, pigs, store and fattening cattle. As it is very succulent - that is, contains a large percentage of water-it is difficult to cure it into hay and when cured it is of comparatively little value as the leaves crumble to powder. It is principally used for pasture and to some extent as a soiling crop. It is not much used for ensilage.