Comfrey (Symphytum spp.) as a forage crop
Forbes, J.C.; McKelvie, A.D.; Saunders, P.J.C.
Herbage Abstracts 49(12): 523-539
The main interest in Symphytum spp. worldwide has been, and will probably continue to be, as a silage crop. It ensiles well (Watson and Nash, 1960; Mikhkiev, Rozenberg and Il'in, 1970; Raman, 1970; Krushkova and Odegova, 1971), although serious nutrient losses occur if the herbage is not sufficiently wilted before ensiling (Van der Zweerde, (1965). Even after wilting, comfrey silage may have such a high moisture content that dry matter intake by animals is seriously restricted. Growing comfrey together with grass to provide herbage with a higher dry matter content for ensiling appears not to be successful, because the comfrey is intolerant of competition from grass (Saunders, 1977; North of Scotland College of Agriculture, 1978). When viewed as whole, the scientific literature reviewed in this article tends to indicate that while comfrey possesses some attractive features as a forage plant, it is by no means a wonder crop. Its advantages a high content of protein and certain minerals are in most circumstances outweighed by difficulties involved in its husbandry. Little research has been done on husbandry techniques and systems for comfrey, but costs of establishment, weed con trol and eventual killing for replacement by other crops are high. Husbandry trials in Scotland (Holmes, 1946), England (McClean, 1964), Germany (Stalllin, 1964) and Canada (Lachance, 1968) have led these authors to conclude that there is little place for comfrey in conventional agricultural cropping systems. It is possible, however, that at some time in the future the potential of the crop may have to be reassessed if the current interest in S. asperum in the USSR is pursued to a successful conclusion.