CHAP. iv. MANGEL COMPARED WITH SWEDES AND TURNIPS. 969 



mended where the arable land is very heavy, as the constant tilling 

 and manuring make the soil more friable. Moreover, the crop is off 

 in time for the land to be ploughed up before winter, so that it may 

 receive the full advantage of frosts, and thus be made into a good tilth 

 for seeding. 



Although properly included amongst the " root-crops " of the farmer, 

 it is necessary to remember that mangel is a plant far removed in 

 affinity from the turnip and its allies. Turnips and swedes belong 

 not only to the same natural order, Cruciferse, but to the same genus, 

 and are, therefore, very closely allied to each other. But the mangel 

 belongs to the far-removed order Chenopodiaceee, familiar to us in 

 such a common weed as the white goosefoot, or such a well known 

 vegetable as spinach. The feeding-beet or mangel wurzel, and the 

 many varieties of sugar-beet, all belong to one species, Beta 

 vulgaris, of this order, and the beetroot as grown by gardeners in 

 this country is as much a garden mangel as the farmer's mangel is a 

 field beet. 



In the Rothamsted experiments on the continuous growth of mangel 





Fig. 449. Mangel or Beet Fly (Anthomyia betse). 



Female fly ; lines showing natural spread of wings. Pupa, natural size 

 and magnified. Eggs, magnified. 



upon the same land for eight consecutive years, commencing 1876, the 

 yield of roots of mangel, where nitrogenous manures were applied, was 

 much greater than that of either turnips or swedes, and there was also 

 much more leaf. Speaking generally, there was about twice as much 

 produce of roots per acre as of swedes with the same manures on the 

 same plots, and the quantity of leaf was more than twice as great. It 

 will not be forgotten that mangel seed is sown earlier, and the plant 

 has a longer period of growth; it has a much more deeply- penetrating 

 tap root, throws out a less proportion of its feeding roots near the 

 surface, and exposes a comparatively large area of leaf to the atmo- 

 sphere. With its more extended root-range it is less dependent on 

 continuity of rain when growth is once well established a fact well 

 exemplified in hot summers, and it thrives under a higher temperature 

 than the turnip. Hence the midland, eastern, and southern divisions 

 of the country are much more suitable for the crop than the north-west 



