Trap-plants for Eehcorms. 
175 
has only a quarter of the size of normally healthy roots of the same 
age. Blanched spots upon the root indicate the places where the 
eelworms are abundantly aggregated, and their presence is at once 
revealed by the use of the knife. The process of storing is powerless 
to arrest the progress of the disease, and in due time the material 
which is put into the clamp becomes a mass of putrid matter, whilst 
diseased sugar beets crushed in the sugar factory give only an indif- 
ferent yield of juice. 
For a long time this eelworm disease was attributed to exhaus- 
tion of the soil, or to a lack of potash at the disposal of the plant, 
and great efforts were made to combat it by deep and thorough 
cultivation, and by the use of chemical, and especially of alkaline, 
manures. Change of crop was tried, beet and mangel being kept 
off the land in certain districts for a number of years, but without 
avail, for it is proved that this eelworm can live equally well in the 
soil as in the plant. It is in these circumstances that resort has been 
made to the use of plantes-jneges, or “ trap-plants ” — in Germany 
they are graphically described as Fang-PJlanzen (capture-plants). 
The method recommended is to sow the selected trap-plants upon the 
infested land at intervals from April to August, and to pull them 
at least three times during the season, at periods four or five weeks 
apart. Tlie trap-plants are immediately burnt, the eelworms which 
infest them being thus destroyed. For the first sowing of trap- 
plants any of the varieties of cabbage may be used ; for the later 
sowings, summer turnips. These plants are capable of harbouring, 
in their dense growths of finely-branched rootlets, immense numbers 
of the eelworms. The seed is sown in rows 4 to 6 inches 
apart. It is only by carrying out the system rigorously and 
effectively that land can be cleared of eelworms by this method of 
trap-plants. A year or two ago the plan was put into operation at 
Halle by M. Leon Le Fort, with excellent results. 
An inquiry of practical importance suggests itself as to whether 
sheep, when fed upon eelworm-infested mangel, are capable of aiding 
in the dissemination of Heierodera Schachtii. In a recent article 
in the Comptes rendus, the question, Le mouton peut-il propager 
VHeterodera Schachtii ? is discussed at considerable length, and it is 
satisfactory to learn that the evidence is adverse to the supposition 
that sheep play any part in spreading the disease. 
The whole subject of eelworm-disease of mangel and beet is 
fraught with such interest that it has formed the material of an 
elaborate investigation undertaken by M. Joannes Chatin on behalf 
of the French Ministry of Agriculture, and now embodied in a com- 
prehensive report occupying fifty pages of the Bulletin,* and illus- 
rated by nine full-page plates. M. Cliatin concludes with certain 
practical recommendations which are worth recording. He says, 
in effect : “ Examine carefully the roots of mangel and beet, and, 
in such as show any signs of withering, look for the presence of eel- 
‘ L’Angulllulc de la Betterare {Ketercdera Schachtii), par M. Joannes 
Chatin. Bulletin No. 6, 1891. 
