1908.] 



Broom-Rape. 



179 



Sutt., which are the most important species agriculturally. 

 On germination, the seedlings are threadlike, somewhat 

 resembling those 01 dodder. The seedling of 0. minor, 

 becomes attached to the roots of the host by means of a sucker, 

 thereafter developing a thick fleshy stem which, says Percival,* 

 " grows upward through the soil, appearing above it like a 

 pale brownish- red asparagus shoot from 6 in. to 18 in. in 

 length." This stem gives rise to the spike of flowers. 



Prevention and Remedy. — 1. The chief means of preventing 

 infection on clean farms undoubtedly lies in using absolutely 

 clean seed, free from weed seeds. Although the seed of broom- 

 rape is easily removed from clover, yet on account of its 

 minute size it occasionally happens that samples are not entirely 

 free from the pest, and clover fields may become infested. 

 The second cut. of clover is sometimes almost, or quite, ruined. 



2. It has been recommended that wherever the plant is 

 seen it should be pulled up, and this may be done with ease, 

 as the broom-rape readily separates from the clover root. 

 When it occurs only in small patches it may be dug out and 

 burnt. If allowed to come to maturity the seeds will be 

 scattered broadcast in large quantities. Sorauerf says that 

 in case of widespread infection prevention of seeding is the 

 chief method of combating broom-rape, because spreading 

 by shoots or scions is slow and easily preventable by up- 

 rooting the plants. 



3. Clover should not be grown on infested land for a number 

 of years. 



4. Manures which will encourage the growth of the clover 

 and aid it in resisting the attack may be employed with 

 advantage. For example, ground lime and potash manures 

 judiciously applied may be of value in this way. 



5. Percival says, " When once established it is difficult 

 to eradicate before doing considerable injury to the crop, 

 and nothing short of ploughing up the clover will exterminate 

 the pest entirely." In this connection Frank saysf that badly 

 infested fields should in good time — that is after the first cut, 

 before the pest blooms — be deeply broken up, so that the clover 



* Op. cit. , p. 559. 

 t OP- cit-, p. 21. 



X Kampfbuch gegen die Sch'ddlinge unserer Feldfriichte, Dr. A. B. Frank, p. '251. 



M 2 



