u. 



to be indigenous in VJestem Europe. It has a rather wide ho.3t-r,ange 

 amont wild and cultivated plants, England and Ireland were the last 

 countries in Western Europe where this eelworm became a problem. 

 This is clearly due to the insignificance of sugar beet growing there 

 before the second Woria War, In England it is legally forbidden now 

 to grow sugar beets on infested land, but there can be sone doubt 

 Whether this will do more than prevent some fields from becoming so 

 heavily infested that they will not be suitable for sugar beets for a 

 long period. In other European countries legal measures against the 

 beet cyst nematode would be of no use. Here the oniy possibility is 

 to grow beets in a suitable rotation. This point will be discussed 

 later. 



Heterodera major is a serious parasite of oats and barley in 

 Denmark, Swsden, certain parts of England, the Netherianas and Ger- 

 many, This damage shows a clear relation to the rotation followed, 

 but also other factors seem to be important, e.g. soil type. 



Heterodera goettingiana is rather widely spread on peas and 

 broad beans, and very persistent in infested fields. 



H, humili on hops, H. carotae on carrots and H. cruciferae on 

 cruciferous plants are of local mportance, whereas H. schachtii 

 subsp. trifolii may cause some damage in red clover. Its importance 

 in white clover in pastures in the Netherlands is doubtful. 



