29. 



5« Hoplolaimus unifonnis 



As this nematode occurred in all fields investigated 

 on sandy soils, a good amount of infomation could be collected 

 about Its reactions to different crops. The general ijnpres- 

 sion is tnat: 



A. The general level of infestation is highly dependent 

 on soil type. Tne nematode prefers iignt sandy soils. 

 It finds optimum conditions on other soil types than 

 P. pratensis and P. penetrans . 



B. There was hardly an influence of the crops on the 

 fluctuation of population numbers. In certain areas 

 repeated culture of a host crop did not Increase the 

 relatively low population. Occasionally high to very 

 high numbers were found among the roots of garden 

 shrubs, and also in some fields. In the latter cases 

 there were no apparent reasons (crop rotation or such) 

 for tne local build up. So we must conclude that 

 locally the soil offers suitable conditions for the 

 nematode • 



T 4. o^ experiments revealed an increase potential of about 

 1 to 200 in one year. Increases under field conditions seldom 

 exceeded 1 to 2, 



The species is very widely distributed and occurs over a 

 large range of soil types, but in some of these only rarely. 

 Nevertheless damage is very limited. 



