Predac .fungi 18 



I9U9 I worked with Pratylenchus affecting boxwoods. At that time we 

 used to p\it chopped roots in the Baermann funnel and leave them for 

 about two weeks. Several times we recovered Arthrobotrys growing on 

 the water at the surface. 



Q. You mentioned that you had never observed nematodes feeding on 



fungi. I wonder if a turnabout thing can happen. That is, what 

 would happen if you built up large colonies of Aphelenchoides or 

 Aphelenchus , which can subsist on fungi, and introduced trapping fungi 

 into the situation, li/hich would win out? 



A. I think I would take the fungi. I do admit to not knowing whether 

 or not I have dealt with such nematodes in my cultures. As I have 

 before, I am not qualified to identify the eelworms. No doubt, I 

 mixed kinds of nematodes in the cultures, but they always end up 

 ■ ood for the fungi. 



Q. Have you tried to correlate the numbers of eelworm catching fungi 



with the number of nematodes in the soil? Do they have a very 

 definite effect on any part-icular nematode or on a very high population 

 of a certain nematode? 



A. I have a strong suspicion that if the nematode population is high, 

 there would be an increase in the fiingi. This is a topic I would 

 like to talk more about. In answer to the question, I would like to go 

 on to work with which I think you are familiar. 



Linford worked in Hawaii on pineapples in which he fii-st tried to con- 

 trol root-knot nematodes by inoculating the soil directly with pre- 

 dacious fungi. He found practically no beneficial results. He then 

 tried turning into the soil quantities of chopped pineapple tops. He 

 found that he had much better control of the root-knot eelworm. Linford 

 noted that although the root-knot eelworms were reduced, there had also 

 been a very large increase in the saprophytic nematode population. This 

 increase was followed by a great increase in the activity of the pre- 

 dacious fungi which were already present. This was in turn followed by 

 a drastic decren ;" in the populations of both the saprophytic and root- 

 knot eelworms. 



I have confirmed this kind of result in experiments on oats. We used 

 chopped cabbage leaves with manure in applications for control of the 

 cereal-root eelworm. We found a very high degree of protection against 

 the eelworm. This was judged on the basis of actual nematode counts 

 in the roots of seedlings. The protection obtained was very significant. 

 At the same time, the soil samples showed that the naturally occurring 

 predacious fungi were much more abundant. 



In all the experiments involving soil inoculations with predacious 

 fungi, I have found that when there were signigicant results, there 

 was some form of organic matter added along with the fungus. Those 

 experiments in which soil wa.s inoculated with only cultures of the 



