Tech. D:2 



3. The Bar-rmann funnel technique is applicable to plant tissues in 

 the sai'ne maiiner as with t;oil samples. The plant parts are reduced 

 to small pieces and are submerged in water in the funnel. As 

 decay of the tissues may quickly develop and is detrimental to 

 the nematodes, small portions of the liquid should be drawn fre- 

 quently from the funnel and clean aerated watar added to them. 

 If a prolonged retention of the plant parts in the funnel is 

 necessary, it is better to transfer the tissues to another funnel 

 containing clean water every day or two. 



U. Seinhorst extraction technique . Seinhorst (1950) has devised an 

 extraction apparatus which overcomes the -ibove mentioned defect 

 of excessive bacterial cont£tmination and the resulting reduction 

 of oxygen in the water. Infested material is put in funnels in 

 the usual manner and sprayed with a mist of water from nozzles 

 located above. The excess water not entering the funnels is 

 caught on trays and floxiis away. The spray water slowly passing 

 around and through the tissues in the funnels gently flows out 

 the stem of the funnel into shallow trays below. The extracted 

 nematodes settle to the bottom of these collection trays and the 

 excess water passes through overflow outlets. The nematodes can 

 be collected and concentrated and are ready for use or examina- 

 tion. 



5. The incubation method proposed by Youjig ( 19514 ) was found to be 

 more efficient than the Eaennann funnel technique for recovery 

 of burrowing and meadovr nematodes from avocado roots. In this 

 method, washed roots are collected in a covered container, such 

 as a Mason jar, with a small amount of water, to maintain a 

 humid atmosphere, and are incubated at room temperature. 



Within a few hours, nematodes start accumulating with the small 

 amovint of wash vfater which drains from the roots to the bottom 

 of the container. These nonatodes are collected for examination 

 ii. Syracuse vratch-glasses. V/ater in the jar is maintained by 

 occasional additions from a wash bottle or pipette which, when 

 applied to the roots, washes down more nematodes. The roots can 

 be kept for periods up to several weeks, if care is taken to 

 keep the amount of standing water in the container small. If 

 cultures become overly contaminated, they may be flushed out 

 while Tn the jars with several changes of water. Nematodes can 

 be recovered from this wash water by use of the sleve-Baemiann 

 funnel combination process. 



Some suggested refinements of this technique include splitting 

 the roots lengthwise, stripping back the cortex of larger roots, 

 and the use of antil)iotics or other fungal and bacterial inhibi- 

 tors, which are known fo be harmless to stylet-bearing nematodes. 

 Examples of theFO include penicillin, calciijn propionate, and 

 the conimon sulfa dru'S. These materials may also have value for 

 retarding contaminant growth in water held in the Baemiann funnel. 



