P1«FACE 



This workshop in pnytonematoiO'^.y was neld at tne University of 

 Tennessf:e during the period ol July 1-b, 19S7 as another one of the 

 activities of tne Southern Kegionai Meniatoiosy Project (S-19). Tne 

 costs incurred by the discussion leaders, by the representatives from 

 the member states of the regional project, and for the publication 

 of these notes were Dome by a grant from the Rockefeller Foundation, 

 Acknowledgement ana tnanks are also extended to the U, S, Department 

 of Agriculture for permitting participation of certain pei-sonnei as 

 discussion leaders. 



Althougn some of the talks were prepared in a written form by 

 the speakers, to spare the discussion leaders the burden of preparing 

 formal papers, the talks and discussions were tape recorded at the 

 workshop. As time permitted, the recordings were transcribed and 

 Shaped into a more or less uniform pattern for print-ing, Tnese drafts 

 viere submitted to the speakers for any corrections atid c/,arifications 

 they wanted to make, Tnen the papers wei'e prepared into the final form 

 as presented here. The editor is responsible for the illustrations 

 which had to be redrawn to a suitable size from original copy or from 

 notes. He is also responsioie for some rewriting ana editing of portions 

 of tne taped material v/hicn could not be written verbatiim, for example, 

 discussions based on ullustrations or where there were difficulties 

 of clearly recording all that was said. Editorial intervention was held 

 to a minimum and it is believed tnat the objective of accurate reportage 

 of the workshop has been maintained. 



There was one regrettable casualty; the recording of Dr, Overgaard 

 Nielsen's talk and the extensive discussion tnat follovxed was accident- 

 ally erased. Dr. Nielsen kindly wrote out the highlignts of his presen- 

 tation but, as the participants at the workshop will recall, a great 

 deal of interesting material has been left out of this talk and dis- 

 cussion as it is printed here. 



The organization and pagination will be evident in the table of 

 contents. It is hoped tnat this arrangement will be as useful to the 

 reader as it was in preparing this material a piece at a time for the 

 printer. 



Eldon J. Cairns 

 Editor 



