Summary Statement 
OLAF S. AAMODT 
Agricultural Research Service, United States De- 
partment of Agriculture, Beltsville, Maryland 
The authors have adequately summarized the major points in 
their own papers. This summary by the Chairman will consist in 
brief statements in answer to the six basic questions used by the 
participants in the development of their subject. 
What screening procedures would lead to the selection of more 
productive plant and animal species for arid regions? 
1. Selection in natural environments of preadapted types. 
. Introduction and reselection in environments to be served. 
3. Basic research on biotic factors influencing plant response. 
4. Laboratory for basic studies under controlled environments 
of (a) salinity, (2) climate, (c) diseases and other pests, (d) nutri- 
tion, (e) heredity, (/) etc. 
5. International cooperation on a coordinated testing program. 
6. Regional technical conferences to screen ideas, as well as 
methods and procedures, and to promote new lines of reasearch. 
i) 
‘What are the genetic and physiological bases for drought re- 
sistance in plants and animals? 
1. Physiological. Basic research on water and irrigation re- 
quirements. 
2. Morphological. Characters that will not interfere with uti- 
lization. ; 
3. Habitats. (a) Escape of critical climatic periods. (4) Asso- 
ciation with other species. 
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