REPORT OF THE SOCIETY 25 



■subject. Possibly no phase of the subject has received as much attention, 

 after taxonomy, as the problems involving the life history of fungi, and yet 

 we do not know the life histories of many of our most common species. A 

 lack of this knowledge will no doubt explain our failure to control some of our 

 most common diseases. Closely associated with these pi"t)blemg of life history 

 are those involving the socalled "physiological species" or "strains", which 

 are the continual sources of so much confusion. The study of these pro- 

 l)lems will necessitate improved technique in the handling of cultures and 

 the making of inoculations, a knowledge of the factors controlling infections, 

 the resistance to disease and the growing of resistant strains or varieties. 

 These problems are united with bio -chemistry in one direction and with plant 

 l^reeding in another. This line of work appeals not only to those who have 

 that inborn love for the study of science but to those who are especially 

 interested in the increase o^f plant production. 



The diseases commonly referred to as yellows and mosaics have presented 

 puzzling problems for more that 100 years and our progress has been very slow. 

 We know very little about their causes, transmission or control. The recent 

 demonstrations that some of them are carried in the weeds of the field without 

 showing extern,al evidence of their presence is encouraging. The solution of 

 these problems necessitates technical training and skill of the very highest 

 degree. The study of environmental factors, such as character of soil, tempe- 

 rature, other plants and insects, presents many problems which are almost 

 untouched, but which will lead us into many fields of related sciences, such as 

 "biochemistry, soil-chemistry, ecology of plant life and entomology. This very 

 naturally leads to geographical distribution and involves the workers to a greater 

 or less extent in international problems. 



The discovery of Bordeiaux mixture in France in 1882 marks the first great 

 step in the control of plant diseases, but by far the grcjiatest progress in contol 

 measures since that time has bee,n made in the New World. We are now using 

 many sprays and dusts for orchard, field and garden; we are trekting seeds 

 and soils; using many othe^r methods which are' familiar to this audience. But 

 ■with all our progress, our treatments of plant diseases are far from perfect and 

 present many problems for both the rejsearch and field workers Too much of 

 our so called exf^e/rimental work is nothing more or less than "cut and try" work 

 without a scientific basis. Future research in treatment of diseases will involve 

 a more thorough knowledge of the life histories of the causal organisms, of the 

 host plant, and of chemistry; but will also bring the worker into close contact 

 with the horticulturalist, the agronomist, the entomologist and the producer. 



