produce plants of apparently satisfactory appearance, which 

 nevertheless are very unsatisfactory on account of a high degree 

 of susceptibility to injurious attacks by parasitic organisms. 

 Plant pathologists agree that the problem thus suggested is of 

 very great fundamental importance and that definite' information 

 in this general connection should be made available as rapidly 

 as possible. It is seen that this problem involves both pathology 

 and physiology. Susceptibility to the attacks of a certain para- 

 sitic fungus or bacterial form may be considered as one of the 

 physiological characters that need to be understood for agricul- 

 tural plants, and it is especially important that the relations be- 

 tween such susceptibility and the salt treatment of the plants in 

 question should receive attention. 



It is consequently planned that cooperators in the present 

 project who are familiar with the experimental methods of plant 

 pathology may undertake experimentation in this field. Of 

 course such experimentation must needs deal with the plants 

 employed for the simply nutritional aspect of our problem; for 

 the beginning, with "Marquis" wheat and soy bean. 



It is planned that suitable groups of solutions may be em- 

 ployed in either water-culture or sand-culture and that when 

 the plants have reached a proper stage of development they may 

 be all tested for different degrees of susceptibility by being simi- 

 larly inoculated with the fungus or bacterium. The final records 

 in this sort of study will of course deal with the relative amounts 

 of infection and with the relative degrees of injury produced by 

 infection. 



In order that the results may be standardized, it is necessary 

 that the plants be grown according to the details of the foregoing 

 plan for work on salt nutrition itself, and it is practically neces- 

 sary that these inoculation experiments include uninoculated con- 

 trols having the same solution treatments as are given to the 

 inoculated cultures. The uninoculated cultures will then furnish 

 the regular plant measurement (of the foregoing plan), with 

 which similar data from the inoculated cultures are to be com- 

 pared. For an illustration, a duplicate water-culture series with 

 solutions of type I may be carried out until the end of the third 

 week of the seedling phase of wheat. At that time the visual 

 observations on the plants are to be made with special care, after 

 which one culture with each solution is to be inoculated and the 

 cultures are to be continued to the end of the five-week period of 

 this phase. Final observations and measurements are to be made 

 on all cultures. It is very essential that special attention be given 



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