Ixxviii Department of Plant Physiology 



Slimmer session 

 Two courses were offered in the summer session. In Course A, 

 General Plant Physiology, there were lo students registered. In Course 

 B, Special Problems, 4 students were registered. In addition to the above 

 registrations 6 of the graduate students were present for the entire 

 summer, engaged in research work. 



INVE.STIGATION 



Mr. Hill has completed his studies on the respiration of fruits and 

 the eft'ect of certain gases, aeration, and other factors on the keeping 

 qualities. A paper will soon be available for publication. 



Doctor McCool has completed his investigations on the subject of the 

 toxicity and antagonistic action of the nutrient and other mineral bases 

 and the effect of manganese on plants. A paper is now available for 

 publication. 



Professor Duggar has continued and practically completed his studies 

 on the ripening of green tomatoes and especially on the factors influencing 

 the production of the red and yellow pigments. 



Professor Duggar and Mr. Prucha have continued their work on the 

 development of the sterilized-soil method for distributing the legume- 

 nodule-forming bacteria. During the past year, fourteen cooperative 

 experiments with farmers in different parts of the State were conducted 

 in order to test exactly the value of the soil cultures. Cooperative 

 experiments are also being made with the United States Department of 

 Agriculture. In addition, 500 cultures of the legume-nodule-producing 

 bacteria were sent out for test to farmers in various parts of the State. 

 The results obtained thus far have been very satisfactory. Evidence is 

 sufficient to prove that the method here devised for the distribution of the 

 legume bacteria is a successful one. A bulletin on this investigation will 

 soon be available. 



Mr. Prucha has been engaged during the past .year in investigating 

 various other problems connected with the subject of legume inoculations, 

 and has paid especial attention to an investigation of the factors influencing 

 the vitality of the nodule-producing bacteria. 



During the year the writer has completed his studies on the growth of 

 wood in the American larch and a paper will soon be in course of 

 j)ublication. An investigation on the regulatory production of enzymes 

 by certain fungi has been completed by him and a paper is now ready 

 for publication. A preliminary investigation on the growth of wood in 

 grape, apple, and peach has been completed, and a j^aper will soon be 

 available for publication. These studies are being continued in a more 

 intensive manner. 



