WASHINGTON". 21*7 



tion being on the possibility of getting a high-nitrogen grain by 

 selecting high-nitrogen plants, the effect of germination on the 

 chemical and physical make-up of gluten, the influence of soluble 

 salts in flour on the gluten and the baking quality, and on the factors 

 determining size and shape of the loaf of bread. Analyses and mill- 

 ing tests of the wheat kernel during progressive stages of its de- 

 velopment were made and flour from partially developed heads and 

 also from germinated wheat was studied with reference to its bread- 

 making properties. The results thus far obtained showed that 

 gluten did not play as important a role in the baking quality of flour 

 as generally supposed, and this fact led to a careful study of the 

 effect on the baking quality of the flour of the constituents other than 

 gluten. A 5-year study of the chemical composition and milling 

 quality of Washington wheats was completed and a final report 

 issued as Bulletin 100. The selection of high and low nitrogen 

 plants of each of four varieties of wheat was continued for the fifth 

 year with negative results for this kind of selection work. 



The soil-moisture investigations were continued and a study was 

 made of the distribution of water through the soil under the condi- 

 tions of natural rainfall and under irrigation, the amount of soil 

 moisture lost by evaporation under different systems of tillage, the 

 amount of water required for the most successful growth of crops, 

 and the period of plant growth at which a sufficient water supply is 

 most critical, and the development of roots and stems of various 

 kinds of plants under limited, sufficient, and surplus supplies of soil 

 moisture. Work was in progress to determine the amount of water 

 required under field conditions to produce a pound of wheat, barley, 

 oats, rye, emmer, orchard grass, millet, corn, sorghum, soy beans, 

 field beans, potatoes, tomatoes, sugar beets, cabbage, carrots, and 

 onions. Pot experiments in the greenhouse were made to determine 

 whether plants are injured by lack of moisture before the wilting 

 point is reached, at what period in the life of the plant drought is 

 most serious, and the relation of the concentration of soil solution to 

 the amount of water required to produce a pound of dry matter. 



The department of botany studied tomato blight and isolated a 

 fungus apparently the cause of the disease. The fungus was gi'own 

 in pure cultures and cross inoculations on healthy plants were begun 

 to determine definitely the relation of this fungus to the malady. 

 The study of the toxic excreta of roots of conifer trees was still in 

 the preliminary stages of an investigation of the proper control of 

 culture solutions. In the study of the rots of the potato tuber four 

 distinct diseases have been recognized, and laboratory work to isolate 

 and identify the causative fimgi was instituted. Work was also 

 begun on the project on the progressive development of the wheat 

 kernel. 



