ANNUAL REPORT, 1935 11 



Different forms of nitrogen from each of these mixtures are now being 

 determined; namely, total nitrogen, ammonia, amino acid, amides, nitrate, 

 and humin nitrogen. 



The Absorption by Food Plants of Chemical Elements Important 

 in Human Nutrition. (W. S. Eisenmenger and E. B. Holland. ) It has been 

 found desirable to know to what degree the relative abundance of an element 

 in soils influences the intake of that element into the plant. Individual soil 

 plots were treated with basic copper sulfate, manganese dioxide, iron oxide, 

 and potassium iodide. 



Preliminary studies would seem to indicate that the rate of intake of elements 

 is not always proportionate to the amounts of the elements present. Evidence 

 from this experiment would lead us to believe that the reaction of ions from 

 salts does not function in the plant membrane as it does under conditions where 

 the mass action law is applicable. However, iodides do seem to be taken up 

 much more readily when the salts of this element are more abundant in the soil. 

 The intake of iron through a plant membrane is probably regulated to a con- 

 siderable degree by the hydrogen-ion concentration of the medium. 



Magnesium Requirements of Plants. (W. S. Eisenmenger and M. E. 

 Snell.) During 1934, the depressing effects of magnesium deficiency were 

 shown in a potato field on a farm about five miles from Amherst (Petrosky 

 farm). The college conducted experiments on this field in 1935, with oats, 

 potatoes, and corn. During the early period of the growing season when there 

 was abundant rainfall, the crops showed definitely the effects of low magnesium. 

 As the season progressed and the moisture supply became limited, the results 

 were less apparent. The yields were inconclusive. 



Onion Set Production. (M. E. Snell.) Owing to the early appearance of 

 the onion "blast" the past season, the sets stopped growing before many of 

 them reached the desired size for planting. This prevented getting much 

 additional information on the time of pulling the sets as a means of controlling 

 size. Very good stands were procured in every case from the four plantings 

 made at weekly intervals, and the early growth was excellent. The "blast" 

 appeared first and seemed to be most severe on the plots where rows were 

 eleven inches apart and on the two late plantings. The early plantings, where 

 the plants were older and tougher from having grown more slowly, and where 

 the rows were wider apart giving better circulation of air, were least affected . 



Onion Breeding. (M. E. Snell.) Unusually good results were obtained 

 the past season on this project. Seed production was better than in previous 

 years both with the inbred strains and with a number of selections which were 

 planted for massed crossing. Some of these were selections from previous 

 crosses and some from inbred strains only. The bulbs grown directly from 

 seed sown in the field were in most cases good, and those grown from trans- 

 plants and sets were again very satisfactory. A number of very good lots of 

 small sets for planting next year were also grown from inbred seed. A selection 

 of Sweet Spanish onions grown from seed on a nearby farm a year ago, was 

 planted for seed production. A fair amount of seed was procured from some 

 of the bulbs. 



Experimentation with Artificial Manure. (W. S. Eisenmenger and K. 

 Kucinski. ) During the past year, large quantities of different types of arti- 

 ficial manures were prepared in order to study their chemical composition and 

 fertilizing values. 



