240 EXPERIMENT STATION RECORD. [Vol.40 



Increases in yield ranging from 251 lbs. for American to 1.012 lbs. per hectare 

 for Montalban were obtained from flat cultivation over ridge cultivation. 

 Average increases in yield from the fertilized treatments over the untreated 

 checks for all varieties amounted to 1,026 lbs. per hectare for manure alone, 

 953 lbs. for ashes alone, and 575 lbs. for manure and ashes together. 



The oil content of plants grown on the check plat varied from 47.38 per cent 

 for American to 57.4 per cent for Kinorales. Manure alone resulted in an in- 

 creased oil content over the untreated checks of from 1.21 per cent for Big 

 Japan to 2.13 per cent for American, with reductions of 0.02 and 2.36 per cent 

 for Native Lemery and Kinorales, respectively. Ashes alone showed an in- 

 crease in every case ranging from 0.05 per cent for Kinorales to 4.91 per cent 

 for American, while manure and ashes together showed increases ranging 

 from for Kinorales to 6.3 per cent for American. 



The average percentage of shelled nuts obtained from the different varieties 

 amounted to 63.62 for San Mateo, 66.02 for American, 66.97 for Native Lemery, 

 68.46 for Montalban, 69.76 for Big Japan, and 74.32 for Kinorales. 



The composition of the potato plant at various stages of development, 

 J. T. Ramsay and W. C. Rohkbtsor (Jour. Dept. Apr. Victoria, 15 (1917), No. 2, 

 pp. 641-655, figs. 2). — The authors describe experimental work conducted dur- 

 ing 1916-17 in an effort to determine the rate of assimilation of plant food 

 from the soil by the potato and the relative proportions of the principal plant- 

 food elements contained in the plant at various stages of growth. A synthetic 

 soil was prepared containing L3 parts Band, 2 parts clay loam surface soil, and 

 1 part well-rotted farmyard manure, placed in wooden boxes 18 by 18 by 18 in., 

 and the boxes set in trenches to prevent too rapid evaporation. Before plant- 

 ing, each box was fertilized with 0.5 oz. each of acid phosphate and potassium 

 sulphate and 1 oz. each of ammonium sulphate and dried blood. When the 

 plants germinated a top-dressing of 0.75 oz. per box of nitrate of soda was 

 applied. Whole seed pieces were used and averaged 75 gin. per box. The 

 plants were harvested at four intervals of approximately one month each, the 

 total period of maturation for the fully developed plants being 124 days. De- 

 terminations were made of the green and dry weight of haulms, tubers, and 

 roots for each harvest, and chemical analyses were made of the different parts 

 for total nitrogen, phosphoric arid, potash, lime, and magnesia, and for soluble 

 nitrogen, phosphoric acid, and potash in the haulms at various stages of devel- 

 opment and compared with the above-ground portions of mature mustard, rye 

 and vetch, and alfalfa. 



The total dry matter produced per plant for each of the four harvests 

 amounted to 59.14, 320.32, 587.16, and 647.1 gm., respectively, and per acre, 

 2,083, 11,288, 20,692, and 22,804 lbs., respectively. 



The results of the analyses are tabulated and fully discussed. The conclu- 

 sions reached may be summarized as follows: Nitrogen, potash, and phosphoric 

 acid once absorbed by the potato plant were fully utilized, no migration from 

 the plant to the soil having been observed. The critical period of growth 

 occurred during the first six or eight weeks. The greater part of the phosphoric 

 acid entered the plant in the early stages of growth, concentrating in the haulm 

 and later migrating to the stolons for tuber formation, the very young tubers 

 being richer in phosphoric acid than the semi-mature or mature tubers. Potash 

 and nitrogen played a consistently even part throughout the growing period. 

 Practically the whole root and haulm development occurred during the tirst 

 two months. The amounts of lime and magnesia assimilated appeared to bear 

 a definite relation. Phosphoric acid and nitrogen present in the seed set were 

 largely utilized in sprout formation, while potash was apparently not directly 

 utilized. 



