1917] FIELD CROPS. 337 



The germinatiou of the pollen on the stigma was accomplished 30 minutes 

 after the closing of the flowers. 



Notes are given on the color of the panicle and on the structure of the in- 

 florescence and of the flower. 



Field pea production, E. G. Schafeb and E. F. Gaines (Washington Sta. Bui. 

 UO (1917), pp. 3-16, pi. 1, figs. 2). — The production and utilization of field 

 peas are briefly discussed, and seven varieties described and comparative tests 

 reported. The Bangalia variety has produced the largest yields for a four-year 

 average, 31.8 bu. per acre. 



The value of immature potato tubers as seed, H. P. Hutchinson (Jour. Bd. 

 Agr. [London^. 23 (1916), No. 6, pp. 529-539). — This is a general di-scussion of 

 experimental work relating to the use of immature potato tubers for seed. 



It is concluded that immature seed is superior because (1) in using immature 

 tubers for seed the largest tubei-s of the most productive plants will naturally 

 be selected, thus resulting in increased yields, or, at least, in maintaining pre- 

 vious yields. (2) The cortex of immature tubers is thinner than that of mature 

 tubers, thus lessening the check on the imbibition of water from without, which 

 is necessary during the early stages of growth. (3) The amount and avail- 

 ability of the reserve plant food material may be greater in the immature 

 tubers than in the mature ones. (4) The length of time of storage may mate- 

 rially affect the amount and form of plant food material, which would favor 

 immature tubers due to the longer period of storage to which they are sub- 

 jected. The use of immature tubers for seed also promotes earliness, vigor, 

 and an ability to form tubers under adverse seasonal conditions. 



Directions are given for procuring and storing immature tubers. 



Fertilizing the potato crop, C. E. Thorne (Mo. Bui. Ohio Sta., 2 (1917), 

 No. 5, pp. 142-I46, fig. 1). — The results of fertilizer experiments at the station 

 with potatoes and wheat in a 3-year rotation of potatoes, wheat, and clover, 

 extending over a 23-year period, are summarized and discussed. 



An 1,100-lb. application for each 3-year period, carrying 50 lbs. of nitrogen, 30 

 lbs. of phosphorus, and 123 lbs. of potassium, half the nitrogen and two-thirds 

 each of the phosphorus and potassium being applied to the potatoes and the 

 remainder to the wheat, resulted in an average production of 190 bu. of potatoes 

 per acre for the first 12 years and 159 for the remaining 11 years, while the 

 wheat yields were 37.3 and 38.5 bu., respectively. When the total application 

 was made on the potatoes the average yields were 187 and 155 bu. for the 

 potatoes and 36 and 37 bu. for the wheat, respectively. 



Applications of 8 tons of yard manure to the potatoes, with no further treat- 

 ment for wheat, resulted in yields of 188 and 159 bu. per acre of potatoes and 

 30.3 and 33.8 bu. of wheat. Applying the manure to the wheat instead of the 

 potatoes resulted in potato yields of 175 and 129 bu. and wheat yields of 30.4 

 and 36.8 bu., respectively. Applications of 16 tons of yard manure all applied to 

 wheat resulted in yields of 192 and 175 bu. of potatoes and 34 and 37.5 bu. of 

 wheat. In total effectiveness the 16-ton manure application exceeded the 

 1,100 lbs. of fertilizer by from $3 to $4 per acre for the first period and by from 

 $4 to $7 for the second period. 



Land left continuously without fertilizer or manure yielded at the rate of 

 166 bu. of potatoes per acre for the first period and 103 bu. the second period, 

 the 63-bu. decrease being attributed largely to the growing of potatoes at too 

 frequent intervals on the same land. It is recommended, therefore, that pota- 

 toes be planted on a good clover sod on land on which potatoes have not been 

 grown for five or six years ; that from 12 to 16 tons of manure be plowed under 

 and supplemented with 300 lbs. of acid phosphate applied broadcast ; and that 

 5750°— 17— No. 4 4 



