FIELD CROPS. 449 



for the different sowings gave an average of 08.5 days, 779.5 hours of rec"orde<l sun- 

 shine, and (>,214.7 lieat units necessary to mature the crops. The heat units repre- 

 sent the mean temperature of the growing period muhiiiiied l)y the mind)er of days 

 of tlie growing period. In 1900 Fife, Bhie Stem, and Preston wheat required an 

 average of 10;> days, 908.4 hours of recorded sunshine, and 6,560.1 heat units to 

 mature. For the two years tlie average number of lieat units was (),.'}87.4, as com- 

 pared with 8,500 for all i)arts of Europe as given by Cooke. The jx-riod of growth 

 averaged approximately 100 days, as compared with 115 to 184 for Europe. The 

 author considers this difference to be due to other conditions of soil and cUmate, such 

 as soil temperature, radiation, evaporation, rainfall, moisture-holding capacity of the 

 soil, quantity of available plant foot, etc. Soil temperatures taken during the two 

 seasons at dejiths of 1 and 6 inches are shown in tables. In 1899, oats required 89 

 days and 5,525.9 heat units, and in 1900, 92 days and 5,847.3 heat units, to complete 

 maturity. Corn required 113 days and 7,423.3 heat units in 1899 and 114 days and 

 7,812.1 iieat units in 1900 to ripen. 



The wheat crop of 1900 grown under different methods of farming 

 {Xorth Dakota SUi. Bui. 48, pp. 735-74'-', fii/s- ^).— The results for 1900 of a series of 

 rotation and cultivation experiments with wheat, in progress for several years, are 

 reported. Three plats on which wheat had been grown continuously for 5 years 

 received different cultural treatment. The first was plowed 3 to 4 in. deep and given 

 ordinary cultivation; the second was plowed 6 to 7 in. deep, but otherwise treated 

 as the first; the third was given better cultivation and was spring plowed 6 to 7 in. 

 deep in 1900. The yields for the three plats were 4.7, 7.1, and 13.2 bu. j^er acre, 

 respectively. Plat 4 in this experiment had been treated like the foregoing plats 

 until 1899, when a crop of corn was grown. The grain on this plat stooled well, 

 stood 34 in. high, and yielded 25.4 bu. per acre. Plat 5, which produced potatoes in 

 1899 and which had annually grown a cultivated crop since 1890, yielded 24.3 bu. 

 per acre. Plat had been treated as plat 5, but was summer fallowed in 1899. This 

 plat yielded the longest straw and the most grain, the yield per acre being 29 bu. 

 Plat 7, which has grown corn, wheat, flax, and corn, in the order given, during the 4 

 preceding years, i)roduced 23.8 bu. of wheat in 1900. The yield on plat 8, which 

 had grown wheat annually since 1883, was but 4 bu. per acre. In previous experi- 

 ments harrowing after fall plowing, rolling and harrowing after spring sowing, and 

 harrowing again when the wheat was 6 in. high, increased the yield 4J bu. per acre 

 as compared with cultivation necessary to put in the crop. It is concluded from 

 these tests that good cultivation must be accompanied by a proper rotation of crops 

 for the profitable production of wheat. A test of growing flax on soils treated like 

 those above mentioned gave results similar to those of the test with wheat and led 

 to the sami' cfjiiclnsions. 



Variety tests of wheat, G. C W.\tson and E. H Hess [Pennsylvania Sta. Bui. 

 65, pp. S) — This Imlletin is a report on a test of 23 varieties of wheat largely grown 

 throughout the State. The work of testmg varieties of wheat has been in progress at 

 the station since 1890 (E. S. R., 11, p 731) Attacks of the Hessian fiy reduced the 

 stand to 55 per cent of perfection, and the average yield was only 13.40 bu. per acre. 

 The average yield of the 11 bearded varieties was 14.42 bu. and of the 12 smooth 

 varieties 12.47 bu. per acre. The yields of grain from the different varieties varied 

 greatly. The })ear(led varieties were injured less by the Hessian fiy and gave a larger 

 yield-of grain and straw and a heavier weight of grain j^er measured bushel than the 

 beardless or smooth varieties. The differences in yield of the smooth varieties are 

 considered due to the .lifferences in the damage done by the insect. Late-sown wheat 

 was injured less l)y the insect pest than early-.sown wheat and consequently gave 

 l)etter yields. In 1899 Reliable, a bearded variety, was sown on September 2 and 

 23, but the results in this case, owing to an early winter, were decidedly in favor of 

 the earlier sowing. It is conc;luded from these results that the seaaon governs the 



