64 AGRONOaiY [BoT. Absts., Vol. X, 



temperatures than do seeds of cultivated grains, the plant makes its appearance in the field 

 before those of the summer grains. Taking advantage of this fact, summer grain should not 

 be sown in an infested field until after the wild oats have appeared, after which shallow cultiva- 

 tion should be practiced to kill the young plants, care being taken not to cultivate so deep as 

 to bring new seed to depths permitting germination; the field should then be planted to the 

 grain desired. This method failing, the field should be mowed before the weed seed ripens 

 thereby preventmg infestation the following year. The seeds are capable of germination even 

 when several years old. To avoid bringing up old seeds to the proper depth for germination, 

 only shallow cultivation should be practiced in infested fields. — John W. Roberts. 



388. Camp, Wofford B. Cotton culture in the San Joaquin valley in California. U.S. 

 Dept. Agric. Dept. Circ. 164. 22 p., 11 fig. 1921. — A general treatise of the subject is pre- 

 sented together with a list of publications bearing on Egyptian cotton growing in the south- 

 western states. — L. R. Hesler. 



389. Damon, S. C. Experiences with alfalfa. Rhode Island Agric. Exp. Sta. Bull. 184. 

 S6 p. 1921. — A compilation of miscellaneous tests which have been conducted at the station 

 from time to time during the last quarter century is presented. — B. L. Hartwell. 



390. [Drucb, G. C.] [Rev. of: Goulding, E. Cotton and vegetable fibres, their produc- 

 tion and utilization. x + 2S0p. John Murray: London, 1916.] Bot. Soc. and Exchange Club 

 British Isles Rept. 5: 75-76. 1917 [1918]. 



391. Hansen, Albert A. Lawn pennywort: a new weed. U. S. Dept. Agric. Dept. Circ. 

 165. 6 p., 3 fig. 1921. — Hydrocofr/ie roiMndzyoKo, introduced from southern Asia previous to 

 1890 as an ornamental plant, has become rather widely distributed as a weed in lawns. It 

 is known to occur in the District of Columbia, Pennsylvania, and Kentucky. Directions for 

 its eradication are given. — L. R. Hesler. 



392. Hansen, Dan. The work of the Huntley reclamation project experiment farm in 

 1919. U. S. Dept. Agric. Dept. Circ. 147. 27 p., 4 fig. 1921.— A report is presented of ex- 

 perimental work with crops, including rotation, grasses, varieties, sugar beets, silage, and 

 fruits. — L. R. Hesler. 



393. Hartwell, Burt L. Field experiments which included the soy-bean. Rhode 

 Island Agric. Exp. Sta. Bull. 183. 15 p. 1920. — Numerous varieties have been tested. 

 Yellow-seed varieties have been sought which are late enough to give satisfactory tonnage for 

 silage, and yet early enough to yield viable seed or seed which might be used for human food. — 

 For use with corn for silage purposes, an insufficient proportion of the beans was obtained by 

 planting the crops together in the same drill. There were no indications that the corn derived 

 any advantage from the companionship. — Soy beans yielded more than cowpeas. The hay 

 contained from 2.75 to 3.00 per cent of nitrogen. — Although nitrate of soda did not decrease 

 the growth of soy beans, it did decrease the weight of the nodules. — The ability of soy beans 

 to secure their needs for phosphorus was found to rank between that of carrots, which ob- 

 tained their full requirements, and turnips which were practically unable to grow without 

 phosphatic application. — Soy beans were able to derive f of their potassium needs from a 

 soil so deficient that mangels could obtain only about J and summer squash about tV of 

 their requirements. — B. L. Hartwell. 



394. Hartwell, Burt L., and S. C. Damon. Fertilizer requirements of rotations in- 

 cluding com, potatoes, rye and hay. Rhode Island Agric. Exp. Sta. Bull. 185. 39p. 1921. — 

 Results for the 21st to 27th year of 5 different rotations together with results from associated 

 plants receiving differing fertilizers are presented; also, the record of the first 2 rounds of a 

 7-3'ear rotation. — From two 5-year rotations which differed only in that clover was included 

 in one and not in the other, the hay in one round of the clover rotation contained 132 pounds 

 more nitrogen per acre than in the other. The yields of the other crops did not differ much. — 

 Where no farm manure was used, fertilizer chemicals equivalent to different amounts of a 

 5:8:5 fertilizer sufficed in general for the different crops. — B. L. Hartwell. 



