FIELD CROPS. 931 



In combating the mistletoe, consideration must be given to the fact that there 

 nre bitWogical races of the parasite and attciition iiaifl to the trees liable to 

 infection by the particular form present. 



FIELD CROPS. 



Agricultural experiments. R. Ward. S. II. P.aylky. and W. K. Dunstan 

 (Rpt. Hot. danl. Olid OiuUriiccm. School I'unn lirU. (luiitna, l!)0ti-7, it/). J-I.i\. — 

 In fei'tilizer experiments with sugar cane it was found that the substitution of 

 nitrate of soda for suljiliate of anmionia on unlinied hind continuously manured 

 with sulphate of anunonia reduced the increased yield from 12.1 tons to 1()..'> 

 tons per acre, while the substitution of sulphate of ammonia for nitrate of soda 

 on the nitrate fields produced an increase from S.G tons to 9.2 tons. The 

 apparent ill effects of the long-continued use of nitrogenous fertilizers were far 

 more noticeable after nitrate of soda than after sulphate of ammonia. On the 

 lighter lands manured continuously for 30 to .50 years with sulphate of ammonia 

 the decreases in yield are considered as probably due to the action of this 

 substance. This injurious effect is remedied by the use of lime and not by 

 simply substituting nitrate of soda for the sulphate of anmionia. 



The results of these experiments have also led to the conclusion that if heavy 

 clay soil yields more than 0.008 per cent of phosphoric acid to 1 per cent citric 

 acid solution under conditions of continuous shaking for 5 houi'S, it is probable 

 that manuring with phosphates on that particular soil will not produce com- 

 mensurately increased yields of sugar cane. Work with different varieties has 

 shown that B. 208 is unsuitable for A'ery heavy clay soils, although in all the 

 tests on the exiteriment fields this variety has been characterized by a high 

 sugar content and a high purity. 



The results of fertilizer experiments with rice show that in 100 tests with and 

 without applications of phosphates 03 were in favor of the use of phosphates. 

 Basic superphosphate gave increased yields in 69 cases, superphosphate in 04, 

 and slag phosphate in 52. Assuming that the plats were of equal fertility in- 

 creases of 4.7, 7.3, and 9.6 per cent were due to the use of superphosphate, slag 

 phosphates, and basic superphosphate, respectively. 



A large number of varieties of cotton were tested and the results are briefly 

 described. Brief not€>s on the quality of each variety are given, and it is stated 

 that all the varieties of cotton submitted for examination can be most success- 

 fully cultivated in British Guiana. 



Work with field crops, F. II. Hall (New York State Sta. Rpt. 1907, pt. .?. 

 pp. 267-291). — A summary is here given of the work conducted with field crops 

 at the station dtn-ing the first 25 years of its existence. The crops entering into 

 this work were alfalfa, barley, corn, oats, onions, potatoes, sugar beets, tobacco, 

 wheat, and forage cro])s. 



Report on field trials on the manuring of seeds hay, .1. F. Blackshaw 

 (Midlinifl Affi: niid Dnirii Col. lint. I, 19U7-H, pp. II). — Fertilizer experiments 

 with rye grass and clover are reported. 



The results indicate that the use of commercial fertilizers in a favcu'able 

 season and on good ground may be profitable and that it is better to apply a 

 complete dressing than an incomi)lete one. Unit for unit, the nitrogen in 

 sulphate of anmionia and nitrate of soda was of equal value to the crop. 

 •Muriate of potash was the only form of potash giving a profitable return, and 

 then only when applied during the earlier part of March. The results indicate 

 that 1.30 lbs. of sulphate of ammonia and 210 lbs. of superphosi>hate applied 

 during the earlier jiart of Ai)ril, and 105 lbs. of muriate of jiotash applii'd during 

 the earlier p:irt of Mari-h is likely to give the most itrotitable yields of the 

 different fertilizer applications com|iared. 



