1910] FIELD CROPS. 187 



Observations on the relative value of various forms of lime and phosphorus 

 in maintaining soil fertility are held to indicate that carbonate of lime is prac- 

 tically as efficient as the burned forms of lime for correcting soil acidity ; that 

 raw rock phosphate can be used to fair advantage when employed in rotations 

 where considerable amounts of organic matter are turned under; that lime 

 alone has not resulted in a better stand of clover; that phosphorus carriers 

 vary to a marked extent in their effect on the crop, their value decreasing in 

 the following order: Acid phosphate, basic slag, sodium phosphate, bone meal, 

 and raw rock phosphate; that with applications of raw rock phosphate wheat 

 yields have increased as the experiment progressed ; and that high magnesium 

 lime has given as good results as high calcium lime. 



Extensive variety tests with wheat have been described elsewhere (E. S. R., 

 41, p. 39), the results for the past year corresponding very closely with those 

 of the previous tests. A study of the performance of different varieties and 

 types of wheat grown under various fertilizer treatments, ranging from many 

 times the optimum requirements of the plant to the minimum quantity of 

 plant food required for a 25-bu. yield, is noted. The results indicate that the 

 amount of potash taken up during growth and the proportion of phosphorus, 

 potassium, and calcium vary somewhat with the different varieties. 



Johnson County White corn is deemed to be best for Delaware conditions, in 

 many cases producing more than 100 bu. per acre. Reid Yellow Dent and 

 Leaming appeared to be the best yellow sorts, although they yielded from 8 

 to 10 bu. per acre less than Johnson County White. Observations on seed of 

 hybrid origin, as compared with pure seed, indicated that the former out- 

 yielded the latter on both poor and fertile soil. Smooth ears of Johnson County 

 White also gave better results than rough ears on poor land, there being little 

 difference when the two were planted on fertile soil. A study of the effect of 

 variations in the physical characters and the chemical composition of the 

 kernel on the vigor and yield of the plant has not as yet revealed any wide 

 differences in yield from corn of different physical characters when grown 

 under good environmental conditions, although noticeable differences in the 

 degree of vigor of the plant were observed under slightly unfavorable circum- 

 stances. The study has also shown a wide range In the physical characters of 

 ears in the same variety. 



Silver Mine and Swedish Select Oats have given somewhat better results 

 than the other varieties of spring oats tested, although the crop in general is 

 regarded as unprofitable. Limited tests with winter oats are said to have 

 given promising results. 



The Wilson, Peking, and related strains of soy beans are deemed best for 

 general farm purposes, while Cloud is said to be one of the best varieties 

 for hay. 



[Report of field crops work in Hawaii, 1918], F. G. Keaijss, C. A. Sahb, and 

 R. A. GoFF (Hawaii Sta. Riit. 1918, pp. 33, 4S-51, 51-53, fig. i).— This describes 

 the continuation of work previously noted (E. S. R., 38, pp. 826, 827, 828). 



In a comparative test of the relative resistance to blight of three standard 

 varieties of potatoes and of the new Hamakua Hybrid made at the forage 

 crop station near Castner (Oahu), Early Rose and Burbank succumbed about 

 11 weeks after planting and Portuguese Purple and Hamakua Hybrid about 

 3 weeks later. 



Kukiruki and Okabu rice grown in rotation with taro at Waiau (Oahu) pro- 

 duced increases in yield favoring rotation which amounted to 872 and 944 lbs. 

 per acre, representing 17 and 17.7 per cent, respectively. 



Work with corn consisted chiefly of testing different varieties for resistance 

 to the leaf hopper (Pcregrinus nvaidis). Native Guam corn received from 



