MINERAL COMPOSITION" OP CROPS 57 



VARIETY 



Whether different varieties of the same species differ in mineral 

 content when grown in the same soil is still an unsolved problem. It 

 would seem reasonable that there should be differences, for the differ- 

 ences in yields among varieties indicate variations in the feeding power 

 of the plant that might be reflected in their mineral composition. 

 Considerable work has been done by Fort (lOx) on the mineral varia- 

 tions in different varieties of the juice of sugarcane, and his data indi- 

 cate that this factor may be of considerable importance. His studies 

 did not include careful soil surveys, but the same varieties of cane 

 occupied the same relative positions in regard to mineral content in 

 each area in which they were grown. Ayres (38) in 1936 found little 

 difference in the phosphorus content but significant variations in the 

 potassium content of two varieties of sugarcane grown on the same 

 soil. Similar results were obtained by Deomano (151) with four 

 varieties of sugarcane, and by Maxwell (401), who analyzed 13 varie- 

 ties of cane grown under uniform conditions. 



Remy (4-83), in 1922, failed to find any variation in the phosphorus 

 content of different varieties of corn grain, and Maume and Bouat 

 (399) reported, in 1937, similar findings on the sulfur content of differ- 

 ent varieties of wheat. Greaves and Anderson (220), on the other 

 hand, reported in 1936 that they obtained about one-third as much 

 copper in Kofod X Turkey variety of wheat as in Montana 36, and 

 many varieties of wheat varied significantly in copper when grown 

 in the same soil. Likewise, Bertrand and Levy (59) stated that while 

 aluminum is present hi all phanerogams, the amount present varies 

 significantly with the species, exceptional species containing as much 

 as 1 gm. per kilogram of dry matter. 



Peterson and coworkers (456, 459, 460) found that different 

 varieties of cabbage were remarkably uniform in their contents of 

 calcium, phosphorus, iron, and nitrogen, and similar results were 

 reported in 1938 by Vogel and von Hosslin (577). 



Delbet (145) examined potatoes grown in the same soil in Egypt 

 and found only normal variations in calcium, magnesium, potassium, 

 sodium, and phosphorus content of the several different varieties. 

 Poehlman (469), in some comprehensive experiments on two varieties 

 of soybeans, concluded in 1935 that 



Variance due to varieties is not significantly different from the variance due to 

 experimental error. This signifies that we cannot measure any significant differ- 

 ences between Morse and Virginia varieties of soybeans by chemical analyses of 

 the expressed plant juice for nitrogen, phosphorus or potassium. 



Weathers (580) apparently obtained no differences due to variety 

 in the calcium, magnesium, potassium, iron, manganese, or phosphorus 

 content of four varieties of lespedeza, all varieties having been grown 

 in three different localities. 



Some differences in potassium and phosphorus contents of corn 

 stover due to varietal differences were reported by Wimer (££#). 

 These variations were not always consistent under different condi- 

 tions, however, but they seemed to be affected greatly in some cases 

 by grain and stover yields. 



Ashton (18) reported in 1938 that different varieties of oats showed 

 only very slight differences in chemical composition. Van Itallie 

 (293) working with soils in the Netherlands, in 1937, found that 



