12 WHEAT RESISTANCE TO TOXIC SALTS. 



diti'erciit conditions of climate and soil, and selections Avere made, 

 Avith the aid of Mr. M. A. Carleton, Cerealist of the Bureau of Plant 

 Indnstrv, with this end in view. All conditions under which Avheat 

 is grown are not, of course, represented. AVheat is raised in nearly 

 every portion of the temperate zone and under as diverse conditions 

 of soil and climate as could well l)e imagined. An attempt has 

 been made, however, to obtain varieties representative of the regions 

 presenting the greatest contrast in these respects. Cerealists have 

 discovered that wheats well adapted to a humid region will not thrive 

 in an arid or semiarid region, nor will varieties that are best adapted 

 to the latter conditions thrive in a humid environment. Varieties 

 representing each of these different climatic types were used in the 

 experiments. Unquestionably the soils of the various regions from 

 Avhich the seeds were obtained differed chemically to a great extent, 

 but in most cases data as to soil composition were not obtainable. 

 The influence of climatic and soil factors is complicated by the fact 

 that seeds are often transferred from one region to another. For 

 example, a certain variety might have been grown for a nimiber of 

 years in strongh' saline soil to Avhich it has become thoroughly 

 adapted, and then transferred to a semiarid region and a soil con- 

 taining less salt. AVere the seed procured from the iicav region 

 soon after the transfer, while the variety was not yet adapted 

 to the new conditions, probably it would still show the high degree 

 of resistance acquired under the former conditions. In some cases 

 it was possible to learn the exact history, for several generations^ of 

 the seed used, but in others it Avas impossible to obtain such definite 

 information. To meet the conditions of the experiments it was 

 thought advisable to select varieties from regions widely separated 

 geographically. Therefore, one variety from Africa, two from 

 Euroi)e, one from Asia, and six from America were obtained. Two 

 of the varieties are durum wheats and consequently of a different 

 species ; the rest are soft grained. 



The following descriptions of the individual varieties- will render 

 more intelligible the conditions under which they grew originall}': 



PRESTON. 



Tlie variety of wheat known as Preston (Tritieum indgarc) is a 

 hybrid, i:)roduced by Dr. AVilliam Saunders, of the agricultural ex- 

 periment station at Ottawa, Canada. In the spring of 18S8 Doctor 

 Saunders crossed the varieties Red Fife and Ladoga, obtaining a new 

 sort, which was called Preston. Red Fife was taken as the male and 

 Ladoga as the female jiarent. The progeny, he says, resembles some- 

 what both parents. The grain is very much like Red Fife. Both the 

 parent varieties are well established in that ^y^vi of Canada and were 



