666 



WHEAT 



WHEAT 



(6) The durum wheat region, including parts of 

 the southern states of the plains. 



(7) The irrigated wheat district, scattered over 

 the Rocky mountain region. 



(8) The white wheat district, including the 

 larger part of the Pacific coast states. 



This classification recognizes certain qualifica- 

 tions, chief among which are color of grain and 

 percentage of gluten, which form the basis of the 

 arrangement. Since these qualifications are largely 

 affected by the particular section of the country 

 where the types are produced, it is a fair inference 

 to speak of such a classifica- 

 tion as a geographical one. 

 From such a study as the 

 |/] I / above it can readily be seen 

 that there is no single variety 

 or even type that can be sug- 

 gested as the best for the 

 whole country, and even if a 

 single variety were universally 

 adopted it would be but a few 

 years until it would be found 

 as varying in character as the 

 many sections where grown. 

 So marked is this that markets 

 have been created, and with 

 the opening up of new areas, 

 producing grain of unusual 

 character, the milling industry 

 has at times tindergone a com- 

 plete change. 



The production of varieties. 



The greater number of the 

 common varieties of wheat are 

 the result of chance rather 

 than of any scientific effort 

 for improvement. Wheat is a 

 self-pollinating plant, and be- 

 cause of this, rarely fails to 

 reproduce true to its charac- 

 teristics. As every grower 

 knows, however, there will 

 occasionally appear a new or 

 even unusual form in a field of 

 grain which may or may not 

 Fig. 901. resemble the variety among 



Polish wheat {T. Poioni- which it may be growing. Such 



mm) Two-th!rds f^^^g ^^^ ^^^^^^ ^^ " SpOrts," 

 natviral size. , ,, li. j. • j j. i 



and are the result of accidental 

 crosses between plants of the same or different 

 varieties. It is probable that these occur more fre- 

 quently than they are discovered and that close 

 observation would reveal many new and superior 

 varieties that are never isolated and reproduced as 

 distinct varieties. Without doubt the great major- 

 ity of our commonly known wheats have thus 

 originated, and it is only within a comparatively 

 recentttperiod that what are known as " pedigree " 

 or scientifically produced varieties have been 

 placed in the hands of growers. Every wheat- 

 growing region of the world has been explored for 

 the best varieties it was able to produce, and it is 

 safe to say that few promising varieties which can 



be found anywhere remain to be tested. Vast 

 improvement to the wheat crop has thus resulted, 

 particularly through the introduction many years 

 ago of what are known as Mediterranean varieties. 

 With the reaching of the limit of possible improve- 

 ment by this means, attention is being more 

 directed to the artificial production of new varie- 

 ties and the future improvement of wheat, for par- 

 ticular purposes as well as increased yield, will be 

 secured by these means. 



As has already been proved, the varieties intro- 

 duced from foreign lands have been found to be 

 most valuable for producing new varieties by 

 crossing. These wheats, coming as they do from 

 those regions near the original habitat of the 

 wheat plant, are found to have many of the very 

 features it is desirable to reproduce. 



A study of the needs of any region is always the 

 first requirement when new creations are to be pro- 

 duced. If the region needs a hardier variety or one 

 able to withstand some insect pest or disease ; if it 

 needs a stiffer straw, or a head less likely to shat- 

 ter, the proper combinations must be made to 

 secure these. 



The second natural step will be the study of 

 those varieties which may show the desired charac- 

 teristics. It is not always the case that a perfect 

 combination will result even when the parents with 

 which the crossing is effected present the desired 

 characteristics. The resultant cross may show a 

 weakening instead of a strengthening of some 

 desired quality. 



Rigid selection is the third step which must fol- 

 low hybridization. It is not a difficult thing arti- 

 ficially to produce new wheats, but the real task is 

 found in selecting those of value and growing them 

 true to the type secured. 



The good results secured by cross-fertilizing 

 wheats in order to produce new varieties are 

 numerous. Among these which almost always fol- 

 low, are two : increased vigor and greater produc- 

 tiveness. On the other hand, so great is the disturb- 

 ance caused by the crossing that difliculty often 

 follows the effort to select fixed types. 



Hybridizing wheats. — The first step in cross- 

 fertilizing wheat is to remove the anthers from 

 all the flowers on the spike to be fertilized. This 

 must be done while the anthers are yet green and 

 the pollen immature. If the head of wheat is com- 

 pact it is well to remove each alternate spikelet 

 and also the less perfect ones at the base and tip 

 of the spike. The work is done by using ordinary 

 botanist's tweezers. Care must be taken not to 

 break any of the anthers. It is best to protect the 

 emasculated head by wrapping it with tissue paper. 

 In a few days when the flowers on adjoining plants 

 are seen to be ready to open, pollen may be 

 brought from the chosen variety and deposited on 

 the stigmas of the emasculated head, and this again 

 protected as before. When ripe, the heads are 

 threshed out by hand and the matured grains 

 planted the following season. It often happens that 

 the head is so injured in the process that the grain 

 is shrunken or defective although still retaining 

 vrtaJJty- Often it will be found that the work has 



