FIELD CROPS 443 



and soft sorts, early and late varieties, etc. The soft wheats are also 

 called starchy wheats and the hard wheats glutinous wheats. The 

 bread wheats include all varieties excepting those used in the prepa- 

 ration of macaroni, spaghetti, and other pastes. 



Varieties of wheat differ greatly in productiveness, hardiness, 

 drought resistance, resistance to lodging, quality of grain, and in 

 other characters. There are always best varieties for certain soils 

 and regions but no varieties that succeed best under all conditions. 

 It costs no more to grow a good variety than a poor one, and it is 

 therefore to the farmer's interest to secure the best sort for his locality. 

 All varieties grown in the vicinity should be observed and the best 

 one selected. Such a variety is more likely to give satisfactory results 

 than one brought from a distance because there will be little or 

 no change in its environment. 



Wheat varieties are improved mainly by selection and crossing. 

 Improvement by selection comprises the selection of seed and the 

 selection of individual plants. Varieties may be improved by selec- 

 tion or by crossing and selection together. Most varieties now grown 

 are the result of simple selection, and this kind of work is often 

 very profitable and replete with satisfaction. Dawson Goldep Chaff, 

 for instance, had its origin in a single stool of White Clawson 

 wheat which had been the only one to survive the winter in a bare 

 and exposed position. This variety has given excellent results in 

 New York, Michigan, and Canada, and is a standard sort in many 

 localities. This instance is one of the many showing the impor- 

 tance of selecting individual plants. 



The crossing of varieties is effected by means of artificial cross- 

 fertilization. The stamens must be removed from the blossom be- 

 fore the pollen sacks are mature enough to break and to pollinate 

 the pistil. After this is done the pistil must be protected from the 

 pollen of other flowers borne either in the same or in, other heads. 

 Usually all the flowers not desired for crossing are removed and the 

 entire head is then wrapped in tissue paper and the pollen of the 

 variety chosen as the male parent applied to the stigmas when 

 these are in proper condition. As soop as the application of pollen 

 is made the heads are carefully covered to keep other pollen from 

 entering and possibly fertilizing the blossom. The resulting seed 

 is planted and the crops for several years are subjected to rigid 

 selection to fix the variety. 



Soil. Light fertile clay and medium fertile loam soils of good 

 depth and well drained are best adapted to wheat culture. Heavy 

 clays are too compact and are inclined to bake, while highly fertile 

 loams tend to lodge the crop. Light clay soils have the proper 

 degree of compactness and are sufficiently retentive of moisture and! 

 better adapted to winter wheat and uniform seasons than the loams. 

 The clay soils are usually uplands, while the loam soils are either 

 lowlands or prairies. The alluvial soils of river bottoms, if not too 

 rich, usually make good wheat lands, because they are deep and 

 fertile and generally made up of clay, sand, and humus in propor- 

 tions, making them friable and porous and giving good drainage. 



