COTTON 



153 



good or well-fertilized soil and nearly level, well-drained 

 fields. 



The fertilizer for cot- 







ton is usually a com- 

 plete fertilizer (Fig. 

 96). Generally it should 

 contain two to three 

 times as much phos- 

 phoric acid as nitrogen 

 or potash. On soils 

 where cotton rust is 

 usual the proportion 

 Of potash may be in- FIG. 102. THE PETERKIN TYPE OF COTTON 



creased. If the plants make a very small growth on any 

 soil, the proportion of nitrogen should be increased. 



EXERCISE. Write in your notebook the names of the varieties of 

 cotton grown in the neighborhood. Which of these have large bolls? 

 Small bolls? Long staple? Very green seed? Partly sleek or very 

 dark seed? Small seed? Examine ten plants or even ten dead cotton 

 stalks and notice how widely they differ. Would there be any advan- 

 tage in selecting seed from uniform plants? Decide which kind of plant 

 you would select from. Why ? When the next cotton crop is mature, be- 

 gin to select and improve cotton by the method described in this section. 



NOTE TO THE TEACHER. If possible, make one or more excursions 

 into the cotton fields. Bend every effort to make the pupil see more in 

 a cotton plant than ever before ; for example, variations in leaves and 

 bolls on the same plant, ribs of leaves, the relation between earliness 

 and form of plant, etc. If this lesson is studied after the stalks have 

 been plowed under, let the practice be largely a study of the seed, 

 sizes, colors, fuzz, shape, hull and kernel, germination, etc. Dampen 

 seeds slightly with extremely thin flour paste, stir, then dry. Do the 

 seeds stick together? What is the practical advantage of this treat- 

 ment in planting? Advise pupils to try it at home on a bushel of seed, 

 using one cup of flour in two quarts of water. 



