14 BULLETIN 564-, U. S, DEPARTMENT OF AGRICULTURE. 



compact form with exceedingly short internodes and badly deformed 

 stalks and branches. In addition, these frequently shaken plants 

 were much darker in color than the others, plat 1 appearing almost 

 blackish, in fact. This color graded off as the shakings decreased 

 until it reached the checks, which were at that time a light-yellowish 

 green. 



At the time this plant injury was noted, examinations were made 

 in all other tests with the use of the bag-and-hoop being conducted 

 by the writers. These were large field plats, each some acres in 

 extent, but it was found that wherever the bags had been used the 

 plants presented this same deformed, dwarfed appearance, and the 

 more frequent the use of the bags the more pronounced the injury. 



The exact causes of this injurious effect of the shaking operations 

 on the cotton plant are not positively known, but it seems probable 

 that they are produced by several different factors. In the first 

 place, it was noted that a very large number of terminal buds were 

 foimd hi the bags at all shakings, and it is probable that this loss of 

 terminal buds was very effective in producing the bushy growth 

 noted. The loss of the terminal bud, of course, forced the formation 

 of adventitious buds and aided in developing the very irregular 

 branching. In addition to this, considerable injury to the stalk 

 itself was observed, due to the bending during the shaking operation. 

 In shaking the plants with the bag-and-hoop, it is customary to bend 

 the stalk near the ground at a rather sharp angle in order to insert 

 the plant into the bag before shaking it. This apparently resulted in 

 some crushing of the tissues at the point of bending. In extreme 

 cases noted hi the most frequently shaken plats the stalk was badly 

 scarified at the point of bending, and in some cases was actually 

 split for a distance of several inches. 



Still another effect was probably the disturbance of the root system. 

 Whenever the plants are shaken the movement pushes the soil away 

 from the stalk for a distance of from 1 to 2 or 3 inches below the 

 surface of the ground. This forms a small hole all around the stalk, 

 and it is probable that during the formation of this hole the important 

 lateral roots, which branch out near the surface of the ground, are 

 either very seriously injured or actually broken off. In fact, a num- 

 ber of plants examined showed a decidedly distorted development at 

 the surface of the ground. 



SQUARE COUNTS. 



Another effect of the shaking operation on the plants is shown by 

 the square counts which were made twice during the season. For 

 securing these records 50 plants were examined hi each plat and the 

 total and average number of squares per plant determined. The 

 first count was made June 13, while the second was made on August 

 11. The results secured are shown in Table 12. 



