[26] 



REPORT 



There are many theories with reference to the cause of cotton blight, some attributing 

 it to a fungoid gro^Yth, others to a peculiar poison in the soil, and still others to the 

 work of insects. This last-named theory carried it to the attention of the Commission, 

 and led me to make a careful study of the phenomenon. On taking up the plants, 

 even at the iirst indication of Avilting, I found all the rootlets completely dead and 

 usually rotted, and the main or tap root dead, with the bark ready to slip off and the 

 pith blackened. I found numbers of adjacent plants, showing no sign of blight above 

 ground, that were more or less affected in the roots. In a majority of these cases 

 many of the rootlets were already dead aud decaying, while the disease had not yet 

 reached the main root. In some instances half the main root was dead, while the 

 other half, with its attached rootlets, was living and performing its natural func- 

 tions. To some of these I carefully returned the soil without jiarticular disturbance, 

 not having unearthed the rootlets beyond an inch from the mam root, aud not having 

 unearthed the side of the main root more than three or four inches below the surface. 

 In no such cases did the plants recover ; they all died a few days later, and an imme- 

 diate examination revealed the fact that in the space of time named the rot had ex- 

 tended to the healthy side of the root and rootlets. I furt-her found that the first 

 attack was made on the very extremities of the rootlets farthest from the main root, 

 and usually on those deej) down in the ground. From these extremities it passed 

 gradually to the main root. When it had reached and surrounded "the latter the 

 leaves of the plant invariably wilted, as already mentioned. I saw not a single in- 

 stance of the recovery of a plant after the leaves had begun to wilt from the effect 

 of this blight. 



A most thorough study of cotton blight, made from time to time throughout the 

 season, has entirely convinced me that insects have nothing to do with it whatever. 

 This, of course, if I am correct (and I think I am), places it outside the scope of the 

 United States Entomological Commission. I found no insects associated with it in 

 any way that could be considered so much as even slightly suspicious. Nothing un- 

 usual was ever found upon the plant above ground, and the insects found in the large 

 quantities of earth that I examined, as taken from about the affected roots, were also 

 found in equal numbers about the roots of healthy plants in portions of the fields 

 where no blight had ever appeared. The microscope revealed to me a fungoid growth 

 upon the decaying roots aud rootlets, but I was not able to make sure that this was 

 otherwise than the result rather than the cause of the blight. I found the same fun- 

 gus upon other decaying vegetation, while I could detect no trace of it on cotton 

 roots in health, nor even in their earliest stages of blight. 



I trust 1 shall be excused if I here venture a step beyond what I consider the prov- 

 ince of the Commission to state that cotton blight, once started, appears in succeed- 

 ing years upon the same spots ; usually upon the highest and best drained lands of 

 the field. I was often told that any other croxD than cotton planted upon the same 

 spots would be likewise blighted, but this I subsequently found to be a mistake. 

 Rotation for a few years in other kinds of crops destroys it, so that when cotton comes 

 back to the same field blight is not apt to appear for a year or so at least ; and when 

 it does appear there is no certainty that it will appear in the old spots. This points 

 to the fact that it is something peculiar to cotton, and to the further fact that, be the 

 cause what it may, rotation of crops is the remedy. 



BOLL ROT. 



This is another phenomenon which has been greatly puzzling the cotton-planter 

 and his friends up to the present time, and giving rise, as such things usually do, to 

 any number of theories. It consists in the rotting of the interior of the boll after it 

 has attained nearly or quite to full size. In some cases the entire contents, both lint 

 and seed, become a fermented and putrid mass, bursting the boll and running out 

 frothing over the exterior, presenting a most disgusting spectacle. In other cases the 

 contents of but one or two divisions in the boll go into jjutrefaction, leaving the re- 

 mainder to mature and open out an inferior grade of cotton ; though this is the ex- 

 ception rather than the rule. Usually when the rot takes hold of a boll all its con- 

 tents are totally lost. 



The first indication of boll rot is a bruised orgreasy-lookiug circular spot about one- 

 fourth of an inch in diameter on the outer covering of the boll. As this spot grows in 

 age it changes gradually from its original dull green to a dark brown color, after 

 which, if the boll has not already burst, as a result of internal fermentation, it will, 

 if opened, be found to contain only the disagreeably-looking mass already described. 

 If found already burst, an examination will be apt to show its interior literally work- 

 ing with small worms, the larvae of insects that, attracted by the matter oozing from 

 its ruptured seams, have made use of it as a nidus in which to hatch and rear their 

 young. 



In times past tliese little worms, simply a result, and not at all connected with the 

 cause, have been charged with the authorship of this boll rot mischief, but I had the 



