The Arizona sentinel., 1889-07-06
SOUTHERN AGRICULTURAL.
Rust in Cotton.


 ject has generally been treated by two classes of writers from very different standpoints.
 1. The scientist, the college prOfes- sor, who understands a great deal about science, and who may be correct as far as his experience goes, but who has had few opportunities of observa- tion in the field.
 2. The practical farmer who has mo- ticed all the phenomena of rust, but who is unable to form conclusions from these observations.
 For years I have been observing rust in cotton, and the conclusion which l have reached, is that it is a general term for a variety of diseases, some times local in the leaf but generally in the plant itself, indirectly affecting the leaf, and is due to variety of causes. Injury to the leaf from parasites, de- fective circulation from general or special poverty, bad and irregular sea- sons, defective drainage, and some times from some poisonous element in the soil. l have seen rust or decay from all of these causes and he who asserts that rust is specific disease due to any one cause is, in my opinion, very much in error. We have it upon the authority of learned professor of the South Carolina University that rust comes from animal para sites, and he has established this to his own satisfaction by actually prop agating the disease. I am far from asserting that it never comes from this cause. have myself seen it from the depreciation of ordinary cotton lice, but that this can not be the general cause is evident from the fact that the insect enemies of plants always select the most healthy, because the most succulent growth. The cotton worm is invariably found first upon the most vigorous and tender plants. If this was the true cause, rust would prevail generally when the crop was under the most favorable conditions, and would exist without regard to seasons or soils. Such is not the fact.
 Again, that distinguished farmer and agricultural writer, Dr. Lee, for whom have the highest respect, tells us that rust is always the result of fungus growth. My observations do not sus- tain this. have never been able to detect any reddish deposit upon the diseased leaf as is the case with the grains, hence the name.
 Dr. Henry Ravenel, of Aiken, S. C., who was widely known as an eminent bootanist, especially in this class of plants, cryptogamia, once stated to me that he had been deeply interested in the subject of rust in cotton, having himself been for years cotton plant CT, and that he had never been able with the most powerful glass to discov- CT any fungus growth. Now, if Dr. Lee has detected this growth by the microscope, then there is here con- flict of high scientific authority. But has he or has he not accepted this theory from analogy with other plants.
 Again, David Dickson, the great practical farmer, asserts that rust is nothing but poverty; manure your land and you will remove the disease. There is no doubt that poverty of the soil is the most general cause of decay or rust; every observant farmer will admit of some limitation. Injudicious manuring of poor lands with very soluble fertilizer sometimes produces the disease This doubtless happens from the manure becoming exhausted or ceasing to act from want of moisture at the critical period when the plant, highly stimulated and loaded with fruit, is left in worse condition than if no manure had been used. Such has been the fate of many 8 promising crop. But this occasional experience Is no argument against the position that manure combined with humus is the best general remedy for rust, if not specific.
 Again, we hear great deal of late about kainit as sovereign cure. There is no doubt that upon certain lands where potash has been exhausted or is absent. that the effect of kainit is admirable in sustaining the plants 1 have seen remarkable illustrations of this on my own farm. But neither general or special manuring will pre- vent rust upon lands radically unsuit- ed tO cotton
 There are certain sour lands, gum ponds. which will not make cotton even with the best manures, and there are other lands which rust so badly as to indicate not simply the absence of fertility, but the presence of some noxious element, probably iron, in some injurious form.
 A summary of what I have written is that rust in cotton is rarely a disease of the leaf, but generally decay of the plant, and is due not to one, but number of unhealthy causes. But it may be asked why is it that cotton is more subject to this decay than any other of our cultivated crops?
 1 think we need not go far to find the rue explanation. It is said that wheat is the most civilized of all our agri- cultural plants, but 1 doubt if cotton may not be regarded as more civilized than even the great cereal, as it is fur ther removed from its natural or sav- age state. Compare the cotton plant