2l8 



TRANSACTIONS OF THE ILLINOIS 



notice in the above-mentioned locality on cultivated blackberries untii 

 the past few years; indeed, the first patch wholly killed, or made unpro- 

 ductive by it, of which we have any knowledge, was one owned by Air. 

 A. S. Barry, near Godfrey Station, five miles north of Alton, From 

 such facts as we are able to obtain of this patch, it is probable that at 

 first it appeared only on a few bushes, but afterwards spread so that at 

 the end of the second summer all the canes were either killed by it or 

 made unproductive. 



Of late we have met with this disease on cultivated blackberries in 

 several localities in the West. In all of which, judging from the rapidity 

 it is spreading, it is to be feared that whole sections of coimtry may yet 

 be swept by it. So contagious does it appear to be, that we believe that 

 not more than three summers will be likely to elapse, after it appears in 

 a plantation, before all the bushes in it will be made unfruitful. But 

 where the bushes mature the fungi, and it is allowed to remain to scatter 

 the seeds, it does not appear possible that a plant could escape its blight- 

 ing effects to the end of the second season. That the reader may form 

 his own opinion with respect to its contagious nature, we will give a 

 brief history of our own blackberry patch, together with experiments 

 and observations of this rust as we have found it elsewhere. 



To set our patch, we obtained roots enough from- the most vigorous 

 part of the Godfrey plantation, before mentioned, to set two acres. At 

 the time we took our roots, Mr, Barry, nor any one else, had supposed 

 that his bushes were diseased, only that the patch became unproductive 

 by peach trees growing up and producing an excess of shade, or had 

 exhausted the ground too much. Our roots were set on ground recently 

 reclaimed from the forest. On this new land the roots pushed up young 

 canes with great vigor. In the month of July, however, on perhaps a 

 hundred shoots last foimed, the young leaves had a crimped appearance, 

 with a perceptible tinge of }tllovv. This yellowish cast deepened daily 

 for from six to eight days, when the under sides of the leaves were cov- 

 ered with a deep colored orange-rust. So much would accumulate that 

 on the bush being jarred, or shaken, the rust would float oft' in the air,, 

 so as to be seen at a distance of several yards. Fearing that this floating 

 dust was the spores of the rust, and if left itvvould spread, we accordingly, 

 as soon as a bush became aficcted, dug it up. At the end of the first 

 season, this prompt treatment appeared to have exterminated it. In the 

 spring and early part of the second summer, only here and there a dis- 

 eased plant could be found. As in the first year, these were promptly 

 removed; but b)*. this time the roots of aflbcted plants had extended in 

 among those that were healthy, and the two had become so interwoven 

 that when a diseased plant was cut or dug up, from its distant roots dis- 

 eased plants would quickly appear. It also seemed to spread by the 

 mature rust being blown and lodging on the tender leaves of the 

 shoots; those just unfolding appearmg to be the only part on which 

 the rust vegetates. 



Our blackberry field is now four years old, and, after the second year, 

 diseased shoots have been constantly increasing, and in spite of all our 



