AMERICAN GRAPE GROWING 



by experts have failed to find a remedy. In its aspect, its 

 sudden and deadly effects and rapid spread, it resembles 

 the Eastern pear blight, and may originate in a sudden 

 stagnation of sap. Lately, however, it seems to have 

 spent its force, and very little is heard of its ravages. 



BLACK KNOT. This disease, which is also called 

 grape cancer, is caused by sudden stagnation of sap. 

 This may be the result of excessive pruning, late frosts, 

 or other causes which renders the vine powerless to elab- 

 orate all the flow of sap from the roots, which therefore 

 ruptures the sap vessels, stagnates and forms black ex- 

 crescences, frequently causing the death of the vine. 

 The remedies, or rather preventives, are longer pruning 

 and the use of longer cions in grafting. It would be 

 unreasonable to suppose that a vine which is vigorous 

 enough to produce a hundred feet of wood in a season 

 could be restricted to a dozen buds in pruning, or three 

 buds in grafting, and with them perform all the func- 

 tions which require as many hundred buds. When a 

 vine, otherwise vigorous, is badly affected by black knot 

 above ground, it is frequently saved by grafting it with 

 long cions below the diseased part. 



ANTHRACNOSE, OR SPANISH MEASLES. This does 

 not prevail here to any great extent. The leaves show 

 red spots, wilt and die off. An application or two of 

 Bordeaux mixture is said to check it. 



