66 HATCH EXPERIMENT STATION. [Jan. 



This year it has appeared in many places, both in this and 

 other States, occasioning considerable loss, as it is often very 

 destructive to infected plants. It is not yet generally 

 known, however, among those who cultivate the chrysanthe- 

 mum, though we fear that it may be by another year. Judg- 

 ing from the history of many similar diseases (asparagus 

 rust, carnation rust, hollyhock rust, etc.), it will not be 

 surprising if a general epidemic of this disease occurs next 

 year. It will be well worth while, therefore, for growers to 

 take precautions for guarding against it as much as possible, 

 especially those whose stock is already infected. Great care 

 should be exercised to get cuttings from vigorous plants, 

 unaffected by the rust ; and it will no doubt be profitable in 

 the end to spray them a few times during the summer with 

 the Bordeaux mixture or potassium sulphide, using one ounce 

 of the latter in two gallons of water, or stronger, if the 

 leaves will stand it. Should the rust appear on the young 

 plants, they should certainly be sprayed at once and at fre- 

 quent intervals thereafter, and the affected plants removed 

 and destroyed. It will be useless to try to save them as 

 they are doomed to destruction, or at best will only attain 

 a weak, sickly, worthless growth. When the plants are 

 placed in the benches for the fall, great care should be taken 

 that no rusty specimen goes in, else it may bring about the 

 ruin of the entire lot. Further than these suggestions little 

 more can be said about the disease until time shall have 

 shown what its seriousness may be and to what extent it can 

 be controlled. 



There are several other diseases affecting the leaves of the 

 chrysanthemum, so that some may be in doubt whether their 

 plants are really infested with the rust. It causes discolor- 

 ation of the leaves, like other less destructive diseases, but 

 may be distinguished from them by its production of small 

 pustules, of a dark-red, powdery substance, on the under 

 side of the leaves, something as in the carnation rust. This 

 red powder consists of the spores of the fungus, which re- 

 produce and disseminate it. 



