28 



The Weekly Florists' Review. 



DEXDEMBBR 7. 1899. 



CHRYSANTHEMUM RUST. 



Through the courtesy of Prof. By- 

 ron D. Halsted, of the New Jersey 

 Agricultural Experiment Station, we 

 have received his circulars with de- 

 scription of and possible remedy for 

 the chrysanthemum rust. How widely 

 this circular has been distributed we 

 are not aware, but it is timely and val- 

 uable, and the kind of fruit that it is 

 pleasing to see our experiment sta- 

 tions produce. 



The exact species of fungus that pro- 

 duces the rust is not determined, nor 

 is it of great consequence to us how 

 long and crooked its name if we can 

 only fight it successfully. Prof. Hal- 

 sted says that it first came to his no- 

 tice in October, 1S97. We are sorry 

 to say that we have been troubled 

 with it at least six years. We fii-st 

 thought it was encouraged by a close 

 and rather dark house, and are not 

 sure yet but what that aggravated the 

 trouble. Still when Golden Wedding 

 was tried the following year in a par- 

 ticularly light house with abundance 

 of ventilation, the rust again appeared 

 and ruined the crop. 



We have noticed it on several varie- 

 ties, while on some, notably Ivory, in 

 the ?ame house we have never seen a 

 sign of it. We have seen it de.<;troy a 

 batch of Philadelphia, while by a clear- 

 ly defined line the variety next to it 

 was left unharmed. 



The bronzed appearance of the un- 

 der part of the leaf and its tendency 

 to crack instead of bend is a very sure 

 evidence of the rust. IJke the carna- 

 tion rust, which has largely disap- 

 peared even on Davbreak, a variety 

 that was during the epidemic the 

 worst infested, it appears to be al- 

 ready passing away, for this year on 

 the same place among twenty-five va- 

 rieties, we only noticed it on a few 

 Golden Wedding and the attack came 

 so late it did little harm. Prof. Cow- 

 ell, of our Botanic Garden, told me 

 three years ago that he was sure that 

 with the application of Bordeaux mix- 

 ture syringed on the foliage he had 

 arrested the rust and that subsequent 

 growth was healthy and clean, and 

 seeing the plants in flowering time I 

 can vouch for the above, as I saw the 

 finely develoned flowers. 



T.ast year T propagated Golden Wed- 

 ding from stock thit had a bad attack 

 of rust. When about a foot high In 

 three-inch pots the plants began to 

 show the rust. After being planted 

 out and thoroughly syringed with the 

 animoniacal mixtiire the remainder of 

 the growth was perfectly healthy, so 

 T am inclined to think that these rem- 

 edies are a sure preventive of this 

 troublesome fungus. .\nd when propa- 



gating the chrysanthemums it would 

 be well to dip the cuttings for a few 

 moments in the ammoniacal or Bor- 

 deaux liquid before and after putting 

 them in the sand. You never can get 

 at them so thoroughly with the syr- 

 inge and the labor and cost of giving 

 them a dip is nothing. The varieties 

 I have seen most troubled with the 

 rust are the glorious Golden Wedding, 

 Emily Henderson, Philadelphia, G. W. 

 Childs and several varieties that we 

 had to discard because they were no 

 good and rusty into the bargain. 



WM. SCOTT. 



(We print below the circular re- 

 ferred to by Mr. Scott. — Ed.) 



Outbreak of Chrysanthemum Rust. 



During the past month there have been manv 

 complaints concerning a destructive disease 

 among chrj'santhemums. It Is none of the 

 various blights, more or leas common to the 

 chrysanthemum, but one of the genuine rusts, 

 and closely related to those of the hollyhock, 

 carnation and asparagus, which have come to 

 us within the past few years with disastrous 

 results. 



General Appearance of the Chrysanthemum 

 Rust— Wben badly Infested with the rust, the 

 chrysanthemum plant becomes dwarfed, ths 

 leaves small, and brown on the under side. 

 Later on, instead of the green color of healthy 

 plants, there are the small, stiff, nearly leaf- 

 less stems, ending In stunted heads, that fail 

 to open Into marketable flowers. Over all the 

 lower portions of the plant is a brown powder, 

 as if they had been sprinkled with tobacco 

 dust. 



Close View of the Rust— Rusted chrysanthe- 

 mum plants, when closely examined, are 

 found to have on the under surface of the 

 leaves brown spots or blister-patches, slightly 

 raised, and covered with a dust that readily 

 rubs off. Such leaves are more or less Irregu- 

 larly discolored, so that the presence of the 

 rust may be detected by the coloration of the 

 l^'af. as seen from above. 



Nature of the Chrysanthemum Rust— The 

 rust In question Is due to a fungus, as before 

 stated, which Is probably Puccinia HleracII. 

 Mart. As yet. however, the form of spore 

 for a full determination has not been ob- 

 sen'ed upon the American plants. The fungus 

 consists of microscopic threads which grow 

 through the substance of the chrysanthemum 

 plant, feeding upon Its juices, and finally 

 Ijreaking out through leaf or stem, bear the 

 innumerable brown spores that give the dark 

 color to the affected parts. These spores are 

 borne by the winds, or driven by the water 

 from the hose, to other plants, where they 

 germinate quickly and spread the disease. 



Treatment — The chrysanthemum rust has 

 been known In this country for only a few 

 years. It having come first to the writer's 

 attention In October. 1897, and therefore ex- 

 perience with remedial measures Is here quite 

 limited. "We may, however, profit from the 

 treatment It has received In Europe. One 

 English grower, who doubtless Is writing out 

 of his sad experience, says: "Every gardener 

 should be careful where he obtains cuttings 

 and plants, otherwise he may quite unwit- 

 tingly introduce the rust Into his collection." 

 It Is of prime Importance that the stock used 

 for propagation be free from the disease and 

 all purchased plants likewise. Tn addition, 

 the plants In all stages of growth, from the 

 beginning, should be sprayed weekly with 

 Bordeaux mixture, or other equally effective 

 fungicide. The rust should be watched for 

 upon the older leaves, and when first met with 

 all foliage showing the least signs of rust 

 should be destroyed. If the disease Increases. 

 It may be best to burn the whole lot. fumigate 

 the premises, and start anew with fresh, 

 clean stock. 



This la an enemy that has proved Its ability 

 to strike a death blow, and It should be 



watched for, and, when found, destroyed. It 

 may be that some varieties of chrysanthe- 

 mums are not easily attacked, and these are 

 to be looked for and made use of accordingly. 

 There is no danger, as some have feared, 

 of this rust spreading to carnations or other 

 plants outside of the chrysanthemum group. 

 It does attack some of our wild plants, and 

 it is barely possible it came from them to the 

 chrvsanthemum. 



BTRON D. HALSTED, Botanist. 

 Experiment Station, New Brunswick, N. J., 

 November ». 1X99. 



HEIGHT OF CHRYSANTHEMUMS. 



What is the actual height of the 

 following mums planted out June 5, 

 single stem, one flower to a stem, 

 grown for cut flower trade, 8 inches 

 between rows and 10 inches apart in 

 the row: Ivory, Mayflower, Philadel- 

 phia, Bonnaffon, W. H. Chadwick, 

 Robinson, Maud Dean, Florence Pull- 

 man? H. C. H. 



In reply to above would say that 

 several things have to be considered. 

 Season is one. If the terminal bud is 

 taken it means a foot to eighteen 

 inches more than if the crown bud is 

 taken. As generally grown, unless 

 planted in very rich soil, they would 

 run about as follows: 



Ivory and Bonnaffon, 2 feet to 30 

 inches; Maud Dean and Philadelphia, 

 21^ to 3 feet; Pullman and Robinson, 

 3% to 4 feet; Mayflower, 4 feet; Chad- 

 wick, 4 feet on late bud. 



This would be in a modern house 

 with good light and ventilation. 



BRIAN BORU. 



CHRYSANTHEMUM SOCIETY OF 

 AMERICA. 



Work of the Committees. 



BOSTON.— Nathan Smith & Son, 

 Adrian, Mich., showed Stellata, which 

 scored 97 points by both scales. Also 

 white Bonnaft'on, which scored com- 

 mercial scale 87 points. 



ELMER D. SMITH, Sec'y. 



WOOD ASHES AND NITRATE OF 

 SODA. 



Kindly inform me the amount of 

 nitrate of soda you would consider 

 suflicient to cover a bed of carnations 

 6x100. If put on with wood ashas, 

 how much of the ashes should be used 

 with soda to cover above bench and 

 how often should soda be used as a 

 fertilizer? I have used soda with dif- 

 ferent results and I would like to get 

 reliable instructions. Our soil is a 

 good light sod soil, and carnations do 

 very well in it. F. D. R. 



My experience with nitrate of soda 

 in the mineral form on carnation 

 benches has been most disastrous. 

 Putting perhap;; 2 lbs. (not more) on 

 a piece of bench about 8x7 and thor- 

 oughly mixing it with the soil, which 

 was 5 inches deep, and then planting 

 the carnations, it killed most every 

 plant. This was an experiment, and 

 as the remainder of a long bed had 

 no soda and the plants lived and flour- 

 ished, we know it was nothing but 



