AOODST 4, 1921 



The Rorists' Review 



27 



GERANIUM LEAF-SPOT. 



How the Disease Spreads. 



The presence of red spicier, white 

 fly, pallid mite or other pests has little 

 or nothing to do with the spread of 

 leaf-spot on geraniums, but the method 

 of watering has much to do with it; 

 the watering, in fact, frequently is the 

 chief agency in carrying the disease 

 germs from one plant to another. Such, 

 in substance, is the conclusion reached 

 at the Maryland Agricultural Experi- 

 ment Station, after an elaborate series 

 of experiments. The tests proved that 

 the leaf-spot fuiigus, scientifically 

 called Cercospora brunkii, does not en- 

 ter the punctures made in the leaves 

 by pests, that direct transfer of the 

 insects from infected to uninfected 

 plants fails to produce the disease, and 

 that the rate of spread of the disease is 

 not materially increased by the pres- 

 ence of the insects, even if they are so 

 numerous as to disfigure the leaves with 

 punctures and the resultant stigmonose. 



On the other hand, it was clearly dem- 

 onstrated that in watering with a hose, 

 if the stream of water is driven through 

 the leaves in a direction parallel with 

 the surface of the bed, the leaf-spot 

 germs are quickly and surely conveyed 

 from the diseased to the sound plants. 



How to Identify Leai-spot. 



Since the leaf-punctures made by in- 

 sects, with the consequent stigmonose, 

 have a greater or less resemblance to 

 leaf-spot, it is important to be able to 

 distinguish between these different 

 blemishes of the foliage. The leaf- 

 spots, says a bulletin recently issued 

 by the Maryland Experiment Station, 

 "vary from about a millimeter in di- 

 ameter [a little less than one-twenty- 

 fifth of an inch] to several millimeters. 

 Infected areas examined by transmitted 

 light are characterized in the c.nrly 

 stages by the appearance of small, dark, 

 •opaque spots, which are later surround- 

 ed by a raised, transparent border. 

 The elevated rim is particularly notice- 

 able in dead leaves. Still later the 

 spots may become united and occupy 

 a considerable area of the leaf. Tliey 

 are usually light brown in color, tliough 

 sometimes almost black. But diseased 

 or dead areas that sometimes follow red 

 spider punctures are more or less angu- 

 lar and without the raised border." 



The injury caused by red spider and 

 white fly, says the bulletin again, "is 

 manifested by the appearance of small 

 watery pimples upon the k-aves. " 

 Kruptions on the leaves, with a super- 

 ficial likeness to the results of insect 

 punctures, can also be caused by ex- 

 posure of the plants to strong ammonia 

 tumes. But neither these eruptions 

 nor the insect punctures are similar in 

 detail to leaf-spot. The real leaf-spot 

 «an be identified bv both form and 

 <'olor. 



As already stilted, the leaf-spot dis- 

 ease, sometimes called circular spot, is 

 directly due to the fungus known as 

 Cercospora brunkii, but the activities 

 of this fungus are greatly stimulated 

 by certain greenhouse conditions. 

 "Spotted geraniums," says the bulle- 

 tin already quoted, "are most numer- 

 ous in commercial houses in spring 

 about the time that firing is discontin- 

 ued, and in fall just before firing is 

 begun. Atmospheric conditions within 

 the houses at these times frequently 

 combine a high relative humidity with 

 a low temperature. At such times the 

 spots become numerous enough to at- 

 tract attention and may injure the sale 

 of plants because of the unsightly ap- 

 pearance. Stock beds harbor the dis- 

 ease almost continuously, but a marked 

 increase in the number of affected 

 plants usually occurs at the above 

 stated periods. In this climate, at 

 least, lack of ventilation is one of the 

 chief factors responsible for the spot, 

 a fact judged from the difficulty in 

 propagating the disease in small houses 

 and from its relative scarcity in houses 

 where good ventilation is provided." 



Methods of Control. 



A most important part of the means 

 of controlling loaf-spot — the part that 

 consists largely in the maintenance of 



sanitary conditions — has been indicated 

 in the preceding paragraphs. The 

 necessity of good ventilation, with the 

 avoidance of unwholesome dampness, 

 has been shown.. The danger of spread- 

 ing the disease by careless watering of 

 the leaves, instead of watering from 

 below, has also been stated. 



In addition to these general precau- 

 tionary measures, the use of a good 

 fungicide is also likely to be neces- 

 sary. The fungicide especially favored 

 by the experimenters at the Maryland 

 Experiment Station is the Bordeaux 

 mixture, applied in the ordinary liquid 

 form. "The treatment with Bordeaux 

 dust," they say, "is promising, but 

 -cannot be as liighly recommended as 

 liquid Bordeaux. " In mixing the Bor- 

 deaux for all the tests, the 4-4-50 

 formula was followed — that is, four 

 pounds of copper sulphate and four 

 pounds of lime to fifty gallons of water 

 — and no injury to stems or leaves was 

 observed. 



Dipping the Cuttings. 



In the experiments the Bordeaux was 

 used, with excellent results, on a batch 

 of cuttings as well as on the plants. 

 "The cuttings," it is said, "were 

 dipped in Bordeaux and planted out 

 after the preparation had dried on the 

 leaves and stems." 



One of the advantages in thus dip- 

 ping the cuttings is the elimination of 

 the trouble that sometimes ensues from 

 discoloration of the foliage by the 

 fungicide, since "cuttings so treated 

 grow out of the marks of the applica- 

 tion by the time they are ready to be 

 shipped or set out." The assurance is 

 also given that "cuttings dipped in 

 Bordeaux, though they did not root 

 quite so freely as undipped cuttings, 

 usually developed into more vigorous 

 plants after removal from the cutting 

 bench." 



Harrisburg, Pa. — Mrs. Bertha I. 

 Keini, owner of the Longenecker Flow- 

 er Shop, at 804 North Third street, has 

 made announcement that the business 

 was removed to 814 North Third street 

 August 1. She also announces that the 

 shop will be known as the Keim Flower 

 Shop. 



Grand Bapids, Mich. — With a view to 

 enlarging and perpetuating the busi- 

 ness, Henry Smith recently conveyed 

 his establishment to a corporation, 

 known as the Henry Smith Floral Co., 

 of which he is president. The other 

 oflBcers are: Vice-president, Frances L. 

 Robinson; secretary, William T. Saun- 

 ders; treasurer, Joseph W. Brown. 



Selma, Ala. — Announcement has been 

 made of the marriage of Miss Archie 

 Newman to Carl De Bangue Vineyard, 

 manager of the Vineyard Floral Co., of 

 Jackson, Tenn. The wedding was a 

 beautiful affair throughout and quite 

 worthy of a florist. The church was 

 decorated with palms, ferns and south- 

 ern smilax. The bridesmaids and the 

 maid of honor carried tastefully made- 

 up garden bouquets. The bride carried 

 a splendid shower bouquet. 



Lansing, Mich. — The Smith Floral 

 Co., about September 1, will remove to 

 a new and much better location. A con- 

 tract has been placed with the A. L. 

 Randall Co., Chicago, for a complete 

 outfit of fixtures for the new store. 



Memphis, Tenn. — Mr. and Mrs. Olof 

 Johnson will be at home Wednesday 

 evening, August 10, in celebration of 

 tlioir fiftieth anniversary. In 1871 Mr. 

 .Johnson married Miss Fannie E. Brown. 

 Their present residence is at 1066 North 

 Seventh street. 



Lowgap, N. C. — The firm name of W. 

 M. Woodruff & Son, wholesale packers 

 of decorative greens, of this town and 

 (>alax, Va., has been changed to W. M. 

 Woodruff's Son & Co. T. N. Woodruff, 

 tlie manager of the business since its es- 

 tablishment twenty years ago, still re- 

 mains the general manager, with J. E. 

 Cockorham, a member of the firm for 

 the last five years, as sales manager. 

 This means a slight change in name 

 only. W. M. Woodruff retired from the 

 business eight years ago. Business in 

 their line is above the average for this 

 time of year and they anticipate a big 

 run the coming season. 



