486 



HOKTICULTUEE 



April 14, 1917 



l^JO^A/ 



IVERY 



CYCLAMEN GIGANTEUM 



strong tianspliiuti-'d seedliugs, 4 to 5 leaves, ready for SVi 'n,rh pots: Glory of Wandsbek, Christmas Cbeer, Daybreak, Rose 

 vou Marientbal, Pure White, White-Pink eye. For the past 7 years we have beeu improving the Cyclamen, so we feel con- 

 Hdent that you can get no better strain anywhere ; $S.O(i per 100, $75.00 per 1000. 



BEOONIA GLORY OF CINCINNATI: Strong young plants I'm- ^'rowing on, ready for :'. inch pots; $15.00 per 100. 

 BEGONIA MELIOB (something better): This begonia was introduced by us in 1914; it is "better" as its name indicates. 

 No other flowering plant will last so long in bloom as this variety ; strong young plants reaily for ;i inch pots, $20.00 per 100. 

 BEGONIA MRS. J. A. PETERSON (our latest novelty) : The gem of Begonias. Flowers deep cerise, with glossy iridiscent 

 bronze foliage. Awarded Silver Medals at New York and .San Francisco. Young plants ready for 2% inch pots, $20.00 per lOO. 



The Early Plants are the Best 



CASH WITH ORDER FROM I'NKNOWX CORRESPONDENTS. 



J. A. l=>E-rE:RSOIM & 



IVHOLESALE PLANT GROOVERS 



3132 McHenry Ave., Westwood, 



IMS 



CINCINNATI, OHIO 



FLORICULTURAL PATHOLOGY IN 



THE UNIVERSITY OF ILLINOIS. 



The work in Floricultural Pathology 

 is directed along three lines, — the diag- 

 nosis and suggested treatment of di- 

 seases of floricultural plants, the diag- 

 nosis of plant diseases other than 

 floricultural ones upon a request 

 for such information, and the ex- 

 perimental investigation of those di- 

 seases which at present are causing 

 the most serious loss to the grower. A 

 report upon some phases of this work 

 which may have its practical applica- 

 tion follows below. 



Caknation Yellows. Much of the 

 conflicting evidence upon this disease 

 among growers and pathologists Is 

 due to the similarity between "Yel- 

 lows," "Bacteriosis" and "Stigmonose." 

 In fact, at certain stages of develop- 

 ment it is almost impossible to dis- 

 tinguish between the three without re- 

 course to the microscope and the pure 

 culture methods of the pathologist. A 

 report of the work upon "Yellows," giv- 

 ing the characteristics which distin- 

 guish this disease from Stigmonose 

 and Bacteriosis, may be found in The 

 Florists' Exchange, Vol. XLIII, No. 6. 

 and will also be found in the proceed- 

 ings of the American Carnation So- 

 ciety for 1917. Since the preparation 

 of that paper, the data which has been 

 assembled has resulted in additional 

 information. 



If the forcing of the carnation in the 

 early part of the season has resulted 

 In "cropping," and the removal of all 

 flowers has left only the basal portions 

 of the stems, the young shoots develop- 

 ing at this time have always come in 

 yellowed. The tendency to come in 

 yellowed seems to be especially marked 

 if cloudy weather prevails when the 

 young shoots are making a rapid 

 growth, aluiough the results of this 

 may be seen by none except the most 

 careful observer until after the flower- 

 ing buds start to form weeks after 

 The reason for this is that at first the 

 yellowed areas are very inconspicuous 

 and can hardly be seen except when 

 held between tlie eye and the source 

 of light, i^ater, as the leaf grows and 

 becomes thicker, these spots do not 

 grow in thickness with the leaf and, 

 consequently, appear sunken and are 

 conspicuously yellow or almost white. 

 With an abundance of simlight the 

 tendency to come in- yellowed seems 

 reduced. Yellowed plants have been 

 produced experimentally by the re- 



moval of all flowers from plants which 

 have been allowed to crop. The re- 

 moval of the flowers has resulted in 

 the removal of a great area or leaf 

 surface which is necessary for plant 

 growth. The few leaves remaining on 

 the basal portions of the branches are 

 not sufiicient to perform the normal 

 functions of the plant. On the other 

 hand, plants which have never cropped 

 and have always been permitted to re- 

 tain an average amount of foliage 

 have never become yellowed. The evi- 

 dence seems to indicate that yellows 

 is an "indication" of improper treat- 

 ment. The improper treatment men- 

 tioned above has produced badly 

 yellowed plants. Otlier improper con- 

 ditions are probably capable of pro- 

 ducing it. 



Suggestions offered for the preven- 

 tion of this disease are the discarding 

 of unusually susceptible varieties, the 

 taking of cuttings from perfectly 

 healthy and vigorous plants, an early 

 and frequent pinching rather than an 

 occasional severe pinching, the preven- 

 tion of the cropping of the individual 

 plant as well as of the plants as a 

 whole, an evidence of vigorous forcing 

 during the early part of the season, 

 and, individual attention to each plant 

 to prevent the loss of an undue amount 

 of foliage upon the removal of all 

 flowers. 



It is thought, from the observation 

 and the experience of many of the best 

 growers, that an excess of water in the 

 soil and atmosphere at a time when 

 plants are severely or partially cut 

 back will result in the forcing of 

 water, intended for a large leaf area, 

 into the reduced area and result In in- 

 Jury. This may be partially responsi- 

 ble for the more pronounced appear- 

 ance of yellows during cloudy weather. 

 This point, while suggestive, remains 



to be proven experimentally, but 

 might well be kept in mind by the 

 grower. While the work upon yellows 

 is by no means completed, it is deemed 

 wise at this time to give whatever In- 

 formation we have to the grower. One 

 thing to be emphasized is that a plant 

 must receive proper treatment, both In 

 regard to soil fertility and methods of 

 culture, at all stages of growth if it Is 

 hoped to keep it in a healthy condition. 

 Disease prevention is always more 

 logical and satisfactory than disease 

 cure. 



The Fusaridm Wilt of Carnations. 

 This disease, known as "dry stem rot" 

 and "branch wilt," varies in severity 

 in different sections of the country 

 and otten becomes epidemic in nature. 

 In the southern states this is a serious 

 disease which, wlien once started, 

 shows up year after year, being respon- 

 sible for the death or failure of plants 

 to develop after benching. In the 

 Xorth and East, the disease is more 

 spasmodic but otten becomes epidemic. 

 Work, here, in connection witli a sur- 

 vey of the fungi present in greenhouse 

 soils, has shown that this Fusarium is 

 present in abundance in all carnation 

 soils. Infection, however, seldom takes 

 place if the temperature is held as low 

 as is consistent witli the full develop- 

 ment of the carnation and if the spac- 

 ing allows ample circulation of air 

 around each plant. The fungus is 

 most active at high temperature, — a 

 condition to be avoided. Soil steriliza- 

 tion is impractical, for the fungus may 

 be brought into the houses anew on 

 the soil clinging to transplanted 

 plants. However, if the disease has 

 once become serious in a house, it i- 

 recomraended that the plants trans- 

 planted to the field be placed in soil 

 which has not been grown to carna- 

 tions for some time, and that the 



JAPANESE LILIES 



F. RYNVELD & SONS 



25 WEST BROADWAY 



NEW YORK 



