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FLORISTS FIGHT i^ 



FUNGOUS FOES 



In fighting fungi or foes in other forms, the most scientific method is 

 the m/)st successful. Modem floriculture is tested and applied science. Pro- 

 gressive florists are practical scientists and will readily appreciate the 

 value, the money-making power, of the facts presented in this article. 



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CONTEOL of 

 fungous diseases 

 of floricult ural 

 plants in the green- 

 house may be ef- 

 fected in three dif- 

 ferent ways: First, 

 by preventing the 

 fungus from enter- 

 ing the plant; sec- 

 ond, by curing 

 plants already dis- 

 eased; third, by growing disease-resis- 

 tant plants, or by means of breeding 

 and selecting, so as to make susceptible 

 varieties resistant. At the present time 

 the first method given is generally fol- 

 lowed. The preventing of the fungus 

 from entering the plant may be accom- 

 plished in a number of ways. 



One of the most important facts that 

 the florist must remember in the con- 

 trolling of greenhouse diseases is clean- 

 liness. Keep your greenhouses in per- 

 fect condition and you will rarely suf- 

 fer from serious losses. 



A Sanitary Oreenliouse. 



A good habit to cultivate is to pick 

 up all the fallen leaves and rubbish you 

 see in the greenhouse. It is a habit 

 well worth while instilling in 

 the minds of all employees 

 working about the establish- 

 ment. There is absolutely no 

 reason why a greenhouse 

 should not be kept as neat as 

 the shop. Plants, like human 

 beings, should be kept in a 

 thoroughly sanitary environ- 

 ment in order to thrive. You 

 can control, to a large extent, 

 black spot of roses, one of the 

 most common diseases in the 

 greenhouse, by gathering the 

 infected leaves on the plants 

 and on the benches. 



Under the general head of 

 cleanliness be sure to include 

 the removal and destruction 

 of affected parts, such as 

 leaves, twigs or whole plants, 

 the avoidance of disease- 

 bearing material, as old soil, 

 and the prevention of wounds 

 by careful handling. For ex- 

 ample, the fungus causing 

 branch-rot of carnations can- 

 not attack sound plants, but 

 enters only when wounds are 

 present. 



The selection of seeds and 

 cuttings is, in many cases, the 

 easiest and most natural 

 method of control. How many 



florists know, when they purchase 

 seeds, under what cond^oQS and 

 in what localities the seed plants 

 were grown, the percentage that 

 will germinate, or what disease may be 

 carried on these seeds! No doubt a 

 number of serious diseases are carried 

 from one locality to another through 

 seeds and cuttings. One of the best 

 examples of a serious disease being dis- 

 seminated bv cuttings throughout the 

 country is the snapdragon rust, which 

 has now been reported from a large 

 number of states. It is known that 

 fungi are found on the seeds of sev- 

 eral plants, which in one case cause a 

 serious damping off, while later another 

 fungus causes a destructive wilt in the 

 field. 



Clean Seed and Clean SoiL 



Always select your seeds and cut- 

 tings only from the strongest and 

 healthiest individuals and never send 

 out seeds or cuttings from diseased 

 plants. Seed selection ip practiced to 

 a considerable extent in other fields, 

 but there is no line of disease-control 

 requiring more attention, at the present 

 time, among the florists. 



Not knowing under what conditions 



ANNOUNCING A SERIES OF ARTICLES BY 



€LThe Review is pleased to announce an arrangement 

 whereby Mr. Peltier will contribute a series of articles on 

 the sdentific side of plant growing. €LMr. Peltier is well 

 known as Associate in floricultural Pathology at the Uni- 

 versity of Illinois, where there is the most complete equip- 

 ment for the study of the problems of florists to be found 

 at any of the institutions of research and learning anywhere 

 in the United States. <IMr. Peltier's series, of which the 

 accompanying article is the first, will deal with plant dis- 

 eases and their control, with insects and insecticides, with 

 soils and fertilizers, and with the general subject of plant 

 breeding and the development of the special qualities that 

 give a plant commercial value. He win answer inquiries. 



the seeds you obtain have been raised, 

 you must resort to seed disinfection. 

 This has been neglected almost entirely 

 by the florists, although it has many 

 promising possibilities. In seed disin- 

 f «-ction the seeds are subjected to a dis- 

 infectant long enough to kill the or- 

 ganism causing the disease, but not 

 long enough to kill the seeds. The dis- 

 infectants generally used are formalin 

 (forty per cent formaldehyde) and 

 corrosive sublimate. 



One of the most formidable groups 

 of organisms, which cause considerable 

 loss at times in the greenhouse, is the 

 soil fungi. The only efficient means of 

 controlling these fungi is by steaming 

 the soil or by the use of a disinfectant. 

 Steaming the soil is, beyond a doubt, 

 the best method of killing all soil fung^. 

 However, few growers will resort to 

 steam sterilization because of the labor 

 and expense involved. The use of a 

 disinfectant like formaldehyde, while 

 not so efficient, is more convenient and 

 less expensive. 



Oreenliouse Fungicides. 



The application of fungicides has 

 probably, in the past, been the most 

 highly developed phase of disease-pre- 

 vention in plant pathology, but 

 under glass the use of fungi- 

 cides, especially those which 

 discolor foliage, is limited. 



"With fungicides you can pre- 

 vent most of the common spot 

 diseases of floricultural plants, 

 as well as several of the rusts. 

 Among the more common 

 fungicides that you can use in 

 the greenhouse are Bordeaux 

 mixture, ammoniacal copper 

 carbonate, lime-sulphur, potas- 

 sium sulphide, and flowers of 

 sulphur. 



A number of fungi are able 

 to live for several years in 

 greenhouse soil and the con- 

 stant use of the same house 

 or the same soil tends to in- 

 crease the disease of that crop. 

 As most growers change the 

 soil in the houses every year, 

 they avoid, to a large extent, 

 the soil fungi. However, if 

 you rotate your crops from 

 one house to another yearly or 

 every two years, you will 

 avoid having trouble from 

 year to year from air-borne 

 fungi. 



Two years ago the federal 

 government established the 

 plant quarantine act, and with- 



