Fkbihakv 211, 1!M:: 



The Weekly Florists' Review, 



417 



New Carnation Viola Allen. 



forward for the consideration of the 

 society, "Sterilization as a Preventive of 

 Stem-IJot." I believe this matter was 

 discussed at the Biiltiniore meeting, but 

 I liiid no one «'ho has carried out a thor- 

 ough test of sterilizatitni. and, while our 

 experiuients have not been by any means 

 us thorough as they might have been, 

 yet their extensiveness may make them 

 valuable and I take pleasure in present- 

 ing a report of our work. 



It has been my good fortune, the past 

 three years, to be a.ssociated with Dr. 

 G. E. Stone, of the Hatch Experiment 

 Station of Amherst, JIass., and it is to 

 him that I owe my interest in steril- 

 ized soil. While a student at college I 

 followed the experiments of Dr. Stone 

 on the cultivation of lettuce, and taking 

 at the same time the study of carnation 

 diseases, I found that we are fighting a 

 common enemy with the lettuce growers, 

 namely, the sterile fungus "Rhizoctonia" 

 which causes the so-called "wet-rot" of 

 carnations. Tliis has been described in 

 Bui. 180 of the Cornell Experiment Sta- 

 tion and no doubt this fungus is well 

 understood. I will not, attempt a de- 

 scription of it, but I wish to quote a 

 paragraph from that bulletin, which 

 reads: ''This stem-rot is one of the most 

 troublesome of the carnation diseases 

 and probably occurs throughout the 

 whole United States wherever the car- 

 nation is grown. Frequently entire 

 houses of mature plants are de- 

 stroyed by it. During the past au- 

 tumn it appears to have been unusually 

 prevalent. It attacks plants of all ages 

 both in the field and in the greenhouse, 

 and is one of the principal causes of 

 damping off of carnation cuttings. In 

 greenhou.se benches it spreads slowly 

 through the soil from one plant to an- 

 other; but according to our experiments 

 never througii tlie air as from one bench 

 to another. lis principal mode of dis- 



semination is by means of affected plants 

 and cuttings." 



This fungus also attacks lettuce and 

 Bui. 09 of the Hatch Experiment Sta- 

 lion treats of the attack of the fungus 

 on lettuce in a very clear and concise 

 manner. Comparing these two and 

 knowing that sterilization prevented the 

 attack on lettuce I became convinced 

 that "wet-rot" of carnations could 

 largely be prevented by the same meth- 

 od. There is, however, an important 

 point to be taken into consideration and 

 lliis is. that in the growing of lettuce 

 the seed can be started in sterilized soil 

 and the plants grown in it from seed, 

 while with carnatioris the planting in 

 the field would subject them to the at- 

 tacks of the fungus and cau.se error in 

 our work even were they rooted in ster- 

 ilized sand and potted in sterilized soil. 



There is another rot of carnations 

 with which we are all acquainted and 

 this is the subject of an article by Mr. 

 Win. C. Sturgis. which may be found in 

 the Report of the Connecticut Experi- 

 ment Station for 1897. This is known 

 as "dry-rot" and I again take the lib- 

 erty of quoting: "The spores of the 

 fungus are apparently able to retaih 

 their vitality for several months and 

 to live over winter in the earth. The 

 fact that the disease can be transferred 

 to sound cuttings by planting the same 

 in soil containing vegetable matter and 

 impregnated with spores of the fungus, 

 indicates that the spores can thrive in 

 such soil and thence gain access to the 

 tissues of the plant. Consequently when 

 the disease has been present in the green- 

 house the old soil should be completely 

 removed, the house thoroughly fumi- 

 gated with sulphur and the benches re- 

 filled with fresh soil. Abundant moist- 

 ure and an excess of vegetable matter in 

 the soil afford conditions favorable to 

 the development of this Fusarium. These 



should be avoided as far as possible. 

 Wherever practicable sterilizing the 

 soil by means of steam or hot air would 

 be effective in preventing the attacks of 

 the fungus. In ^his ease, diseased cut- 

 tings could be the only possible cause 

 of contamination." 



The preceding shows that we are work- 

 ing under difficulties and that our tests 

 are liable to error, for I have no way of 

 knowing what percentage of my plants 

 were already attacked by rot when they 

 were benched, but I will give you as ac- 

 curately as I can the facts as they 

 really are and you may judge from them 

 whether there was sufficient gain to war- 

 rant the expense. 



We have this year four houses, each 

 three hundred feet in length, devoted to 

 carnations. These differ in width, being 

 thirty-six. thirty, sixteen and sixteen 

 (cet respectively. The first house planted 

 was one of the sixteen-foot houses and 

 in this there are two benches, four feet 

 four inches in width, running the length 

 of the house, a cross-walk at; the center 

 dividing these, making practically four 

 benches, each a trifle less than one hun- 

 dred and fifty feet in length. Let us 

 follow the method of handling a house, 

 and for the sake of convenience call the 

 benches by numbers. Let us designate 

 the right-hand benches Nos. 1 and 2 

 and the left-hand benches Nos. 3 and 4. 

 The soil is wheeled in on the left-hand 

 benches and we fill the right-hand 

 benches as we would fill them with no 

 reference to sterilizing; filling each 

 bench even with soil after putting about 

 an inch of well rotted cow manure in the 

 bottom. We then lay our system of 

 coils and after putting on eight-inch 

 side boards we fill the soil for bench 

 No. 3 and bench No. 4 into Nos. 1 and 2, 

 or rather, Nos. 1 and 2 extended but in 

 reverse order; that is, with the manure 

 which is to go into the bottom of the 

 other benches on top. This is now ready 

 for the steam, which is gotten up and 

 turned on by the night man, as we usu- 

 ally do this work at night, and when 

 steam at a pressure of from thirty 

 to forty pounds has been forced through 

 the soil for a couple of hours, complete 

 destruction of all animal and vegetable 

 life is assured. 



Now to describe the coils. We run a 

 temporary main from the boiler of 24- 

 inch pipe and extend this through the 

 center walk the length of the house. At 

 distances of fifty feet we put in tees and 

 connect at these points with the coils by 

 means of hose, which can be obtained 

 especially adapted for the purpose. The 

 coils are made up of headers and perfor- 

 ated pipe. The length of the header 

 we vary with the width of the bench, 

 ■screwing on nips and tees as needed. 

 This is necessary, for the coil must be 

 as wide as the bench to insure approxi- 

 mately perfect sterilization. At right- 

 angles to the headers and parallel to 

 each other we run perforated pipe. These 

 are about ten inches apart. Thus, a 

 bench four feet four inches in width 

 would require a header four feet two 

 inches in length and five lengths of \i- 

 inch perforated pipe. We have found 

 that we can handle steam to the best 

 advantage by having headers fifty feet 

 apart and by connecting each header 

 with the main; and we have also found 

 it economy to have the whole house 

 ready and to sterilize it all at the same 

 time, as it requires but little more steam 

 to do this than to sterilize a single- 

 section, and time will be lost waiting 

 for the soil to become cool enough to 



