494 Rejport of the Mycologist of the 



who have made the so-called tests of fungicides had made careful 

 experiments such as they might have made with very little extra 

 labor and expense we would be far in advance of our present 

 position in this struggle with rust. In a properly planned experi- 

 ment all conditions, save the one being tested, should be parallel; 

 for example, if testing the value of any fungicide as a remedy for 

 carnation rust there should be used at least two plots of plants. 

 These two plots should be of the same variety, in the same house 

 and treated in the same way as regards soil, watering, manuring, 

 supporting, etc. They should be in all respects as nearly alike as 

 possible save thai one is s]»rayed regularly with the fungicide 

 while the other is untreated. Should any difference appear be- 

 tween the two plots later they can then with good reason be 

 attributed to the action of the fungicide. 



Recommendations for Treatment. 



As far as possible grow varieties which are least subject to 

 rust. 



Do not propagate from diseased stock and bear in mind that 

 plants may be diseased and not show it. If there is any possi- 

 bility of rust being present dip the cuttings in potassium sul- 

 phide solution* (1 oz. to 1 gal.) to kill such spores as may cling 

 to the cuttings. " Strike " the cuttings in fresh sand.f 



Throughout the entire life of the plants, from the time the 

 cuttings are " struck " until the plants are exhausted the follow- 

 ing spring, spray weekly with copper sulphate (2 lbs. to 45 gal.) 

 or potassium sulphidet (1 oz. to 1 gal.). Copper sulphate is 

 preferable because it is cheaper. It may be asked if it wdll pay 

 to spray varieties which are not much subject to rust, such as 

 Wm. Scott, Albertini, Portia, etc. Yes, it probably will pay be- 

 cause spraying will have a tendency to keep down spots,§ fairy 

 ring, Botrytis and Cladosporium. 



* It may be found best to soak cuttings one-half hour in this sohition or a weaker one, but 

 as yet wenre not positive that such treatment will not injure the growth of the cuttings. 



("Satid which has been used before is likely to contain spores of various fungi besides rust, 

 particularly spores of the cutting-bed fungus Vohdelln Diavthi. 



t This must be prepared fresh each time. Also the chemical must be excluded from the air. 

 It is a eood lOan to buy 'it put up in a pound cans. One can of this size is the (Quantity 

 rei|<'ired for ;i J')arrel of water. 



§ There is scarcely anyi'diieot' experimental evidence to show that either of the above 

 furgicides will control the diseases mentioned. The statement is based on general principles. 

 In Revue Horticole for 1804. p. 411, Prof. IMagnin reports that copper sulphate, even in very 

 dilute solutions, prevented the germination of the spores of fairy -ring fungus. Heterosporixim 

 echinulitnm . 



