REPORT OF THE HORTICULTURIST HI 



SESSIONAL PAPER No. 16 



The summer stage follows this spring form, though the two may overlap, both 

 stages existing at the same time in the same plant. The brown colour of the aspara- 

 gus fields produced by the ripening spores of this second stage, the ' red rust' form, 

 and the rapid spread of the disease at this time, cannot fail to attract attention to the 

 fields affected. The spores from this stage discharge from slits in the asparagus 

 stems, not from clusters of pustules, and are so numerous that they cover workmen 

 and tools in the fields with a heavy coating like brick dust. 



The third stage, known as the ' winter stage,' follows the one just described, 

 either in the fall or even in the summer if the lessened vitality of its host plant be- 

 tokens approaching death. It is by the spores of this stage that the fungus is carried 

 over the winter, so Nature provides for their formation whenever the existence of 

 the fungus is threatened by the death of the asparagus plant it infests. The third 

 stage differs from the second only in the character of the spores. In the summer stage 

 the spores are one-celled and thin-walled, while in the winter stage they are two-celled, 

 thick-walled and of such a dark brown colour that the stage is known as the ' black 

 rust.' Both summer and winter spores may often be found in the same slit in the 

 asparagus stem.' 



The drying up of the stems and foliage of the asparagus plants before the season's 

 growth is made, weakens them very much and on this account the crop of young 

 shoots the following spring i3 much lessened and becomes still less every year the 

 disease affects the plants. Owing to its smooth leaves and stem, asparagus cannot be 

 sprayed to advantage with Bordeaux mixture, as it runs off when applied. At Geneva 

 a combination was made of a ' resin-lime' mixture and Bordeaux mixture, the stock 

 solution of the former being made as follows : — 



Pulverized resin 5 lbs. 



Concentrated lye 1 lb. 



Fish oil or any cheap animal oil, except tallow 1 pint 



Water 5 galls. 



< 



It takes about two hours to prepare this mixture. The oil, resin and one gallon 

 of hot water should be placed in an iron kettle and heated until the resin is softened, 

 after which the solution of concentrated lye, or potash, should be carefully added, 

 and the mixture thoroughly stirred. After the lye has been added, add four more gal- 

 lons of hot water and allow the whole mass to boil until the mixture will unite with 

 cold water, making a clear, amber-coloured liquid. When through boiling if there ia 

 not five gallons of the mixture add water enough to make that quantity.' 



Two pounds of this stock solution were added to the Bordeaux mixture before 

 spraying. The following quotation gives the dates of spraying and the results ob- 

 tained : — 



' After the last cutting was made the brush was allowed to grow for four weeks, 

 after which five sprayings were given, the first on July 28. Alternate rows were spray- 

 ed and left as checks. The rust showed on the unsprayed rows August 19, and by 

 August 24 had spread to all parts of these rows. They were killed by September 10. 

 The sprayed rows remained green until the middle of October, but it was only the 

 growth made between July 1 and August 10 that survived the attacks of the rust until 

 October 15 ; that is, a growth that was completed, hardened and thoroughly sprayed 

 before the rust struck the bed. All the new sprouts which came up in the sprayed 

 rows after the rust appeared in the field were destroyed.' 



' The results proved that in the case of every unsprayed row the yield in 1900 

 was less than it was in 1899, the decrease on the seven rows being 179 pounds. On the 

 sprayed rows, on the contrary, there was an equally constant gain in yield of from 11 

 to 22 pounds to the row, the total increase being 110 pounds.' 



The results obtained at the New York Experiment Station prove that the disease 

 can be lessened materially by spraying, and as the loss to asparagus growers in Can- 

 ada is likely to be very great from it, something should be done at once to chsck it» 



