FUNGUS DISEASES 143 
words, burn the plants as soon as they become brown 
and lifeless, for any delay means the breaking up of 
the brittle, rusty plants, and a heavy sowiny of the 
spores upon the ground. If the fire could go over the 
whole field of standing brush, that would be the most 
effective destruction. At best, with these precautions, 
many of the spores will get scattered upon the soil, 
and it would be well to sprinkle a thin coat of lime 
upon the ground and leave it there during the winter. 
If this could be followed by a turning under of the 
surface soil in the spring, it would bury the spores 
that might still be living, so that they would be out of 
reach. 
Cultivation and trrigation.—It has been observed 
that the injury to asparagus plants, as a result of rust, 
has been confined to dry soils, although there are 
places where beds in close proximity showed remark- 
able differences as to infection; and that robust and 
vigorous plants, even where cultivated on apparently 
dry soil, are capable of resisting the summer or inju- 
rious stage of the rust. 
In view of all the experiments so far made, and the 
experiences of practical asparagus growers, Stone and 
Smith conclude that: ‘‘ The best means of controlling 
the rust is by thorough cultivation in order to secure 
vigorous plants, and in seasons of extreme dryness 
plants growing on very dry soil with little water- 
retaining properties should, if possible, receive irriga- 
tion.’’ 
From a knowledge of the occurrences of the rust 
in Europe, and from observations made in Massachu- 
setts, they are led to believe that the outbreak of the 
