120 GARDEN FARMING 



when it first makes its appearance, its presence on the plant after 

 the cutting period to an extent sufficient to cause premature ripen- 

 ing of the plants, shortens the succeeding season's harvest. The 

 remedial measures used in the control of this pest are therefore 

 directed to the securing of a strong, vigorous growth after the 

 close of the cutting season. The treatment employed consists of 

 thoroughly spraying the plants at frequent intervals with Bordeaux 

 mixture. This helps to prolong the growth of the plants and thus 

 enables them to store food for the production of the following 

 season. Another precaution is to cut carefully and burn all tops 

 without removing them from the field. A light sprinkling of straw, 

 to insure complete singeing of the soil surface, is an advantage. The 

 reason for this treatment is the fact that the spores of the rust 

 are carried over on the diseased stalks. The more completely the 

 stalks and all vegetation in the field are destroyed the less will be 

 the danger of infection for the succeeding crop. The treatment is 

 in the nature of sanitation rather than a remedy. 



The only means of securing relief from this disease is the de- 

 velopment of disease-resistant strains and varieties. The fact that 

 there is a marked difference in the ability of individual plants to 

 resist the rust leads to the belief that a resistant form will soon 

 be developed. 



Asparagus rust (Pticcinia asparagi} is caused by a fungous para- 

 site upon the asparagus plant. It attacks the bushy tops which 

 come up in the summer after the cutting season has closed. If the 

 disease is severe, it shortens the growing period of the plant, thus 

 preventing the normal elaboration and storage of food in the roots, 

 and in this way indirectly shortens the succeeding season's cut. 

 The rust attacks plants of all ages, causing enlargements which 

 are somewhat elongated and which later burst open, exposing a 

 reddish granular surface. This form is called the summer, or red, 

 rust. This develops from the spring rust, which may be carried 

 over on dead tops or other refuse from the patch. Red rust is 

 followed by the so-called fall, or black, rust, which is simply a further 

 development of the same disease appearing toward the end of the 

 growing season. This form may occur at any time during the sea- 

 son, although, as a rule, it is most noticeable during the autumn. 

 The dark color is due to the black spores of this form of the rust. 



