210 BOARD OF AGRICULTURE. [Pub. Doc. 



must be made at intervals of from one to three weeks, 

 according as the insects increase or as the weather may be 

 favorable or mifavorable for the growth of the blight or rot. 



Celery. 



Attackhig the celery we have the celery caterpillar 

 (Paptlio asterias)^i]ie celery leaf blight (Septoria peiroseUni 

 var. apii) and the celery leaf rust ( Cercospora apii) . 



The celery caterjnllar seldom does much injury, and is 

 destroyed by hand picking. The rust and leaf blight are 

 more common, and often cause serious injury. They both 

 come on in hot, dry weather, and especially where the sup- 

 ply of plant food is small or reduced by the lack of moisture 

 in the soil to render what there is soluble. 



The treatment of these diseases with the Bordeaux mixture 

 has not been productive of quite satisfactory results ; yet it 

 is believed that if the plants are sprayed in the seed bed, and 

 then two or three times after planting in the field, much 

 benefit will result. When either of these diseases appear, 

 if deep cultivation is practised l)y means of the plough or 

 deep-working cultivators close up to the plants, and some 

 quick-acting fertilizer is applied, the plants generally recover 

 and grow to maturity without further injury. 



Cabbage. 



The cabbage worm {Pier Is rapce) is the insect most de- 

 structive to the cabbage, and the club root (Plasmodiojyhora 

 brassicce) the most troublesome fungous growth. 



For the cabbage worm we find pyrethrum or Persian in- 

 sect powder, if fresh, extended by adding twenty to fifty 

 parts of air-slacked lime or flour, and dusted into the head 

 with the common sulphur bellows, a certain, harmless and 

 cheap remedy. Paris green 77iay be used until the heads 

 begin to form, but after that time is dangerous, and at any 

 time we would not advise its use unless absolutely necessary. 



The club root is a fungous growth that causes the tubercles 

 or swellings on the roots of the turnip and cabbage, and is 

 propagated on the roots of many other cruciferous plants, 

 like the mustard, shepherd's purse, etc. It also propagates 

 in composts that contain any waste of cabbage or turnip. 



