68 ONIONS FOR PROFIT. 



drive the fly away. This simple precaution might be tried 

 also in the onion patch. If it drives the fly away from 

 the one crop, it will undoubtedly do the same service to 

 the other. 



At various times I have observed white grubs, as also 

 wire-worms, etc., feeding at the roots of the onion plants 

 when approaching maturity. I thi-nk they must do con- 

 siderable damage by checking growth, and thus decreasing 

 the yield. Try to get ground that is free from these pests, 

 or to get rid of them by fall plowing. Earth-worms, 

 wherever troublesome, may be disposed of by free applica- 

 tions of lime or lime water as used for the maggot. 

 Potash salts will probably have a good effect in ridding the 

 soil of earth-worms, etc., also. 



There may be other insect enemies, mostly very minute 

 — lice, thrips, or mites ; at least I have heard many com- 

 plaints about them, without ever being able to find any 

 such insects on my onions. Rotation, as for the onion 

 maggot, is probably the surest means of prevention. I 

 can suggest no cure. 



Diseases. 



Among fungous diseases affecting the crop we have 

 two, the onion rust {^Peronospera Schleideniana, Unger), 

 and the smut {Urocystis cepulce. Frost). The former 

 affects the leaves when the onion is beginning to bottom, 

 or later, making them turn yellow, and ending in their 

 decay. It checks the further growth of the bulb. Pull 

 the crop when seriously affected ; cure the bulbs thoroughly, 

 and put them on the market at once. As this can be 

 done quite early in the season, good prices are often 

 obtained. 



I have tried spraying with various fungicides, but with- 

 out being able to check the progress of the disease after it 



