SMUT, RUST, AND MAGGOT. 43 



be spread abroad, well aired, and turned carefully and often 

 until thoroughly dried. If they are handled while frozen, 

 they will be very likely to decay as they thaw out. 



SMUT, RUST, AND MAGGOT, 

 T^HE ONION-CROP is sometimes severely injured by a disease 

 resembling mildew, which is beUeved to be caused by 

 animal parasites. The tops of the leaves die, and the whole 

 plant is more or less covered by a white blast. From the 

 effects of it the onions almost cease their growth, and the 

 crop finally obtained is small in size. It is more frequent in 

 extraordinary wet seasons, or during a long spell of " dog- 

 days," and is more common on old beds than new. The 

 best remedy yet known for old beds is to carefully remove 

 from the bed and destroy at the close of the season all 

 diseased bulbs, as they will be likely to spread the disease by 

 giving it a lodgement in the soil ; then run the plough a 

 little deeper, and thus mix in a little new soil. A liberal 

 application of air-slacked lime to the leaves as soon as the 

 white blast appears, is said to kill the parasites that cause it. 

 " Smut," as a black discoloration of the leaves is called, is a 

 deadly enemy. Whenever this appears, the bed must be 

 changed to a new location, and the land be cultivated to 

 other crops for four or more years before it can safely be 

 replanted to onions. 



The onion-maggot is hatched from the eggs of a fly, 

 which are deposited in the plant (not the seed) very near 

 the surface of the ground. Its presence may be detected in 

 the crop when very young by the sudden turning yellow and 

 falling over of the plant, which, if the attempt is made to 

 puU it, will usually break off near the surface ; and, on 

 squeezing, several small maggots will present themselves. 



