77 8 ADDENDUM 



impervious to the attacks of the fly when the egg-laying time 

 arrives. One of the several soil disinfectants should also be dug 

 into the soil or sufficient lime and salt to whiten the ground spread 

 on the surface and forked in. Plants raised in the autumn or those 

 raised under glass in the early part of the year are seldom attacked ; 

 they are too hard and buried too deeply for the insects to get at 

 them. In many cases where the outdoor sowing of onions has been 

 a failure, growers have abandoned this mode of culture and raised 

 the plants under glass instead. These when large enough are 

 pricked into boxes, and in some cases potted off singly and grown 

 in frames. After having been well hardened off they are planted 

 out during April. It has been found that grown in this way the 

 losses have been reduced to a minimum. A grower of our acquaint- 

 ance uses nothing but soot, and he never has any trouble either 

 with the onion fly or the carrot fly. A good preventive against 

 the first inroads of the fly is to spray the young plants every few 

 days with an emulsion made by boiling I Ib. of soft soap in two 

 quarts of water, adding half a pint of paraffin, then six gallons of 

 water, working the whole through a syringe until it is a frothy 

 mixture. If after the spraying is completed a good dressing of 

 old weathered soot is dusted over the moistened plants the onions 

 should be in great measure protected from the fly. 



Potatoes, Wart Disease of. This, known as Synchytrium 

 endobioticum, is the worst of all diseases that affect vegetables. 

 The unfortunate part of it is that unless checked it will very soon 

 spread over a wide district. It is easily recognised by the ugly 

 excrescences like warts that appear in the eyes of the tubers. 

 When once a tuber or tubers have fallen a prey to this disease 

 these tubers are of no value, and should be at once burned to 

 prevent the spores getting into the soil. Very often the stems of 

 the plants are attacked, this being indicated by greenish-white 

 growths thereon. The warts on the tubers are at first of a dark- 

 brown colour and firm, but as the season advances they change 

 to almost black and are quite soft, finally rotting away and in 

 decay emitting a most unpleasant smell. This is the time the 

 spores are mixed with the soil, where they remain dormant, but 

 still capable of causing serious loss should potatoes be planted on 

 the infected ground. Never save any seed from the wart-infested 

 tubers, as this is a certain way of still further spreading the disease. 

 Potato growers both amateur and professional should look over 

 their crop, not only during the growing period, but afterwards 

 when the tubers are in store, and if any tubers with the least 

 symptoms of the disease are found they should report the same, 

 as wart disease is notifiable and severe penalties are attached to its 

 wilful concealment. All infested tubers should be burned, and 

 the ground from which they have been lifted dressed with gas- 



