154 GARDENING DIFFICULTIES SOLVED 



Care must be taken after the Potatoes have been treated with the 

 formalin solution that they are not used for food, and they should 

 not be placed in sacks or hampers that have contained scabbed 

 Potatoes. Land that has produced scabbed Potatoes should not be 

 planted with Potatoes for several years afterwards. Beet, Swedes, 

 Carrots, and Cabbages are also affected by the fungus ; cereals may 

 be sown with safety on infected land. In the case of gardens and 

 small allotments, where, of necessity, Potatoes are grown every year, 

 the trenches in which the Potatoes are planted should be sprinkled 

 with flowers of sulphur, this being done by means of a bellows 

 apparatus. As you require 45 bushels of Potatoes for table use, you 

 would need to plant j acre, the produce of 1 acre of late Potatoes 

 being about 6 tons, and 45 bushels equals 22^ cwt, so that some 

 margin will be left in excess to account for small or otherwise 

 unusable tubers. It certainly pays allotment holders to grow their 

 own Potatoes with land at Is. per rod, 8 per acre, also many private 

 and public establishments ; your cost of labour, however, is high, 24s. 

 per week, and that may make just all the difference between econo- 

 mical and unremunerative production. ~ 



The Carrot Fly 



Q. Please say what worm this is attacking my carrots. Some of 

 the roots are a rusty brown colour, while others are rotten. A. T. S., 

 Colchester. 



A. The worm is the larva or maggot of the Carrot fly. The fly 

 does not, as a rule, attack them until the end of May. The flies 

 appear in spring, and when the Carrot roots are well established the 

 flies lay their eggs on them just below the ground. When full fed 

 the maggots leave the roots for pupation in the soil ; the pupa case 

 is light brown in colour, horny, and striated. There are several 

 generations during the summer, but it is a remarkable fact that Car- 

 rots sown after the middle of July are seldom attacked, and good, 

 useful Carrots are obtained by sowing about that time, say after 

 early Potatoes. The freeing of the ground from pupae by dressing 

 with gas lime in winter is an old fashioned preventive, but as the 

 fly infests other umbelliferous plants the thing is to keep a sharp 

 look out for the flies, and when they are seen about or on the Carrot 

 plants, spray these with a solution of paraffin emulsion, 1 part of 

 emulsion to 20 parts of water. This can be put on with a syringe 

 having a spraying nozzle. To act preventively, spray the Carrot 

 bed, after sowing, with the paraffin emulsion ; spray again with it 



