84 Report <ni a Tr'ad of Tarmi Fdl '^Z>/xr.s'" 



Apparently, however, there are no published records of any trials of 

 this method having ever been made in this country. References in 

 British horticultural literature, and in reports on insect pests, to the 

 use of tarred felt discs are very meagre and not very encouraging. 



As numerous complaints of damage and losses sustained by growers 

 owing to the depredations of the Cabbage- Maggot are continually being 

 received, together with requests for information how to deal witli the 

 pest in question, the desirability of testing here the method which has 

 proved so successful in America thus becomes apparent. 



During successive seasons in my own garden I have lost considerable 

 numbers of cabbages and cauliflowers owing to attacks of the Cabbage- 

 Maggot and I had already decided to test the American discs when 

 Dr A. D. Imms suggested that I should test them on a fairly large scale 

 in a local market-gardem. Arrangements were therefore made with 

 a market-gardener to rent from him a piece of land and the work was 

 commenced in the spring of 1916. 



Description of the Experiments. 



The tarred felt discs were obtained from the United States where 

 they are regular articles of commerce. They were not the hexagonal 

 form usually figured and described but they were square, being 2| inches 

 each way with only two slits -a long slit extending from the middle of 

 one edge to a point half- an- inch beyond the centre of the disc, and 

 a short slit three-quarters of an inch long crossing the long slit at right 

 angles in the centre of the disc (Fig. 3). 



Two separate pieces of land situated at Northenden, Cheshire, were 

 rented from Mr Chas. Heywood, a market-gardener, who undertook to 

 prepare the land and perform the necessary operations of cultivation, 

 planting, etc. The tests were made on both cabbages and cauliflowers 

 and the two plots of land were about sixty yards apart. The land on 

 which the cabbages were planted was under cauliflowers in 1915 and 

 the crop then suffered severely from maggot attack, from two to three- 

 fifths of the plants being lost owing to this cause. This piece of land 

 was selected in order to ensure, so far as possible, a heavy infestation 

 of maggots. 



A heavy dressing of well-rotted farm-yard manure was spread over 

 the land towards the end of April ; this was then ploughed under, the 

 land afterwards harrowed down and then rolled in order to consolidate 

 the soil — which is very light in texture — and to render conditions 

 favourable for placing the discs as flat as possible. 



