MANGOLD "leaf-blister" MAOaOT. 89 



yet the knowledge that it lessens the absolute amount of Mangold Fly- 

 infestation, and very greatly helps the plants to bear up under it, might 

 sometimes save unnecessary ploughing up of a crop just on the verge 

 of recovery. 



The points of treatment have already been so frequently noted in 

 detail, that I only add the following extract from my own leaflet on 

 this attack giving the principles of prevention and remedy. 



The only direct measures of remedy which appear to have been 

 noted are, — Istly, the use of such fertilisers to the attacked crops as 

 may push on vigorous growth, and so carry the plant through the time 

 of injury ; and 2ndly, endeavouring to get rid of the maggots by 

 pinching them in the blisters; nipping out the infested bit of leaf; or 

 by drawing the infested plants when the maggot attack comes so early 

 that the crop will bear thinning. This last plan answers if the workers 

 are well overlooked to make sure of the infested plants being drawn 

 and destroyed, before the maggots can get away from the leaves to go 

 through their changes in the ground. 



Any fertilising application will do good, which will act at once in 

 furnishing nourishment to the plant, and thus keep it continually 

 replacing by new growth the leafage which is destroyed by the maggots ; 

 nitrate of soda appears to do best, but, as the action of all these 

 fertilisers depends on having rain at the time to wash them down to 

 the roots, it is better to have previous good treatment of the land to 

 trust to. 



For this (where it can be done) autumn cultivation has been found 

 to answer, and " the use of a mixture of farm manure, applied in the 

 autumn as soon after harvest as possible, and a fair dressing of super- 

 phosphate, &c., put on with the seed," has been found to do well. 



Dustings of various kinds have been tried, but, as these do not 

 reach the under side of the leaves where the eggs are laid, nor the 

 inside where the maggots feed, it seems likely that they only act by 

 fertilising the land, or (as with paraffin in ashes) by causing a smell 

 different to that which attracts attack. — (See ' Leaflet on Mangold 

 Maggot,' pp. 2 and 3, by Ed. Printed for gratuitous distribution). 



Note. — As it may be of some interest to refer to what must be 

 amongst the first regular agricultural notices of Mangolds as a newly 

 introduced crop in this country, and the attention this excited, I add 

 a few extracts on the subject in the Appendix, taken from numbers of 

 the ' Farmer's Journal and Agricultural Advertiser ' for May 8th, 1815, 

 and April 8th, 1816.— Ed. 



