1908.] 



Yellow Rattle. 



115 



disease was only arrested in the plant showing the first signs. 

 The plants sprayed at a later stage showed signs of a check, 

 but, though v the spraying was continued, the disease broke 

 out again and again. On microscopic examination it was 

 found that the tissues of these plants were permeated by the 

 mycelium to such an extent that the spray did not kill the whole 

 of it, and in a few days the fungus had recovered its vigour 

 and the disease reappeared. This emphasises the necessity of 

 keeping a close watch upon the plants, and spraying imme- 

 diately the spots appear. Spraying with a 4 per cent, solution 

 resulted in injuries to young leaves and shoots, and should 

 not be practised. 



The following points may be gathered from these experi- 

 ments : — 



(1) Plants once attacked can only be saved when sprayed 

 immediately the first signs of disease are noticed. The plants 

 should be sprayed with a 3 per cent, solution of Bordeaux 

 mixture early in the morning every second day for two weeks. 

 The spray should be in the form of a fine vapour falling upon the 

 plants like a natural dew. 



(2) Badly attacked plants might be cut back, or, better 

 still, uprooted and burned. 



(3) Any wires and props used in the houses should be slowly 

 drawn through fire, in order to kill the spores adhering to them. 



(4) The top soil should be removed and mixed with fresh 

 lime, in the proportion of about one barrowful of lime to five 

 of the soil. It can be replaced after the lime has slaked. 



(5) When planting young tomato plants, pulverised lime 

 should be scattered on the ground round the stems. 



(6) Tomato seed from infected areas should not be used, 

 but if it is it should be steeped for one hour in a 5 per cent, 

 solution of copper-sulphate and dried before sowing. 



YELLOW RATTLE. 

 (Rhinanthus Crista-galli, L.) 

 A weed which is frequently a considerable trouble to farmers 

 is that known by the common names of Yellow Rattle, Rattle 

 Grass, Cock's-comb, or Horse-penny, its botanical name being 

 Rhinanthus Crista-galli, L. 



H 2 



