106 INSECTICIDES, FUNGICIDES, AND WEED KILLERS. 



Dubieuil, Fauchet, and Girardin have confirmed these figures and give 

 264-440 lb. }jer acre as a suitable dose. 



Use against Injurious Plants. — Salt in excess is injurious, and 

 certain plants stand it with difficulty. Wendler found common salt 

 an excellent means of destroying charlock. 



Destruction of Moss in Meadows and Weeds in Walks. — A 

 strong dose of salt has a corrosive action on delicate plants ; thus 

 mosses and horse-tails which invade meadows succumb long before the 

 graniineae. Used on meadows and fields in a dose to kill moss, it only 

 retards the growth of the graminea^ ; applied on corn fields, it keeps 

 the stem shorter, imparts a certain rigidity and prevents laying. 

 Watering paths with a 10 per cent solution is the method used to 

 destroy weeds ; unfortunately it only destroys them momentarily and 

 imperfectly because they spring up again as soon as rain comes to 

 wipe out the treatment. 



Use of Common Salt against the Diseases of Plants, — Bac- 

 terian diseases of the potato, scab, crevices, etc. — Becquerel experi- 

 mented with common salt on the diseases of the potato. This pi'oduct, 

 in big doses, being an antiseptic, it might, therefore, prevent the ex- 

 tension of these diseases. The potatoes were planted in winter, and 

 to prevent the frost getting at them the tubers were planted at a depth 

 of 15 inches, with 10 grammes of salt, the others without any saline 

 manure. In the salted ground the potatoes could be harvested two 

 months before the normal time, and whilst on the ordinary soil there 

 were 10 per cent of diseased potatoes, on the soils supplied with salt 

 all the tubers were sound. Techemacher and Neumann came to the 

 same conclusion, and according to Peters there is even an increased 

 yield, but on the other hand a diminution in the total amount of starch. 

 The same result occurs, therefore, as with the beet ; the improvement 

 brought to bear on this crop by common salt, and the increased yield 

 are rather illusory, since as Grouven, Pingen, and Hert have shown, 

 the weight of the beet increases whilst that of the sugar diminishes. 



Peronospora Viticola, De By. (mildew of the vine). — Recommended 

 in Germany towards 1882 the spraying of vines with a 2 per cent 

 solution of common salt : having given no result, was soon abandoned. 



Bust of Cereals. — Solutions of common salt were tried to combat 

 this disease on the adult plants. Feburier and Phillipar obtained 

 good results by spreading either salt or a mixture of salt and lime on 

 the crop, but this improvement has been disputed by Loverdo. 



Use in the Destruction of Insects. — Salt is not an insecticide, 

 but its presence in the soil sometimes renders a sojourn there im- 

 possible or disagreeable to certain insects. 



Aijriotes lineatus, L. (wire-worm). — The larvae of this insect have 

 been combated by spreading a strong dose of salt on the fields. Com- 

 stock and Slingerland found that by mixing 10 tons of salt per hectare 

 (4 tons per acre) with 10 centimetres (4 inches) of the arable surface 

 soil these larvte died ; with only 7^ tons per hectare (3 tons per acre), the 

 effects were imperceptible. Unfortunately to obtain good results such 

 large doses of common salt must be used that growth cannot take 

 place normally ; hence it has been advised to apj)ly salt during the bare 



