620 



Journal of Agriculture, Victoria. [ii Sept., 191 i 



(nitrates, ammonium salts, asparagin) nor phosplioric food (superphosphate, 

 basic slag), could be absorbed through the leaves in sufficient quantity to 

 make good a deficiency in the soil, however carefully and thoroughly these 

 substances were applied to the leaves. In fact, if superphosphate, for 

 instance, was applied to the leaves in the form of powder, it was found to 

 destroy them almost entirely On the other hand, it appeared that potas- 

 sium salts could be absorbed readily through the leaves of mustard plants 

 in the form of potassium sulphate, and preferably as potassium chloride 

 in the case of the soy beans. This was evidenced by the weights obtained 

 in the following pot experiments : —Without potassium the yield was 15 

 grammes; with chloride of potassium applied to the soil, 38 grammes; 

 with chloride of potassium sprayed on the foliage, 43.5 grammes; with 

 potassium sulphate applied to the soil, 45.5 grammes; and with it sprayed 

 on the foliage, 43.5 grammes. 



Proper care seems toi have been taken to insure that the salts brushed 

 or sprayed on the leaves did not reach the soil. It is, however, too early 

 to say whether these results may prove to be of practical importance in 

 agriculture, but they are to be continued, and may ultimately prove to be 

 of great value. It might, in fact, be found in some cases that spraying 

 the foliage of a crop with a dilute solution of a potassium salt might just 

 give it the required fillip at a critical stage of its existence and enable it 

 to make good a previous deficiency or to overcome a threatened attack of 

 disease. If such results can be obtained with food substances in the foriri 

 of sprays, they would of course be preferable to poisonous sy.>rays, ])ro- 

 A'ided they were equally effective. 



Professor Hiltner also gives the results of spraying Magnum Bonum 

 potatoes that were badlv attacked by Leaf Curl disease {Macrosfoiiunt 

 Solani) : — 



The above solutions were applied in 2 per cent, strengths with the 

 exception of the sulphate of iron (i per cent.), and the milk of lime (4 per 

 cent.). It can be seen that five of these .spraying materials increased to a 

 greater or lesser extent the yield of potatoes and two produced a decrease, 

 but that all of them caused some decrea.se in the percentage of starch as 

 compared with the unsprayed plot. 



It is evident that a great field for work lies open in the direction indi- 

 cated above and the further results of Professor Hiltner's researches will 

 be awaited with interest. 



