2 ALFRED E. CAMERON. 



co-operate with the farmer in the carrying out of practical demonstrations. In my 

 opinion the adoption of similar experimental methods in this country, suitable 

 to local needs, would serve the best interests of our agricultural communities. 



In the course of my duties I had the opportunity of deriving from many farmers, 

 well versed in the most up-to-date methods of agriculture, their personal experiences 

 in the matter of spraying, and the general trend of their ideas has been hitherto 

 essentially antagonistic to the adoption of spraying with Bordeaux mixtures. In 

 the first place, they argued that the operation entailed more trouble than it was 

 thought to be worth ; and secondly, it failed to prove of any advantage when the 

 final profits came to be reckoned up. This seemed interesting in view of what was 

 the experience of others elsewhere, and I concluded that either some climatic or 

 soil factor, or perhaps some method of agriculture, counteracted or obscured the 

 otherwise admittedly beneficial effect of the insecticide, or that there was some 

 carelessness in the manner of its preparation or application. 



Three places were secured for the accomplishment of the work, namely, at Freehold, 

 Robbinsville and Elmer, in the counties of Monmouth, Mercer and Salem respectively, 

 — districts which maybe considered fairly representative of the potato-growing sections 

 of the State of New Jersey. At all three places satisfactory^ returns showed the 

 benefits to be obtained from the employment of Bordeaux mixture. At Freehold, 

 however, the increase in yield as compared w^ith the other treatments, hereafter 

 discussed, was not so marked. Indeed, so little was the difference in any of the treat- 

 ments and so uniform the yield that I am inclined to look for the reason of apparent 

 failure to the fact that peculiar methods of culture may have influenced the 

 final result. Here the surface soil is a sandy loam, containing a large amount of 

 potash (2 '5 per cent.), underlaid by a greenish yellow, sticky marl, and on this 

 particular farm a system of deep-ploughing has been adopted, enriching the top 

 soil with the most satisfactory results. In addition, the farmer is in the habit 

 of feeding his soil with abundant supplies of farmyard manure, as well as commercial 

 fertiliser, which may secure such strong and vigorous plants that the effect of the 

 Bordeaux mixture is entirely lost. In other words, what I would tentatively suggest 

 in view of the evidence obtained, is, that under certain conditions with which we 

 are not as yet entirely familiar, the potato foliage may arrive at an optimum of 

 vigour beyond which it may fail to be stimulated. At Freehold then, the slightly 

 increased yields on the home-made Bordeaux, as compared with those obtained on 

 the sulphur and proprietary Bordeaux plots, may be justly ascribed to its more 

 efficient control of the flea-beetle {Epitrix cucumeris, Harr.), which, in dry seasons 

 like that just past, levies, in New Jersey at least, a higher tax on the crop than any 

 of its vegetable parasites. Indeed, we have here a reason for the comparatively poor 

 showing of Bordeaux mixture in New Jersey. One dry season follows another with 

 such regularity that the Early {Macrosj^orium solani, E. & M.) and Late Blights 

 (PhytojMiora infesians, De Bary), which exact such a heavy toll in the more northern 

 States, here do serious damage only in an occasional wet season, when the conditions 

 are favourable to the germination of the spores. Therefore it is only natural to 

 assume that Bordeaux mixture, which is specific against these potato blights, will 

 be more likely to demonstrate its capabilities in seasons favourable to their develop- 

 ment, and this indeed has been the experience of several New Jersey farmers. 



