12 ALFRED E. CAMERON. 



It is of interest to note the general uniformity of the figures, there being very 

 little variation in yield in the plots of each individual series, except perhaps in series I 

 where the Bordeaux plot outyielded the average of the control plots by 18 bushels 

 per acre. In this series too the sulphur-gypsum-lead arsenate plot also gave an 

 increase of twelve bushels per acre over the control plots, while the plot sprayed 

 with Ansbacher's Bordeaux and lead arsenate lagged behind the control plots to 

 the extent of 14*5 bushels. But this only serves to show how little confidence can 

 be placed in results when the figures of only a single series are considered. The 

 truth can only be ascertained by averaging up a number of series. 



The field at Freehold, as regards previous cultivation, presented three distinct 

 sections. Six acres had been planted in potatoes for four years, and each year 

 wheat and crimson clover had been ploughed under as a green manure. Nine acres 

 had been planted with maize during the two previous years and cow-peas sown out 

 amongst the maize. Here there had been a rotation of wheat, clover and timothy, 

 and maize. The remaining nine acres had borne a potato crop continuously for 

 six or seven years, and on this particular section a system of deep ploughing had 

 been practised. It has already been mentioned how radical cultivation of this type 

 might obscure the effects of spraying. 



At Robhinsville. On the whole the weather was very dry in this district of the 

 State during the summer, but frequent showers helped to bring the rainfall up to 

 about ten inches, extending over a period of about three months from 27th May, 

 when spraying started, until the potatoes were dug. Shortly after the first treatment 

 was made there were neither many flea-beetles nor Colorado beetles to be seen, 

 although the infestation was quite severe on other fields planted with early " Cobbler " 

 seed. The variety here treated was the " Green Mountain." 



There were four series of plots, all approximately of the same size, except those 

 of Series IV, which were less than half the area of the others. The general contour 

 of the field was rather irregular, but this did not affect the results at all. Throughout 

 the growing period, the foliage on the Bordeaux plots was easily superior to the 

 foliage on the other plots, except in the first series, where, for some inexplicable reason, 

 there was quite a lot of "tip-burn "in the Bordeaux plot, especially about 30th June. 

 Early and late blights were conspicuous by their absence, while only a few hills were 

 affected by dry rot (Fusarium oxysporum). Examination of the field on 16th August 

 revealed the plants on the Bordeaux plots still green and quite vigorous, while on 

 other plots they were quite dead. The potatoes were dug on 1st September and 

 the following days, and an observer, casting his eye over the field, could with a little 

 discrimination pick out the plots treated with Bordeaux mixture, by reason of their 

 being less over-grown with weeds. This in itself would point to the invigorating 

 effect of the mixture. The potato plants become so sturdy by reason of its application 

 that they suffer less from competition with inimical weeds, especially crab-grass. 



The very low yield on the Bordeaux plot of the first series might cause surprise. 

 Indeed, no other plot in this block did so poorly, except one of the control plots where 

 the yield was practically the same. Had it not been for the adverse conditions 

 obtaining on this plot, the average yield in the Bordeaux plots as a whole would 

 have been at least 20 bushels per acre more. Similarly, the adverse conditions 

 which prevailed on the sulphur plot of Series IV helped to reduce the average yield 



