lo Sept., 1910] 



Scab " and Eel-worm in Potatoes. 



575 



Taking the average of the three plots, the very slight decrease in the 

 case of the strong potash manure over the normal potash is not sufficient 

 to prove a harmful effect, just as in the case of the superphosphates the 

 small increase for the use of extra acid manure is not suthcient to prove 

 a beneficial effect. 



No matter how closely the figures for these manured plots are scrutinized 

 the fact remains that the plots turned out a clean sample in every case. 

 The rejected potatoes were comparatively lightly scabbed, except in the 

 case of iron sulphate, and the marketable tubers were of much finer quality 

 than those from unmanured portions. It may be contended that this was 

 due to the use of clean formalin-treated seed, but that some of the manures 

 plaved an important part in producing cleanness, is seen by a study of 

 the" figures in the last column of the table. It will be readily seen that 

 between the lowest average in the three plots and the highest, there is a 

 difference of 13 per cent., and this can only be put down to the value of 

 one manure over the other, or if we leave iron sulphate out as not being a 

 true manure, a difference of 9 per cent, between nitro-superphosphate and 

 superphosphate must be accounted for in the same way. 



It is a convincing fact that where clean seed, formalin treatment and 

 artificial manuring were resorted to, by far the best results were obtained, 

 and it is reasonable to expect that a much smaller dressing of manure 

 would have the same good effect as the larger quantity. 



Increased Yields from the use of Manures. — Although the plots were 

 not put in primarily for the purpose of testing the yielding capacity of 

 the manures, still some useful information was gained on this point by 

 weighing the produce of each row and comparing the results. 



The following table demonstrates the relative value of different manures 

 and also their value over no manure on five different farms : — 



A glance at the table shows that the double potash potato manure 

 gave the best results, returning an average of 5 tons 8^ cwts. per acre, 

 while it also had the highest aggregate yield of 8 tons 8 cwts. at Mr, 

 Crowe's farm. Its extra yield over potato manure A does not, however, 

 compensate for its extra cost, as it is quoted at £■; los., whereas potato 

 manure A mav be obtained for ^6 los. per ton. 



The cheapest manure would appear to be the ordinary superphosphate. 

 It gave verv creditable vields, returning an average of 5 tons 4 cwts. per 

 acre on five farms, and it has the additional advantage of being much 

 cheaper than the potash or nitrogenous manures, as it is quoted at £4. 7s. 

 6d. per ton. 



Experimental Plots for Eel-worm. 



As Eel-worm is prevalent in the Warrnambool and Gippsland districts, 

 plots of \ acre each were obtained at Koroit and Drouin respectively for 



