lo Sept., 19 io] " Scab '' and Eel-worm iti Potatoes. 



571 



Note. — The percentages recorded throughout this report were obtained from the weighed produce of 

 the row or set of rows as the case may be. 



Taking the corresponding two plots at Mr. Shearer's farm, the one 

 sown with untreated scabby seed returned 56.7 per cent, clean produce, 

 whilst the other which was sown with formalin-treated seed, returned 

 76.5 per cent, clean potatoes, a clear gain of 19.8 per cent., or 4 cwt. 

 of clean potatoes in each ton of produce. The cost of the formalin is 

 trifling — is. 6d. per lb., and as i lb. is sufficient to treat seed for about 

 two acres, the return for the outlay is immediately seen. 



At Mr. Summers' farm, Lancefield, Carman seed was sown in the two 

 corresponding plots, but at the time of digging, the results from the treated 

 and untreated plots were about the same. The Scab in this district, how- 

 ever, does not resemble the "pitted " appearance of the Ballarat disease, 

 but resembles more a " scab " caused by the bursting of blister. If it is 

 caused by Eel-worm it is not, as Mr. Crowe's plot at Koroit shows, amen- 

 able to formalin treatment. 



To test whether any good results were obtainable by the use of for- 

 malin where clean seed was employed, two more plots were sown, one 

 with clean seed which was soaked in the formalin solution for two hours, 

 the other with clean seed that was not treated. At Mr. Shearer's farm 

 the results were about equal for both plots, but at Mr. Downey's farm, 

 the untreated seed returned 59.5 per cent, of clean tubers, where the 

 treated seed returned 74 per cent, clean potatoes, or a gain of 14.5 per 

 cent, by treatment. Mr. Summers' plots, on the other hand, showed a slight 

 decline in the formalin-treated seed, and taking his plots right through, the 

 form of Scab occurring on this farm seems to offer little, if any, response 

 to formalin, and, as stated before, is probably not due to a fungus 

 disease. 



Use of Chan as against Scabb v Seed. — During the course of the 

 experiments, it w'as often stated by the farmers that they could grow just 

 as clean a crop from scabby as from clean seed. Some useful light is 

 thrown on this point by these experiments, which certainly do not lend 

 much strength to this argument. By comparing plot i, which was sown 

 with scabby untreated seed, with plot 3, which received clean untreateu 

 seed, the difference in favour of using clean seed is evident. 



