322 STATE BOARD OF AGRICULTURE 



treatment is not excessive. With the use of these materials, talking two hours a» 

 the maximum time for the treatment of the seed with formalin, the results seem 

 satisfactory, and in sections where the crop is seriously affected with the scab, the 

 use of ither of them will be found profitable. As every one of the other treatments 

 resulted in injury to the seed and partial or total loss of the crop, they cannot be 

 recommended, especially as most of them are considerably more expensive than 

 either formalin or corrosive sublimate. From the fact that corrosive sublimate is 

 a poison, many have hesitated to use it, but as it can generally be secured at any 

 drug store, Avhile formalin can be found, as a rule, only in the larger towns, the 

 former will undoubtedly be quite generally used. Corrosive sublimate caa usually 

 be obtained for eight or ten cents an ounce, and at about one-half this price in 

 larger quantities, while formalin costs about fifty cents per pound. Experiments 

 with the use of corrosive sublimate for the prevention of potato scab have now 

 been carried on for five or six years, and the method of preparing and using it has 

 several times been given, but as we have frequent inquiries regarding it, the direc- 

 tions are repeated. 



The treatment should be made in a wooden vessel of some kind, and metal re- 

 ceptacles should always be avoided. For sixteen gallons of water take one ounce 

 of corrosive sublimate, which shotild be moistened and made into a paste and dis- 

 solved in one gallon of boiling water before it is diluted. Fairly good results are 

 secured when the seed, without previous preparation, is placed in this solution and 

 allowed to remain from thirty to sixty minutes, but in case the seed is badly in- 

 fected with the scab, it is advisable to soak it in clear water for one or two liours 

 before placing it in the corrosive sublimate solution. The treatment is often given 

 after the seed has been cut, but as the exposed flesh of the tubers is slightly injured 

 by the treatment, it is advisable to soak the seed before cutting the tubers. Unless 

 to be used within a day or two. care should be taken not to allow the tubers to re- 

 main in a deep pile, and in no case should they be placed in bins, boxes or bags in 

 which potatoes have been stored, unless care is taken to disinfect these with the 

 corrosive sublimate solution. One ounce of the corrosive sublimate will be sufficient 

 for ten bushels of the seed, but as the strength of the solution is gradually reduced, 

 it is advisable to add one-half ounce of the corrosive sublimate after treating five 

 bushels and repeat this tintil all have been treated. 



The aid given by the bacteriologist. Prof. C. L. Marshall, in the way of advice 

 and assistance in making the treatments, as well as the deep interest taken by him 

 in the results, is greatly appreciated. 



Several investigators have reported marked benefits from the vtr,e of sulphur as a 

 preventive of potato scab, but our own tests do not justify this claim. As long 

 ago as 1889, when the use of this material was first advocated, we made a thorough 

 test of sulphur, using it at the rate of one hundred and fifty pounds per acre upon 

 two varieties. When the tubers were dug many of them were coated with sulphur, 

 but little if any benefit could be observed and, in one case, there were rather more 

 scabby ttibers where the sulphur had been used, than where the seed was planted 

 without treatment. As a I'esult of this experiment we have little faith in the efficacy 

 of sulphur. As compared with corrosive sublimate, the particular claim that has 

 been made for sulphur is that it is not poisonous, while a very small amount of 

 corrosive sublimate would prove fatal to animals of any kind. but. even when sul- 

 phur is used at the rate of only one hundred and fifty pounds per acre, the cost 

 would be so great that few would be likely to adopt it as a remedy, especially as 

 corrosive sublimate for treating the seed for an acre of potatoes does not cost more 

 than five cents, and if ordinary care is taken, there will be no danger from its use. 



Co-operative Ex2)eriments tvith Potatoes. 



For se'^ eral years we have sent otit a ntimber of collections of the varieties that 

 seemed most promising to thirty or forty persons in various parts of the state, in 

 order that the varieties might be tested under varying conditions of soil and climate. 

 We also aimed to thus distribute the new kinds, as the recipients were asked t 

 share their first year's crop with their neighbors. In order that the reports might 

 furnish similar data, blanks were sent with the seed on which the following points 

 were to be noted: Date of planting, date of ripening, the distance of planting, the 

 number of hills, the yield both of large and small, and the size and quality of the 

 tubers. We give below the average of the reports we have received and readers caa 

 draw their conclusions as to the varieties likely to be of value in their section. 



In order that the seed might be furnished to some of the representative farmers 



