366 



Bunt and Smut. 



for two minutes in water at 1 1 5 0 and fifteen minutes at 

 132 0 F. ; steeped for one hour in i oz. of a 40 per cent, solu- 

 tion of formalin to 1 gallon of water ; (f) steeped for one hour 

 in 1 lb. of crude carbolic acid to 1 gallon of water ; and (g) 

 steeped for six hours in \ oz. pure caustic soda to 1 gallon of 

 water. The first of these solutions, viz., the sulphate of copper, 

 was found to be most satisfactory. The mixture of copper sul- 

 phate and quicklime, the hot water treatment, and the urine got 

 rid of the bunt ; but the quality of the grain was only fair, and 

 in the case of the urine shrivelled. Neither caustic soda 

 nor carbolic acid produced favourable results. 



The Wisconsin Agricultural Experiment Station has published 

 a report* of an investigation regarding the prevention of smut 

 in oats by means of the submersion of the seed in a solution of 

 formaldehyde. The disease is reported to have rapidly increased 

 in that State, though the farmers there do not generally seem 

 to be aware of its presence, as the smutted heads grow on 

 weakly stalks, and generally head lower than the fully developed 

 plants, so that they escape notice. The treatment recommended 

 consists in steeping the seed in a solution of formaldehyde, and 

 experiments were carried out to determine the most suitable 

 strength of the solution. Seeds were accordingly soaked in 1 lb. 

 of a 40 per cent, solution of formaldehyde to 50, 100, and 

 200 gallons of water, for periods varying from ten to sixty 

 minutes. It was found that in order to be entirely effective 

 oats should be submerged for twenty minutes in a solution 

 made at the rate of r ib. of formaldehyde to 50 gallons of water. 

 This o;ives the solution sufficient time to soften the outside 

 covering of the oats, and to penetrate and kill the smut germs 

 within the hull. A weak solution or a short period of sub- 

 mersion had only a partial effect, and when the treatment is 

 not entirely effective a few smutted heads will inoculate the 

 perfect ones, so that in two or three years the oats may be as 

 bad as ever. Once the oats have been treated effectively and 

 a little care is taken to prevent further contamination, it is 

 said that several years may elapse before further treatment is 

 necessary. 



* 1 8th Annual Report, 1900 — 1901, p. 255. 



