338 the farmers' handbook. 



Lime can usually be obtained readily in most farming centres; but if this 

 is not the case, it is advised that after draining off the Milestone solution, 

 the wheat be dipped in water. Tins washes off the excess of Milestone, and 

 while not so effective as limewater, it minimises the risk of the bluestone 

 damaging the grain. 



While the above solution of H lb. of bluestone to 10 gallons of water is 

 recommended as a general treatment, a 1 per cent, solution, i.e., 1 lb. blue- 

 stone to 10 gallons of water, is strong enough when the seed is apparently 

 clean It does less damage to the grain, and on this account is preferable 

 when limewater is not used. The stronger solution, followed by lime water, 

 however, is the more effective, and the lesser strength should only be used 

 when for any reason the limewater is not employed. 



Dry Copper Carbonate. — Recent experiments have shown that the dusting 

 of wheat prior to sowing with a powder — dry copper carbonate — gives an 

 effective control of Bunt, and does not depress the power of germination in 



the grain. 



, This method is not yet in extensive use, but may be preferred to the 

 bluestone and lime when a suitable machine for carrying out the dusting 

 has been placed on the market. 



Loose Smut Of Wheat (Usiilago tritici (Pers.), Jens.). 



Wheat affected with this smut usually has the stalks somewhat stunted. 

 The smut is produced in the ovaries, and destroys the various parts of 

 the flower (Fig. 6). The spores produced form a blackish powder, which is 

 easily blown about, and infected wheat ears are sometimes spoken of as 

 " smutty ears." The looseness of the spores sqrves at once to distinguish 

 the disease from Bunt, in which case the spores remain compacted inside 

 the wheat grains. Loose Smut has no objectionable odour. Infection takes 

 place, not through the soil, but through the flower, and when the grain is 

 formed the fungus threads lie within it and can give rise to the disease 

 again the next year in a proportion of cases, provided the gi'ain is not 

 entirely destroyed. The treatment recommended for Bunt has, therefore, 

 no appreciable effect. 



As Loose Smut requires special treatment of the seed grain for its 

 prevention the most practical way of getting rid of it after it has made its 

 appearance on a farm is to use for seed only grain which, as the result of 

 an examination of the growing crop at the proper time, is known to be 

 entirely free from this disease. To determine whether Loose Smut is pr< - 

 sent in a crop the examination should be made from flowering time onwards. 



Hot water treatment of the seed is recommended in America, but the 

 treatment is tedious and is rarely employed by the farmer, and, of course, 

 does not prevent infection of the flowers in the field by wind-borne spores. 

 The Jensen (modified) hot water treatment requires pre-soaking of the seed 

 for from five to seven hours at ordinary room temperature. The seed is then 

 put into hot water. For wheat the time of immersion is ten minutes al 

 54 degrees Cent. (129 degrees Fah.) It is important to maintain the tem- 

 perature carefully. If the temperature increases, the time of immersion 

 must be shortened, while if the temperature decreases it must be lengthened. 

 The successful margin of safety is very slight. 



