DISEASES AND ENEMIES OF WHEAT. 329 



gust, when the weather is damp and warm. The wheat is 

 thus forced to such a rapid growth that the vessels are burst, 

 and the sap exudes and causes the rust. In either case there 

 is no known remedy. 



2. Mildew or blight gives to the plant a purple or bluish 

 cast, resembling the mould on damp walls ; and is supposed 

 to be due to a species of parasitic plant, a fungus which 

 attaches itself to the stalk. This happens during warm, wet 

 weather, or heavy dews. The only remedy is to brush off the 

 water in the morning by dredging the field with a rope. 



3. Smut is of two kinds. The first kind is seen in the heads, 

 about the time of the ripening of the grain ; the heads soon dis- 

 appear, leaving nothing but the naked stalks. The second kind 

 appears in the form of a black dust, which soon spreads itself 

 over the field. The grain is not destroyed, but the flour is 

 rendered black and poor. This is also supposed to be a spe- 

 cies of fungus, as it can be propagated through a field. This 

 disease may be prevented by soaking the seed in strong brine 

 or stale urine, sprinkling it while wet with slacked lime, and 

 leaving it for twenty-four hours before sowing. 



The enemies of wheat are the wire-worm, Hessian fly and 

 grain insect. 



1. Wire-worm. This worm is well known to farmers, and 

 its ravages are mostly confined to the sward. This effect 

 may be remedied by ploughing in the fall, so that the frosts 

 of winter may destroy the worm. 



2. The Hessian fly is found as a maggot between the leaf 

 and the culm, in the first joint of the plant, and, by bedding 

 itself in the stalk, destroys it. No certain remedy, for the 

 ravages of this insect, has as yet been found. Late sowing 

 will sometimes carry the crop beyond the fly-season. 



4. The grain insect appears in the form of a fly, hovering; 

 over the field about the time the grain is in blossom. It de^ 

 posits its eggs, from which a yellow maggot is hatched, and 

 appears in the head after it has destroyed the grain. A 



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