94 AMERICAN HUSBANDRY. 



spring by its effects on fruit. Blight originating in 

 heat and vapour generally occurs in the summer, 

 when plants have attained their full growth, and 

 when there is no cold weather or wind to produce it. 

 Blight from want of nourishment is found in grain 

 on thin, poor soils, where the plants have been pre- 

 maturely forced into blossom, and the ear ripens or 

 dries before it is filled. Blight from fungus propa- 

 gations is the most common and the most injurious 

 to grain. It generally assumes the appearance of a 

 rusty-looking powder, soiling the fingers or clothes 

 when touched ; and when in sufficient quantity se- 

 riously to injure the crop of grain, it gradually 

 passes into dark patches or lines on the stalk or 

 leaves, eftectually preventing any farther ripening of 

 the straw or grain until dried by cutting and curing. 

 Fields of wheat are injured by rust or blight in the 

 most irregular and capricious manner ; and there is 

 reason to suppose that the cause or causes are not 

 yet perfectly understood. One of the most plausible 

 conjectures, perhaps, is that of Grisenthwaite in his 

 New Theory of Agriculture, viz., that in many cases 

 in which blight attacks grain, it may be for want of 

 the peculiar food requisite for perfecting the grain — 

 it being known that the seeds of plants contain prim- 

 itive principles not found in the rest of the plant. 

 Thus the grain of wheat contains gluten and phos- 

 phate of lime ; and, where these are wanting in the 

 soil (that is, in the manured earth in which tlie plant 

 grows), it will be unable to perfect its fruit, which, 

 of course, becomes more liable to disease. The fun- 

 gus or rust of wheat is called the Uredo linearis; and 

 as a fungus something similar in appearance is found 

 on the common barberry bush, Berberis vuJ^aris, it is 

 a general opinion among farmers that this busb is th« 

 cause of blight in the grain-fields of this vjcinitv * 

 '■*.iis would seem to be entirely an error, as anfiJi'9' 



* Albany. 



