NEMATODE GALLS IN MARKET WHEAT. 



Farmers and mill operators who were questioned about this disease 

 stated that it had been known to them for varying periods of from 

 5 to 20 years. They had known it under such names as hard smut, 

 cockle, bin-burned wheat, frosted kernels, and immature wheat. As 

 a matter of fact these galls are quite different. In figure 7, where 

 they are pictured in contrast, they can be easily distinguished from 

 bin-burned wheat, frosted wheat, smut, and corn cockle. 



Smut can be distinguished readily from these galls by crushing under 

 the thumb. Smut balls can be crushed in the hand and leave the hand 

 covered with a mass of black, evil-smelling material. It is almost im- 

 possible to crush nematode galls on account of their hardness. Some 



Fig 



-A portion of the inside of the gall magnified to show the coiled 



nematodes. 



conditions of smut, i. e., hard smut, may be mistaken for these galls, 

 but if cut open will at once show the absence of the inner yellowish- 

 white portion, which is a distinguishing feature of the nematode galls. 

 Cockle is easy to distinguish because of the spiny appearance of 

 its seed coat. Bin-burned wheat frequently has been confused with 

 these galls. It may be distinguished from nematode galls, however, 

 because the shape of the bin-burned wheat kernel remains intact in 

 spite of the decoloration. This is not true of nematode galls, which 

 are very irregular in shape. The powdery substance present within 

 the gall is not found in bin-burned wheat. 



