PLATE 49 



A. — Basal portions of lo representative Chevalier barley plants, from tintreated 

 and treated seed, selected from the lots illustrated in Plate 48. The 5 plants at left 

 are from those shown in Plate 48, A, from untreated seed. Note the marked Hel- 

 minihosporium sativum leaf lesions, basal browning, kernel discoloration, and root 

 rotting. The 5 plants at right are from those shown in Plate 48, B, from the treated 

 seed. Note the freedom from disease. Tliere is no evidence of leaf lesions, basal 

 browning, kernel discoloration, or root rotting; roots are clean and bright. All plants 

 from seed treated by the dry-heat treatment were a trifle slower in germinating, but 

 in the second leaf stage they had overtaken or surpassed those from untreated seed. 

 This sturdier growth is evident in the illustration. 



B. — Representative Kubanka wheat seedlings from untreated seed (6 plants at left) 

 and treated seed (5 plants at right) referred to on pp. 385-386. The 6 plants at the left 

 show characteristic seedling injury from wheatscab organisms. All 6 of these plants 

 had discolored kernels, rotted bases, and rotted proximal portions of roots. They 

 were also much weaker than those from the treated seed. The first 2 plants on the 

 left were killed after they reached the surface of the ground; the third plant was 

 killed before reaching the surface of the ground. Typical Gibberella perithecia devel- 

 oped on this dead plant under the soil and at the surface. The 5 plants at the right 

 represent the disease-free condition of plants from treated seed from the same seed 

 lot. This seed had been exposed to dry heat at about 100° C. for 30 hours. The plants 

 are free from any evidence of disease, the bases, kernels, and roots all being clean. 

 Plants from treated seed are also much sturdier than those from imtreated seed. 



Approximately one-half natural size. 



