1140 EXPERIMENT STATION EECOED. 



due to attacks of an niKlergroiind funsiis cansiiis the plants to die out in well- 

 defined, usually circular areas or spots. Uiwn examination the tap roots are 

 found to be diseased and commonly in a well-advanced stage of decay, so that 

 with a little effort they may be pulled from the ground to a depth of 12 to 20 

 in. The attack of the fungus upon the roots usually stops a little below the 

 surface of the ground, leaving attached to the crowns one or more uninjured 

 root stubs. During hot, dry periods, such as occur in that region, the plants 

 quickly die from inability to absorb moisture. 



The first sign of disease on the plants is characterized by the yellowing or 

 wilting, and upon careful examination there will be found distributed over 

 the surface of the roots numerous sterile filaments which freciuently form 

 masses of dark-bi'own mycelium. The fruiting or spore-bearing stage of the 

 fungus is said to develop discontinuously ujion the ground along the outer mar- 

 gin of the zone of dying plants and immediately above the matted mycelium. 

 The spore-bearing portions are described as flattened, cushion-like, filamentous 

 masses, 2 to 10 in. or more in extent and i in. in thickness. During the 

 younger stages this mass is a creamy-white color, but in age becomes yellowish- 

 brown and breaks up into a fine, powdery spore mass. The sterile mycelium 

 is technically described and measurements are given for the spores. It appears 

 that the spores retain their power of germination for at least a year. So far 

 as this publication is concerned, the fungus has not been definitely identified. 

 It is believed that resistant strains of alfalfa may be obtained to use in seeding 

 infected areas. 



Potato scab, W. J. Morse (Elaine Sta. Bui. l.'fl, pp. 8i-92 ).^Accoi-ding to 

 the author, the amount of potato scab is rapidly increasing in various portions 

 of Maine, and the object of the bulletin is to warn growers of the gravity of 

 the situation, and to suggest methods for control of the disease. After describ- 

 ing the cause of the scab,, the conditions favorable for its development, and the 

 management of infested soils, the author describes the formaldehyde treatment 

 both in the form of gas and as a disinfecting solution for the prevention of 

 the scab. For large (juantities of seed he reconmiends the use of formaldehyde 

 gas generated by the use of potassium permanganate as the most practical 

 disinfecting agent. 



The effects of some fungicides recommended for the prevention of stink- 

 ing smut on the germination of wheat, G. L. Sutton and J. T. I'ridham 

 (Agr. Gas. N. 8. Males. J8 (1907). Xo. 3. pp. 235-253, fiffs. 10).— The authors 

 carried on a series of experiments in plats, boxes, etc., to determine the effects 

 of fungicides on the germination of wheat under various conditions of experi- 

 mentation. 



In the first series IS varieties of wheat were treated with hot water, formalin, 

 copper suli)hate, copper sulphate solution and slaked lime, and copper sulphate 

 solution and lime water to determine whether the treatment would h;ive an 

 injurious effect on seed grain. Fi-om the tabular statements i»resented it is 

 seen that the germination was retarded to some extent by the different treat- 

 ments in the following order, beginning with the treatment which retarded the 

 germination least: Formalin, copper sulphate and slaked lime, copper sulphate 

 and lime water, hot water, and copper sulphate. The ameliorating effect of 

 lime used after the copper-sulphate treatment is clearly indicated by this ex- 

 periment, and the authors recommend its use either in the form of slaked lime 

 or lime water whenever seed is treated with copper sulphate. 



A second series of experiments was conducted to ascertain whether it is 

 advisable to treat the seed just prior to planting or whether it may be done 

 with safety some time before planting. These exjieriments were divided into 

 two parts. In one tlie seed was spread in the sun and dried immediately after 



