April, 1906.] Aseochyta pisi — Disease of Seed Peas. 509 



A. pisi Lib., is described as being either 1-septate or 1-celled. 

 A. Bolthauseri Sacc.,° found on the leaves of bean, is often 

 2-septate. 



Cultures. — Halsted" who was first (so far as the writer is able 

 to learn) to note and to figure the pea seed affected with Aseochyta 

 pisi, states that seed "apparently healthy when placed in the 

 ground, soon show patches and spots of a dark color, which are 

 also the spore bearing places of Aseochyta." 



Krueger^ noticed the presence of the fungus by soaking seed 

 for twenty-four hours in water, when dirty spots would appear. 

 When left for forty-eight to seventy-two hours, the mycelium 

 grew out into the water forming a white mass of radiating threads 

 similar to those of Saprolegnia. All these results of Halsted and 

 Krueger were verified. 



If one places such diseased peas in a seed germinator for sev- 

 eral days, a heavy coat of white mould will be formed about 

 them. On removing these to a covered dish where less moisture is 

 present, numerous reddish-brown pycnidia are formed all through 

 and over this white fluftV mass of mycelium. (Of course this 

 mycelium must not be confused with a similar growth of some 

 such fungus as Fusarium which often contaminates peas and 

 beans, when not kept dry, — especially just before harvesting.) 

 Peas which failed to germinate in the ground, were removed, 

 with the result, that they too, soo developed pycnidia on the 

 mycelium surrounding them. The germination of such seeds 

 is very poor. Krueger found the germination of very badly af- 

 fected seed to be 20%. In similar experiments conducted by 

 the writer the germination was only 6%. Such peas seldom reach 

 maturity when they do germinate, as the fungus affects the base 

 of the young plant. Hiltner" records the sudden dying of peas 

 from such attacks at the base of the stem. The fungus was 

 carried over to the young plants by the seed, a fact determined 

 through experiments by Jarins\ The result of these early at- 

 tacks by the fungus, is all sizes and vigor of plants. Plants of 

 equal age, range in height from two inches to four feet. In the 

 struggle between the fungus and host, the latter may not notice- 

 ably increase in size for a long period, or it may succumb at any 

 time. Young plants six inches high, affected with the fungus, 

 were planted against healthv ones of the same size, with the re- 

 sult, that the latter became diseased in a few days. Later, fruit 

 bodies formed abundantlv. 



5. Bolthauser-Anirisweil. Blattflecken der Bohne. Zeit. f. Pflanzenkr., p. 135. 



6. Halsted, Some Fungous Diseases of the Pea. N. J. Rept., pp. 357-362. 1893. 



7. Krueger, Ungewoenliches Auftreten von Aseochyta pisi Lib. on Erbsenpflanzen. 

 Centl. f. Bak. u. Par. 2, I., p, 620. 1895. 



8. Hiltner, Erbsenmuedigkeit. Sachs, landw. Zeitung., 1894, No. 18. 



9. Jarins, Aseochyta pisi bei parasitischer und saprophyter Ernahrung. Bibl. Bot., 

 Heft 34, 1896, c. tab. 



