DISEASES OF PLANTS. 1189 



lifter the seed was sown, the fuii^icklo was sprhikled or scattered over it and 

 the adjacent earth before coveriiifj. The fertilizer was scattered directly over 

 the rows after the seed was covei'ed. At the time of tlie harvest the yield of 

 the different plats was as follows: Check plat 121 Im. jicr acre, formalin treat- 

 ment 207), limoid 202. sulphur and limoid 101. and complete fertilizer 15. 

 Another series of experiments was condiictod in which similar treatments were 

 Kiven plats of onions after the disease had made its ai)i)earance, but in no case 

 was an.v apprecial)le benefit found that could be attrilnited to the use of the 

 remedy. While these yields are not equal to the average during a favorable 

 season, yet for tlie treated plats they were greater than the average yield in the 

 best iintreated. iniinfected areas. 



A study was made of the dry rot fungus (Mcrulius Uicri/inaiis), tlie author's 

 attention having been called to its rapid spread in the timber of a building. 

 The nature of the injury, character of the growth, and damage cau.sed are 

 (l(>scribed. after which the pi-eventive measures which were suggested are out- 

 lined. These consisted in the removal of the infected woodwork, provision for 

 drainage in order that the walls of the building should not become damp, and 

 sitraying the portions of the building where the wainscoting had l)een removed 

 with formalin and carbolic acid. 



Particular attention during the past season was given to the root rot of tobacco 

 (Thiclavia basicola). This disease has become a serious pest in certain fields 

 in Connecticut, and while probably not new, has only recently attracted the 

 attention of tobacco growers. The history of the fungus, its nature, distribu- 

 tion, etc., are given at some length, after which an account is presented of the 

 investigations carried on in Connecticut. In some respects the fungus resembles 

 the damping off in the seed bed, but it is (|uite distinct from it in that the root 

 rot develops almost entirely under ground, attacking the roots and underground 

 portions of the stems. The grower first notices the presence of the disease by 

 bis plants failing to make normal growth and their unhealthy, dark-green color. 

 \n examination was made of fields and seed beds in a ninnlier of localities 

 tln-ougliout the State, which resulted in the discover.v that the fungus is widely 

 distributed. Experiments were conducted both in the seed beds and in the 

 fields for the control of this trouble, and following the recommendations of 

 A. D. Shamel of this Department, who is cooperating with the station in tobacco 

 investigations, sprinkling the seed beds with a solution of formaldehyde. 1 to 

 2.000 of water, was tested without much effect. The sterilization of the soil, 

 either b.v the use of stronger solutions of formaldeh.vde or by steam, it is believed 

 would he an efficient method of combating this disease in the seed bed. In the 

 fields the exi)eriments were carried on to test the effect of transplanting diseased 

 plants, the effect of transplanting healthy plants into infected soil, and the 

 effect of environment on tlie development of the disease. There apjiears from 

 the results of the experiments to be no reason why the best plants from infected 

 Iteds may not be safely transplanted to the fields, but those which have been to 

 an.v extent attacked by the fungus should !iot be transplanted. The setting of 

 healthy plants in infected soil showed that the disease was readil.y transmitted 

 from the soil to them, and it was found that the character of the soil, subsoil, 

 season, drainage, humus, and the kind of fertilizer, all have much to do with 

 determining the amount of injiu'v (auscd by the fiuigus. P>ased upon the 

 investigations of the one season, the author suggests various measures for 

 preventing the spread of the fungus and injur.v due ti) it. 



The report concludes with a list of references to the literature relating to this 

 root rot. 



Alfalfa root rot, J. J. Tiiokxhkk (Arizona Sta. Rpl: 1006. pp. lHO-162^. — \\- 

 falfa throughout southern Arizona is said to be subject to a root rot which is 



