334 Pomona College Journal op Economic Botany. 



March 4th — Inoculation of mature, sound potatoes. These potatoes 

 were prepared by being tliorouglily scrubbed in tap water, washed in a four 

 per cent solution of formalin, rin.sed several times in distilled water, placed 

 in sterile glass chambers and kept one week before being inoculated. Three 

 chambers were prepared in this way and inoculated with strains (R), (VII), 

 and (H) respectively, by means of an incision in the potato. The pota- 

 toes were examined April 20th. The fungus grew in each instance, but none 

 of the strains were able to penetrate the potato any apprecial)l»' distance. 



REMEDIAL MEASURES 



The field observations have shown tliat the carnation stem-rot disease 

 is not serious, probably not more than one-half of one per cent, or one 

 per cent loss occurs from it; yet almost every grower who has been grow- 

 ing carnations for ten or fifteen years remembers a time when the di.sea.se 

 was of a serious nature. A rea-son for the lesser activity of the disease 

 has not been determined, but it is probable that more resistant varieties 

 are now grown and that the methods of culture have been improved. At 

 present the control of the disease can almcst entirely be obtained by observ- 

 ing the most improved cultural methods. Many of the suggestions given 

 here are those practiced by the most intelligent growers in this vicinity. 

 They are simple and do not involve any extra expense in their application. 

 Always select vigorous cuttings from thrifty, healthy plants. Use a sharp 

 knife in preparing the cutting, in order to secure clean cuts; carefully 

 remove all leaves from that portion of the cutting, which, when planted, 

 comes in contact with the soil. Do not use the same .soil more than one 

 season. A change of soil is not only a preventive measure against di.sease, 

 but favors the growth of a more vigorous and productive plant. Avoid, as 

 far as possible, sudden changes in temperatures and moisture, particularly 

 high temperatures and extreme dampness. Provide for a free circulation 

 of air about the plants. When transplanting, be careful not to injure the 

 plants and do not set them too deep, i. e., do not allow any part of the 

 .stem to come in contact with the soil which was not formerly in contact 

 ^\^th it. Irrigate the beds in the morning, in order that the leaves of the 

 plants and the surface soil may become dry before night. When infected 

 plants are observed, remove them from the beds and destroy them. Grow 

 the varieties which experience in a given locality or soil has shown to 

 be the most resistant, provided such varieties meet the demands of the 

 market. The disease is not serious enough to warrant the selection of a 

 variety which is not of the best market type. The grower who observes 

 these simple but essential rules in culture need not fear any serious trouble 

 with the stem-rot disease. 



