Through culturing one can establish stock that is free from fusarium wilt and bacterial wilt. Every precaution must be taken, however, to prevent reinoculation. Stock plants therefore should be isolated from other carnations. One person should be responsible for them. The method will be successful only if the plants are grown the year around in the greenhouse. If all steps are followed carefully, a clean mother block of plants can be built up in a short time. Once a mother block is established it should not be necessary to culture cuttings every year, if rigid sanitation and proper cultural practices are maintained.

D. Noordam, T. H. Thung, and J. P. H. Van Der Want in the Netherlands have developed an antiserum for carnation mosaic. The reaction of the serum with sap from diseased carnations indicates the presence of virus and may be used as a method of screening diseased plants before symptoms are evident.

CARNATION CUTTINGS may carry infection from the mother stock internally as localized spotted or rotted tissue, as systemic and hidden infection, or as inoculum of the fungus in the form of spores existing superficially on the cuttings. Consequently it generally is unwise to soak cuttings in water to freshen them because of the risk of contaminating the water and inoculating the entire lot.

Cuttings may be planted promptly and directly without trimming or wetting them, and they should root well. Good drainage in the cutting bed, shallow planting hardly in excess of 1 inch in the rooting medium, proper temperature and light conditions, and sanitation require attention.

Sometimes the medication of cuttings before planting to kill surface-borne inoculum of pathogenic fungi is useful. Dousing cuttings for an instant in ferbam or zineb, 1 ounce to 4 gallons of water, is recommended for controlling rust and alternaria spot. A light powdering of the base of the cutting with a 10-percent fungicide-hormone dust mixture helps to prevent infection at the base of the cutting. The phenyl mercury fungicides have a disinfesting action, and the immersion of untrimmed cuttings for 15 minutes in phenyl mercury acetate solution, one-fourth teaspoonful to 1 gallon of water, is effective. After immersion, the base of the treated cuttings is snapped off to the next node and then planted; otherwise, the cuttings will not root well. The addition of a wetting agent to the medicant is recommended (Dreft, three-fourths to 1 level teaspoonful to 1 gallon of water).

Cuttings are freely distributed in the trade without restriction, and all the diseases in the mother stock may be transmitted with cuttings. The word and reputation of the propagator is the only assurance of the quality and health of the stock. Among other crops propagated vegetatively, such as potatoes and nursery stock, standards of certification for freedom from disease and regulations governing certification are recognized.

The carnation industry has been interested in the possibilities of cultured cuttings for eliminating infection and developing healthy mother stock actually an effective standard of certification. The conventional method of propagating can be supplemented with these further efforts to guarantee the distribution of clean stock. Some form of certification would appear to be desirable in the industry.

THE GROWING of commercially desirable carnations resistant to disease is a logical and practical method of controlling disease. Research workers, however, have not given it enough consideration. With the exception of stem rot, caused by the fungus Corticium (Rhizoctonia) solani, and canker, dieback, and crown and root rot, caused by the fungi Fusarium culmorum and F. avenaceum, resistance and susceptibility to every carnation disease have always existed among varieties in the long history of commercial carnation culture.

Disease-resistant varieties offer the breeder valuable parent stock for breeding purposes. These evident and distinct contrasts in the reaction of standard varieties to disease in commercial culture can be established scientifically and confirmed for each pathogen by artificial infection techniques a necessary preliminary step, we think, to the actual breeding program. In this work, selfing and hybridizing should be confined to parent varieties consistently resistant to one pathogen or more than one pathogen. By that procedure, the high degree of resistance peculiar to both parents will appear in most of the seedlings of the first generation. These resistant progenies can be used for further breeding selfing, backcrossing, and out-crossing.

The successes in breeding crop plants for disease resistance and horticultural desirability are numerous. Examples of the effort in behalf of the carnation industry are the varieties Mrs. E. F. Guba, Waltham Pink, Spicy Rose, and others resistant to fusarium wilt. A breeding program for disease resistance with broader application has been started in the Department of Agriculture.

EMIL F. GUBA, a native of Massachusetts and a graduate of the University of Massachusetts and the University of Illinois, has been on the staff of the Waltham Field Station, University of Massachusetts, since 1925, specializing in carnation diseases, mycology, and general plant pathology.

RALPH W. AMES, a native of Wyoming, holds degrees from the University of Wyoming and the University of Illinois. He has been identified especially with the study of carnation virus diseases and florist crop diseases. He was formerly on the staff of the Waltham Field Station, University of Massachusetts. He now teaches plant pathology in Utah Agricultural College.