22 MASS. EXPERIMENT STATION BULLETIN 427 



bud rot fungus, the various parasitic species of Fusarium, and the Alternaria 

 blight fungus multiply on dead carnation debris. 



In the preparation of the house for the new rooting season, all of the old sand 

 is removed and the bare benches are washed clean with water. Some cautious 

 growers drench the woodwork and ground with scalding hot water, or with a 1-75 

 solution of formaldehyde. The exposure of the bare wood to sun and drying 

 weather before resanding is also desirable. 



The presence of soil or organic matter in the sand could imply contamination 

 with the Rhizoctonia stem rot fungus which inhabits all types of soil, even virgin 

 soil. Tools should be cleaned before they are brought in contact with the sand, 

 and every effort should be made to keep soil out of the propagating beds. The 

 practice of transplanting the cuttings into soil in flats on the sand bench should 

 not be tolerated. 



Treatment of Sand 



Frequently the same sand is used for rooting more than one crop of cuttings. 

 Most growers use the sand but once and this precautionary practice is helpful 

 in avoiding trouble, but there are times in the winter months when sand is 

 difficult to obtain or to replace, and the grower is obliged to use the same sand 

 again. Peltier (53) advocated treating the sand with steam and hot water. 

 This practice would seem desirable especially for second cropping sand, to avoid 

 disease which might originate from inoculum in the sand itself. Results reported 

 by Kirby (36, 37) in Pennsylvania are strongly against the use of sand the second 

 time without first sterilizing it. In an experiment reported by him 6 to 8 percent 

 of the cuttings from new sand were infected with Alternaria in contrast to 56 

 percent from second-crop sand. The harvest of health}- well-rooted cuttings, 

 rooting above 90 percent, should indicate that the same sand is safe for further 

 planting. Nevertheless, commercial practice recognizes that rooting and disease 

 control are improved by the use of new sand. 



Some growers drench the sand with 1-1,000 solution of potassium permanganate 

 previous to second use, and the practice is based chiefly on the faith in the chemi- 

 cal that some growers have acquired from its use as a disinfectant for cuttings. 

 The results have been questionable in the absence of sufficient evidence and since 

 the chemical is considered only mildly fungicidal. The results of a test with 

 Virginia cuttings on new sand in March in a grower's propagating house where 

 serious losses of cuttings from Fusarium culmoriim, the root rot fungus, were 

 occurring maj'^ be considered rather typical. 



Percent Well Rooted 

 Treatment (Based on 140) 



Potassium Permanganate 



(Cuttings) 96.5 



(Sand) - . 95.3 



(Cuttings and sand) 92.6 



No Treatment 86.7 



The results appeared to show that factors in the grower's practice, not revealed 

 in this test, contributed to his loss. The value of propagating clean cuttings from 

 clean sources was recognized and a greater improvement in the stand would 

 appear to result from treating the cuttings rather than the sand with potassium 

 permanganate. Potassium permanganate is not comparable in its fungicidal 

 effect with the more generally recognized fungicidal chemicals, but it has a 

 unique stimulating effect on rooting and is tolerated, which makes its use es- 



