20 MASS. EXPERIMENT STATION BULLETIN 428 



fir and Sawara cypress with Arasan or Fermate; Abies nephrolepis Maxim, with 

 Arasan, Fermate, or Spergon. 



November cuttings of Norway spruce and Korean fir rooted in larger percent- 

 ages in sand watered from above than in sand subirrigated; that is, watered only 

 from below. 



Rooting of November cuttings of Norway spruce was decidedly improved by 

 treatment with manganous sulfate 0.5 or 1.0 percent solution for 22 hours. Root- 

 ing of cuttings of Chinese juniper was much more improved by treatment with 

 potassium nitrate 500 mg./l., 18 hr., preceding treatment with Hormodin No. 3 

 than it was by Hormodin No. 3 used alone. 



Rooting of cuttings of black spruce and of 3 varieties of Norway spruce was 

 improved or hastened by treatments with monobasic potassium phosphate 0.25 

 or 0.5 percent solution, 21 hours; and in the two cases where comparisons were 

 made, indolebutyric acid was less effective. 



Cuttings of Colorado fir and Juniperus squamata Lamb, rooted less well if 

 allowed to lose 10 percent of their fresh weight before treatment. 



Beach plum cuttings rooted well in 4 weeks after solution-immersion treat- 

 ment with indolebutyric acid even though they were taken as late in the season 

 as the last of June. For these cuttings taken relatively late, powder-dip treat- 

 ments were less effective. 



November cuttings of a hemlock treated with Hormodin No. 3 rooted 92 per- 

 cent if from the north side of the tree, 25 percent if from the south side. Novem- 

 ber cuttings of a Norway spruce treated with manganous sulfate (1.0 percent 

 solution, 19 hr.) rooted 50 percent if from the north side of the tree, 8 percent if 

 from the south. December cuttings of arbor-vitae finally rooted 100 percent 

 in any case, but those from the south side of the tree required 50 to 75 percent 

 more days for rooting. Out of 31 possible comparisons with white pine cuttings 

 taken in March from 3 different trees, cuttings from the north side of the trees 

 rooted best in 17 cases, those from the south side in 7 cases, and there were no 

 differences in 7 others. 



Treatments of November cuttings of arbor-vitae (with indolebutyric and indole- 

 propionic acids) which were apparently injurious in sand-sphagnum peat were 

 not injurious in sand-sedge peat. November cuttings of Norway spruce rooted 

 better in sand-sedge peat than in sand-sphagnum peat. 



Diseases of Plants Caused by Soil-infesting Organisms, with Particular Atten- 

 tion to Control Measures. (VV. L. Doran.) The effects of certain soil treatments 

 on club-root of cabbage (caused by Plasmodiophora brassicae Wor.) were in- 

 vestigated. The disease was not prevented by ammonium sulfate (and lime), 

 calcium cyanamide, or Fermate as used, but it was fairly well controlled by 

 mercurous chloride 0.2 or 0.15 gm. per square foot without injury to growth of 

 plants. Mercuric chloride similarly used retarded their growth. Sodium chloride 

 used alone did not control club-root but 10.0 gm. per square foot appeared to be 

 favorable to growth of plants and mercurous chloride gave rather better control 

 when used with sodium chloride than when used without it. The percentages of 

 infected plants were: 



Soil Treatment Percentage of 



Infected Plants 



No treatment - - 95 



Mercurous chloride 0.15 gram — H 



Mercurous chloride 0.15 gram plus sodium chloride 10 grams 13 



Mercurous chloride 0.2 gram 20 



Mercurous chloride 0.2 gram plus sodium chloride 15 grams 



