ANNUAL REPORT, 1945-46 45 



Treatment of Sand with Fermate for Carnation Cuttings. (Harold E. White, 

 Wahhani.) Propagating sand for use in rooting carnation cuttings was treated 

 with dry Fermate (ferric diniethyldithiocarbamate) at the rate of 2 pounds and 

 3 pounds per 100 square feet. Cuttings from 12 varieties of carnations were 

 placed in treated and untreated sand. The increase in percentage of rooting of 

 carnation cuttings in Fermate-treated sand over untreated sand was quite vari- 

 able. Eleven lots of cuttings showed increases in percentage of cuttings rooted, 

 from as low as 1 percent to as high as 25, and six lots showed a decrease in com- 

 parison with untreated. The difference in percentage of cuttings rooted in the 

 2-pound and 3-pound treatments was equally variable. Rooting response to the 

 same treatment varied with varieties of cuttings. When cuttings of a particular 

 variety rooted poorly with no treatment, the response was poor with the Fermate 

 treatment. 



The results obtained in these tests indicate that Fermate applied directly to 

 the sand is of no particular value for rooting of carnation cuttings. Losses from 

 rot diseases in the cuttings were not sufficient to determine whether such treat- 

 ments are effective as a means of disease control. 



Sodium Selenate as a Red Spider Control. (Harold E. White, Waltham.) 

 In tests at Waltham, the application of sodium selenate to soils in which carna- 

 tions are growing has proved to be an effective means of controlling red spider. 

 Experiments were conducted on plants grown in pots, flats, and benches. Ob- 

 servations were also made on plantings of treated carnations in local greenhouse 

 ranges. Young carnation plants in flats remained free of red spider for 5 to 6 

 months after one application of sodium selenate to the soil in early spring. In 

 benches, treatments made in July kept the carnations free of red spider for 10 

 months, whereas untreated plants became heavilj' infested. 



Two forms of sodium selenate were used in the tests, pure selenate (NaSe02) 

 and a commercial product known as P-40, which is superphosphate impregnated 

 with 2 percent of sodium selenate. The pure sodium selenate was dissolved in 

 water at the rate of 100 grams per gallon, to make a stock solution; each quart 

 of stock solution was diluted with 25 gallons of water; and 1 quart of diluted 

 solution was applied to 1 square foot of soil. At this rate each square foot re- 

 ceived 3^ gram of sodium selenate. The P-40 was applied to the soil at the rate 

 of 3, 4, and 6 pounds per 100 square feet. At these dosages red spider was ef- 

 fectively controlled. Although no injury to carnations was observed from the 

 dosage of 6 pounds, a minimum rate of 3 to 4 pounds per 100 square feet was 

 sufficient for good control. At the rate of 3 pounds of P-40 per 100 square feet, 

 each square foot received J^ gram of sodium selenate. 



Carnation plants should be treated with sodium selenate after they are estab- 

 lished in the soil, and at least 4 weeks must be allowed for the effect of the treat- 

 ment to show. Some preliminary tests at Waltham indicated that pre-treatment 

 of the soil with sodium selenate at the rate of J^ gram per square foot, 6 weeks 

 prior to planting, may be a safe procedure. 



Variations in soil conditions and other factors may affect the results obtained 

 with sodiuin selenate. Young, actively growing plants have been observed to 

 respond mote readily to selenate treatment than older plants. Conditions which 

 affect movement of water into the plants are also limiting factors. 



