ANNUAL REPORT. KHd 83 



was the most consistent, giving 100 percent rooting at 60°, 65°, and 70° F. 



Indoleacetic acid, 25 mg. per 100 cc. for 24 hours, was also consistent, 

 with rootings of 100 percent at 60°, 65°, and 70° F., but with somewhat 

 smaller root systems. 



Indolebutyric acid in the form of Hormodin A (60 BTI units for 40 

 hours) and of Hormodin Powder No. 3 gave 100 percent rooting at 70° F. 



In general, the rooting of treated hemlock cuttings was definitely accel- 

 erated at higher temperatures, but the percentage of rooting was not as 

 high as that obtained from the same treatment at lower temperatures. 

 In opposition to this trend, a single treatment at 75° F. gave a good per- 

 centage of well-devdoped rooting as early as nine weeks. 



Similar trials are planned for the coming season at like temperatures 

 with more varied treatments. Three series of cuttings will be taken from 

 December to late February at five-week intervals. 



A series of identical treatments was made with cuttings of Carolin.H 

 hemlock,, Tsuga CaroHniana, taken about December 12, 1939. 



Only the strongest concentrations of indoleacetic acid solutions brought 

 rootings of over 50 percent, requiring about five months. The response 

 at 75° F. was negligible. At 70° F. a response of 20 to 40 percent was 

 general from most treatments. The highest percentages of rooting came 

 from the following treatments. 



Percent of 



Rooting Treatment 



75 2h mg/100 cc Indoleacetic Acid 24 hrs. at 65° F. 



• 58 25 mg/100 cc Indoleacetic Acid 40 hrs. at 65° F. 



58 50 mg/100 cc Indoleacetic Acid 40 hrs. at 65° F. 



67 50 mg/100 cc Indoleacetic Acid 40 hrs. at 60° F. 



Propagation of Lilac. (Harold S. Tififany, Waltham.) Terminal cut- 

 tings were taken on May 28, 1940, of the common lilac, Syringa vulgaris var. 

 Andenken an Ludzmg Spaeth, in lots of 75 for each treatment (except un- 

 treated lots with 15 cuttings): (1) Hormodin A solution 40 BTI units 

 for 24 hours: (2) Hormodin Powder No. 3; (3) Formula "66"; and 

 (4) untreated, at each of the constant temperatures, 75°, 70°, and 65° F. 

 and an unheated bench. The medium consisted of two-thirds sand and 

 onf;-third domestic peat. Cuttings were shaded by cheesecloth tents and 

 lime on the greenhouse glass. Constant temperatures were maintained 

 for the first five weeks only. 



At the end of nine weeks the cuttings were potted. A temperature of 

 70° F. gave the highest percentage of rooting; Hormodin A, 99 percent; 

 Formula "66", 96 percent; the untreated lot, 93 percent. Many of the 

 untreated lot, however, were not sufficiently well rooted for potting. 

 Constant temperature of 75° F. brought but one high percentage of root- 

 ing; 92 percent with Hormodin A. In general, rooting percentages 

 mounted fairly constantly from lows with uncontrolled temperature 

 through 70° F., and dropped decidedly at 75° F., because of burning. 



All potted cuttings are in good condition with the exception of twenty- 

 seven losses. 



Factors Influencing the Hardiness of Evergreens. (Harold S. Tififany, 

 Waltham.) Plots of Taxus haccata repandans and Taxus canadensis stricta, 

 set in the spring of 1939, received the first series of cultural treatments 

 this season. Treatments were designed to produce widely varying types 



