ANNUAL REPORT, 1935 59 



and continuing until March, had no noticeable effect on recovery from chlorosis, 

 on bud drop, or on production. 



A canker disease observed on plants at the Waltham Field Station has been 

 found to be of economic importance in local greenhouses. This disease is to be 

 included in the present studies. 



A paper on the gardenia experiments is to be presented at the meetings of 

 the American Society for Horticultural Science in 1935. 



Propagation Studies on Gardenias. (Harold E. White, Waltham.) 

 Gardenias rooted equally well whether the nodal cut was made through, above, 

 or below the node. Leaf cuttings root readily, but a bud or eye must be present 

 for normal growth; for, although roots will form, development of shoots does 

 not take place when the entire bud is not present. Potassium permanganate 

 treatment did not seem to hasten rooting, while a .05 molecular solution of 

 cane sugar appeared to increase rooting. The type of rooting medium apparently 

 did not affect rooting: but in a peat and sand mixture, the roots, once they had 

 formed, made more rapid growth than in sand. 



A period of six to seven weeks is required for rooting gardenia cuttings. High 

 humidity is an essential condition. An increase of 30 percent in humidity was 

 observed when propagation was carried on under an enclosed frame as com- 

 pared with the open bench method. The enclosed frame method with a bottom 

 heat of 60° and a humidity of around 80 percent shortened the rooting period 

 about one week. 



There was an increase of from 40 to 50 percent in rooting of cuttings taken 

 from sand plots as compared with those from soil plots. This increase may have 

 been due to the fact that the sand plots showed less interveinal chlorosis. Roots 

 on cuttings taken from normal plants were more abundant and vigorous than 

 on cuttings from chlorotic plants. 



Gardenia canker was observed on cuttings in the propagating bench of a 

 commercial range, indicating that this disease may be carried over on the 

 cuttings. This condition has not been observed at the Waltham Field Station, 

 probably because the disease, while present, has not been severe this season. 

 Infection of the cutting material is quite possible inasmuch as the practice is 

 to take cuttings near the bottom of the plants where the spores could be splashed 

 up from the soil and from cankers at the base of the plants. 



DEPARTMENT OF HOME ECONOMICS 

 Helen S. Mitchell in Charge 



Cause and Control of Nutritional Cataract. (H. S. Mitchell and O. A. 

 Merriam.) The production of nutritional cataract in rats fed on lactose or 

 galactose has been previously demonstrated. In a new series of over 100 

 animals there was an 85 percent incidence of mature cataract on the 70 percent 

 lactose ration, 100 percent incidence on the 35 percent galactose ration, and 

 none where other carbohydrates were used. A study is now being conducted 

 into the metabolic disturbances involved, other pathological manifestations, 

 and possible means of prevention and cure. So far a mature cataract once 

 formed has never been made to disappear. Certain alterations in the com- 

 position of the rations suggest a slight hastening or retarding of cataractous 

 changes. Different strains of rats show variable susceptibility to cataract 

 formation. 



