ANNUAL REPORT, 1936 65 



occurs in varying degrees wherever the plants are grown under glass, was found 

 to be due to improper assimilation of iron. A chemical analysis of normal and 

 chlorotic plants and inoculation tests with different chemical elements proved 

 to be a satisfactory means of determining iron deficiency in gardenias. 



The use of sulfur in small quantities and the use of organic or ammonia 

 sources of nitrogen were effective in preventing iron chlorosis. Plants severely 

 affected with chlorosis made very poor response to treatments with iron com- 

 pounds or soil amendments, and in some cases plants so affected never became 

 normal. 



Soil reaction alone was not a satisfactory means of determining whether or not 

 a particular soil was adapted to gardenia culture. 



Data for the past two years are being assembled for publication as a bulletin 

 at an early date. 



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

 agation technique and various chemical treatments do not appear to be of 

 much importance in the rooting of cuttings of gardenias. Soft-wood cuttings 

 rooted as readily as more mature wood. Cuttings taken from chlorotic plants 

 do not form as vigorous root systems as cuttings taken from normal plants. 

 Correct humidity and temperature in the propagating house were of primary 

 importance in successful rooting of gardenia cuttings. 



Since gardenias can be successfully grafted, this method of propagation 

 might be used to control nematode disease if a disease-free rootstock could be 

 found. 



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

 The varieties S. A. Nutt, Alphonse Ricard, and Beaute Poitevine were used in 

 this experiment. The maturity of cutting material, time of propagation, 

 location of cuts on cuttings, type of media, chemical dips, and sterilized sand, 

 did not appear to have any beneficial effect on the rooting of geranium cuttings. 

 Stem rot, or black rot as it is sometimes called, would seem to be the limiting 

 factor in successful propagation of geraniums since none of the various cultural 

 methods appreciably affected rooting. Also, the rot was extremely virulent 

 even with variation in conditions and technique. 



This past year cuttings from plants sprayed with Bordeaux in the field were 

 compared with cuttings from unsprayed field plants. It was reasoned that 

 if infection occurred in the field, spraying should give some appreciable control. 

 Spraying in the field did not reduce the percentage of loss of cuttings from the 

 rot disease. The percentage of rooting of cuttings from sprayed and unsprayed 

 plants is tabulated below: 



Percentage Rooted 



Variety Media Sprayed with 



Unsprayed Bordeaux 



S. A. Nutt Sand 59 14 



S. A. Nutt Sand and peat* 52 52 



Alphonse Ricard Sand 71 36 



Alphonse Ricard Sand and peat* 74 51 



Beaute Poitevine Sand 56 29 



Beaute Poitevine Sand and peat* 68 49 



*In the proportion of 4 parts of sand to 1 part of peat. 



Carnation Fertilizer Experiments. (Harold E. White, Waltham.) 

 Preliminary cooperative fertilizer studies are being carried on with nine carna- 



