Agricultural Research in N. H. 33 



tion will be sought as to the compounds possessing this property. For ex- 

 ample, various mineral oils will fluoresce. Various copper compounds ex- 

 hibit a characteristic luminescence. 



In the absence of this property it is proposed to treat a compound with 

 a fluorochrome which will impart to it the ability to fluoresce. A long list 

 of fluorochromes has been recorded in the literature. Some of them are sol- 

 uble in water, some only in selected organic solvents, while some exhibit in- 

 creased fluorescence when highly diluted or extended. 



With preliminary data at hand it is proposed to study leaves which have 

 been subjected to sprays or dusts under controlled conditions, in the depart- 

 ment laboratories or greenhouse. It is hoped that photographs may be se- 

 cured which will show in detail the nature and extent of deposits not other- 

 wise adequately visible. If this stage of the investigation is successful, a fur- 

 ther study will be undertaken involving deposits remaining on foliage after 

 artificial rain. 



The relationship of the nature of the deposit to its performance as an 

 insecticide will then logically be in order. Through co-operation with plant 

 pathologists the relationship of deposits of fungicides will be sought. Sub- 

 sequently, it may be possible to add a fluorochrome to sprays or dusts applied 

 under field conditions. It is hoped that leaves from sprayed or dusted plants 

 may then be detached and brought to the laboratory for study and for pho- 

 tographic record. 



W. C. O'Kane 



FORESTRY 



Sugar Maple Propagation 



About 1500 cuttings were gathered from high-yielding trees and placed 

 in sand in both outdoor and indoor beds. Particular emphasis was placed on 

 treatment of the cuttings with ammonium salts of organic acids possessing 

 hormone-like properties. These were indole-3-butyric acid and p-chlorophe- 

 noxy acetic acid. Some were treated with a new hormone powder, Dow 

 "Quick-root" No. 2. 



Certain individual treatments gave as high as 20 per cent rooting, but 

 the total number was only 15 cuttings, or about one per cent of the total. To 

 date no success has been attained in carrying the rooted cuttings on to pro- 

 duce larger trees. The small number rooted each year has prevented much 

 experimentation with variable factors affecting this. 



The seedlings from high-yielding trees appear to be doing well, but have 

 I'Ot made enough growth to justify setting them out in the spring of 1947. 

 They will rerriain in the transplant beds for another year. 



S. Dunn, C. L. Stevens 



Characteristics of Sap Flow 



The daily flow from two sugar maples and one gray birch was measured 

 throughout the winter from October 23 to April 28. Thermographs recorded 

 temperatures inside the trees, in the soil at the base of the trees, and in the 

 air nearby. On five occasions, during the spring, the sap flow was measured 



