May, 1921] BIENNIAL REPORT. 19 



value of alcoholic and ethereal extracts; repellent properties; poisonous prop- 

 erties with relation to vertebrates. 



Control of Black Flies. — Biological observations made up the work under this 

 project during the period. In order to secure a larger volume of data concern- 

 ing the relative abundance of various species of black flies in the state, coUect- 

 tions of larvae were made at numerous points and the species determined. 



Department of Forestry. 



Artificial Forests. — This project is intended to secure data upon the growth 

 and yield of exotic tree species which are suitable to New Hampshire climatic 

 conditions. These plots were started in 1913, so that they are beginning to 

 show results. 



Thinning of Immature Stands. — Twenty-six sample plots have been estab- 

 lished under this project in the vicinity of Durham. They are being re meas- 

 ured annually. The data from these plots can be used directly in estimating 

 yields on farm wood lots. 



Department of Horticulture. 

 Variety Testing of Fruits. 



Thompson Apple Orchard. — Records of blossoming and yields were kept this 

 season. The most notable feature of this variety orchard is that all the origin- 

 ally planted Mcintosh trees have grown well, and are now fruiting well on soil 

 conditions which are usually held to be not at all suited to apple culture. On 

 a wet stiff clay soil that killed out the original Baldwin trees and succeeding 

 lots of trees planted between the Mcintosh this latter variety has thrived. 



Several varieties fruited for the first time this past season in this orchard — 

 notably, Liveland Raspberry, Delicious, and Northern Spy. The "Delicious" 

 were of fair size and very good quality. The trees in general are now making 

 better growth than they have in the past, owing to the added fertility which is 

 being supplied from poultry droppings. During the summer the hens and 

 chickens have full run of the orchard. 



The Plum Orchard. — This orchard did not produce a crop during the season 

 of 1920, owing to the killing of practically all the fruit buds during the previous 

 winter. During the previous years the outstanding feature has been the suc- 

 cess of the variety Burbank. 



Strawberries. The variety plots of strawberries yielded well this past season, 

 and records were made of the character of the blossoms, the nature of the foli- 

 age, and condition of the plants together with the total yield in quarts for each 

 variety. 



A bulletin covering the strawberry work at the Station together with notes 

 secured from growers throughout the state has been prepared for publication. 



Raspberries and Blackberries. — This experiment comprises a fertilizer and 

 manure test on two rows of Cuthbert, one row each of Marlboro, Perfection 

 and Herbert raspberries, and on one row of Snyder blackberries. Six plots, 

 approximately one-tenth acre each, are laid out crossing these varieties, and fer- 

 tilizer and manure treatments have been applied. There was a very evident 



