650 EXPERIMENT STATION RECORD. 



Notes are given on the depreciation of forest trees and results of the 

 faihire to cut trees at maturity. Numerous examples are g'iven of 

 depreciation in value attributed to decay, and various signs of decay 

 are pointed out. 



The undesirability of i-ed and black oaks, because of fungus diseases, 

 is mentioned. These oaks, particularly the l)lack oak, are specially 

 subject to a disease of the same nature, if not identical, with the canker 

 of the apple tree {Nectr'ui ditissiina). It is said that few trees incurring 

 this disease overcome or outgrow it and, as a rule, they fail completely 

 before attaining a diameter of 10 in. at the base. The disease is much 

 more common in sprout or coppice growth than in seed-grown trees. 

 A judicious selection should be continualh^ carried on during the earlj'' 

 years of forest growth, cutting out the undesirable species and par- 

 ticularly every tree which shows the beginnings of disease. The white 

 oak seems to be entirely free from this disease, while most of the other 

 species are affected to a greater or less degree. 



Notes are given on the injur}' produced on white pine by the pine 

 weevil. It is said that one of the most serious obstacles to the growth 

 of the white pine is the pine-tree weevil {Pissodes st?'ohl), a small beetle 

 which la^^s its eggs in the 3"0ung terminal shoots and occasionally in 

 the uppermost laterals. The young grubs bore through the bark to 

 the wood, completely destroying the shoots. The ravages of this 

 insect are said to be very common, destroying during the past year the 

 tops of at least 10 per cent of the white pine trees, as well as seriously 

 attacking Norway spruce and other ornamentals. 



Notes are given on various shade trees for street planting. The 

 tulip and magnolia on good loamy soils, with plenty ^f room and good 

 drainage, are said to be well adapted to this purpose. They should 

 not be set closer than 50 ft., and 00 ft. is better. The same conditions 

 appl}' to the sycamore and elm trees. Maple trees vary considerably 

 with the different varieties. The silver maple gives the quickest 

 results with possibly one exception of an}' shade tree, but for best 

 growth requires a moist fertile soil. The hard maples are considered 

 among the most desirable for shade trees, succeeding well on a variet}' 

 of soils, and are believed to be nearly free from insect or fungus attacks. 

 The European species, while generally more rapid in growth during 

 early life, are said to soon reach the limit of growth and never make 

 as large trees as the American species. 



The Cottonwood and other poplars, on account of their rapid growth, . 

 are frequentl}' recommended for street trees, but they do not last as 

 well as some other A-arieties and become very unsightly with age. The 

 tendency to sprout from the root is also considered objectionable. The 

 objections urged against the cotton wood are said to apply to ailanthus, 

 and in addition this tree has an irregular habit of branching, so that 

 old trees become verv unsvmuietrical. 



