SAFEGUARDING THE WHITE PINE CROP 



11 



1920, in the New England States, 682 checks were made 

 by these various methods, on areas totalling approximate- 

 ly 6,000 acres. The crews that went over these areas 

 the first time destroyed 97.2 per cent of the total number 

 of bushes. 



In Wisconsin and Minnesota, white pine blister rust 

 is widely distributed on currants and gooseberries and 

 is attacking pines at a number of points. In Minnesota 

 infected currants were found as far north as Tower 



Photograph by A. B. Brooks. 



ONE YEAR OLD SPROUTS OF WILD GOOSEBERRY BUSH 



This growth resulted from breaking off the top of a large bush. The 

 crews use specially constructed digging implements and the entire 

 crown of the bush is taken out and hung up so it cannot grow again. 

 Wild currants and gooseberries do not reproduce rapidly in an area 

 that has been worked by an efficient crew. Thorough checking on 248.5 

 acres in 8 separate tracts previously gone over by eradication crews.- 

 showed that on an average acre, 62 bushes (95.5 per cent) were destroyed 

 in the first working and 3 bushes in the second working. Of the 

 latter, two bushes were missed in the first working, and one bush 

 developed from seeds or sprouts. Bushes missed by the crews usually 

 are small plants growing in underbush. Such plants have less leaf 

 surface than the average plant; therefore, the total percentage of 

 protection lo the pines is considerably greater than the total per cent of 

 currant and gooseberry bushes destroyed. 



and as far west as Grand Rapids. Local control areas 

 were established in these States in 1920, resulting in 

 11,672 acres cleared of currants and gooseberries at an 

 average cost of $1.04 per acre. During the past season, 

 no blister rust was found outside of the above-mentioned 

 States, with the exception of two "spot" infections on 

 black currants in New Jersey. The "spot" infections 

 found in Michigan and Pennsylvania in previous years 

 appear to have been successfully eradicated, and in New 

 Jersey the disease is apparently under control. 



The Rocky Mountain and Pacific Coast forests are as 

 yet apparently free from the white pine blister rust. 



During the past three seasons, 146,929 white pines, and 

 318,093 currant and gooseberry plants have been traced 

 and inspected in the far West. These plants were ship- 

 ped from infected regions prior to enactment of quaran- 

 tines, and were, therefore, possible carriers of the blister 

 rust. None of these were found to be infected with the 

 disease. Active scouting for the blister rust is in prog- 

 ress on wild currants and gooseberries and introduced 

 host plants, but no signs of the disease have been found. 

 Sixty-five species of currants and gooseberries are in- 

 digenous to western North America. Out of this large 

 number, there are species adapted to nearly every site 

 condition existing in these regions, and they afford an 

 unbroken chain for the dissemination of white pine 

 blister rust, if the disease is once introduced into this 

 region. A single shipment of diseased pines, currants or 

 gooseberries may result in enormous losses, both to pri- 



A CREW UPROOTING WILD CURRANT AND GOOSEBERRY 

 BUSHES TO PROTECT NEARBY PINE STANDS 



The men work in line formation, the spacing between men varying 

 according to character of the land. The number of men In line varies 

 from four to six, although for most conditions, five men Is considered 

 preferable. Small bushes are pulled by hand, and larger ones dug up 

 with specially constructed "Rihes picks " The foreman follows closely 

 in the rear of the crew and clucks their work. The work of each 

 crew is also checked frequently by Federal inspectors. As a result of 

 many large-scale experiments, modifications of the general method 

 have been developed. Thus, there are special "stone-wall crews," 

 "checking crews," "advance Ribes scouts." a "head linesman," and a 

 "chemical crew." The methods are not elaborate, and unskilled labor- 

 ers, working under a trained foreman, quickly learn to do excellent work. 



vate and Government holdings. Sugar pine, western 

 white pine, and limber pine, the three most important 

 five-leaved pines in the West, are known to be highly 

 susceptible to the white pine blister rust. The confer- 

 ence, therefore, urged that great attention be paid to the 

 strict enforcement of the Federal quarantine prohibiting 

 shipment of blister rust host plants west of the "Missis- 

 sippi Valley line." 



FINE YIELD FROM WHITE PINE 



TWO acres of white pine, near Keene, New Hamp- average of 85,000 feet per acre. The trees were from 



-*- : : hree Dr four years ago, before the 80 to 85 years old; so the growth on each acre was about 



war prices, for $2 ~;oo on the stump. The total stand 1,000 feet per annum and the gross returns about $12.20 



was 254 cords, which equals 170,000 board feet, or an per acre per annum. 



