45 .^XM AL i:i:iM)iirs ov i •i:i'AKiMi:Nr of A<;Ki(T'LTrKi-:. vsm 
on liarhcrry .iiul urcdial material in tlie ininu'diate ])roxiniily of barberry 
biisbes lf(M eultnres were identified, coniiirisinK 24 dilferent races, tlie ratio 
of races to collections beinj; abont 1:0. From 04") collections of uredial mate- 
rial collected at a distance from barl>erries 832 cultures were identified. 
These comiiri.^ed 14 race.**, the ratio of races to collections being about 1:46. 
Several races obtained from barberry are much more virulent on certain 
varieties of wheat than tho.se obtained away from barberry. There is also 
further evidence that one of the races of rust most prevalent during recent 
years (race 50) originated on barberry bushes within the past 10 years. 
MORE STP:M KUfeT IN 1937 
There was very little evidence of stem rust overwintering in Texas and 
northern Mexico during the winter of ]9:50-.*)7. Late in .March and in April, 
however, rust developed rapidly in northern Mexico, and more or less sporad- 
ically in Texas, depending upon the amount of rainfall. P>y May 'V) there was 
from H-j to HO percent of rust on the winter wheat in the r.o.^que River Valley 
and 15 percent in the area north of Dallas. 
Winter wheat in northern Oklahoma matured nc.rmally. with little damage 
from stem rust. In eastern Kansjis eastern Nebraska, and westeni and north- 
ern Missouri crops were heavy and succulent, and a week to 10 days late. 
Weather favored rust, with the result that serious damage occurred, particularly 
in late fields of the more susceptible soft-wheat varieties. Severe damage to 
winter wheat has occurred also in western and northern Illinois arid <entral 
Indiana, with some damage reported from central-western Ohio, southern Wis- 
consin, southern Minnesota, and southern and eastern Snrth Dakota. L-x-al 
epidemics of stem rust have developed in the vicinity of barberry bushes in 
Virginia, West Virginia, and Pennsylvania, with a marked decrease in the amount 
of damage noted in areas where the eradication of barberry bushes has been 
largely accomplished. 
Stem rust is developing on susceptible varieties of spring wheat in western 
Minnesota, eastern South Dakota, and eastern North Dakota, and severe damage 
will most likely occur, particularly in late fields. 
SEVENTEEN ADDITIONAL SPECIES OF BARBERRY FOUND SUSCEPTIBLE TO 
ATTACK BY STEM RUST 
Further investigations were conducted to determine the susceptibility of certain 
species and varieties of barberry advertised in catalogs and trade .iournals. 
Those found highly resistant when testt^ under natural conditions were given 
further study under controlled (greenhouse) conditions in St. Paul. Minn. More 
than 150 different species and varieties of Bcrhcris have been brought together in 
the experimental plots at the foreign plant introduction garden at Bell, Md., and 
others are being added as they are encountered in connection with the nursery- 
inspection work or advertised for sale. 
Inoculations made during the year have proved that the following species and 
varieties are d(>finitely susc-eptible to attack by stem rust: Brrhcris hrtui/nna, B. 
tischlcri, B. (ictitKicaxtha, B. buIUita, B. chitrin, B. concoJnr, B. con.-<iniilif<, B. 
corallifuia, B. dnsnKinchyn. B. fnrrcrii. B. hybrids Carmine. Comet, and Coral, B. 
macfaranthn, B. poirctii var., iccichangcncit.sis. B. rchdcriann. B. nihrnstilla, 
B. vuh/dris a fiorc (jracilc, and B. wil'<on(ic sta pfinva. 
When certain species of barberry are found to be highly resistant to the disease, 
seedlings grown from seed produced on the resistant buslus are testetl as a 
further precaution against releasing, for intiM'state shii)ment, a variety or hybrid 
which, although itself innnune. might iiroduce susceptible seiMlliugs. 
During the year selected plants belonging to 40 sptnies wt're inoculated under 
greenhouse conditions, with. th(> result that '\ additional species, B. ntirirfniui. B. 
guiinpcUi, and B. parrifolid, are now definitely cla.^siMl as susceptible, and 4 
Kl)ecies, B. dirt j/ota, B. f/rdcilis, B. smif/iinioh ntd, and B. pinnata, have hoen 
determined as highly resistant. Further tests will be made, howevir, before 
these last are approved for propagation within the lu-otected area. 
ACCURATE IDENTIFICATION OF B.ARBKRRY IMPORTANT IN CONNECTION WITH 
la A R A N T I N E E N FO R ( I : M E N T 
The object of (^uaranl iiie No. .^H (revised) is to prevent, thmnuh iMlucalion an»l 
r<'gtilat ioiis. llie interstate mov(>ment (into or between States comprising the 
protected area) of susceptible siKvies of barlKM'ry. In conn»H'tlon with this 
