4f) ANNUAL REPORTS OF DEPARTMENT OF AOFJOFLTURE, 1944 
stem rust yielded 1,455 isolates. Of these, 48 percent were race 56, 
24 percent race 38, and 23 percent race 17. Compared with the pre- 
vious year, there was ail increase in prevalence of race 5f> and a de- 
crease in races 38 and 17. bill no conspicuous change in trends. 
Race 8 of the oat sleni rust was sulliciently prevalent in 1043 to 
cause concern regarding its future effect on the performance of Boone 
and several other resistant varieties of oats, most <>f which were de- 
rived from Victoria X Richland crosses. More than 20 percent of 
the total isolates of oat stem rust were of races 8 and 10. both of which 
attack the new varieties. Although there have been indications dur- 
ing i he la>t 5 years that race 8 might become more abundant, the sharp 
increase in prevalence in 1943 was unexpected since the previous hign 
was about 6 percent in 1940. 
The identification of physiologic races of wheat stem rust from 
55 viable collections obtained from barberries, grains, and grasses in 
the Palouse area of Washington and Idaho resulted in 65 isolates com- 
prising 14 races. These were all identified as previously described 
races, although some of them could have been considered as new ones 
on the basis of minor but apparently consistent differences. These 
differences indicate that a great deal of recombination between races 
had taken place on the barberry bushes. Of these 14 races, the only 
ones found commonly elsewhere are 56, 17, and 38. These were by 
far the most prevalent in the Mississippi Valley, but each was isolated 
only once in the material from the Palouse area. It appears, there- 
fore, that there was relatively little, if any, interchange of rust be- 
tween this area and other wheat-growing areas in which the preva- 
lence of physiologic races is known. 
NURSERY INSPECTION 
Applications for permits to ship Berbi ris and Mahonia plants under 
the provisions of Federal Quarantine 38 were received from 42 nurs- 
eries during 1943, and 37 were granted. It was necessary to refuse 
2 applications because the nurseries were growing susceptible varieties 
and did not wish to remove them, and the approval of 3 applications 
Was delayed pending the eradication of susceptible plants. Few su>- 
ceptible barberry plants are now found in nurseries in the States par- 
ticipating in control work, and many nurseries outside the control 
area are restricting their stock to immune or resistant varieties and 
species. During the year IT nursery operators voluntarily destroyed 
700 susceptible barberry plants. 
INFORMATIONAL ACTIVITIES 
Informational activities during L948 were planned bo supplement 
the survey and eradication program, particularly in territory where 
work could not be accomplished as scheduled. In Minnesota .'«.'» coun- 
ties authorized bounties ranging from 2 to 5 dollars for reporting the 
location of barberry bushes. Numerous news items were written for 
publication, and J) papers of a popular or technical nature were issued. 
Progress is sweetpotato weevil control 
The wartime demand for increased food supplies has greatly stim- 
ulated sweetpotato production beyond the normal 7<» million bushels 
annually, and has Stressed the importance of protecting this valuable 
