71 ANNUAL REPORTS OF DEPARTMENT OF AGRICUI/TURE, 1951 
Barberry Eradicated to Control Stem Kum 
New race* of rust cause local grain losses 
Wide occurrence of highly virulent new races of the wheal and oat 
varieties of stem rust caused serious grain losses in L950. Thisdi 
reduced late crops of durum wheat in North Dakota and Minnesota 
by about 20 percent, or an estimated 1<» mill ion bushels. Late fields of 
hard spring wheat also were seriously damaged. Oat Losses amounted 
i vera] million bushels in Iowa. Illinois, and Wisconsin. They 
were caused by race L5B of the wheat-stem rust and race 7 of the oaf- 
stem rust, both of which originated on barberry plants. These races 
can attack and damage all the important commercial varieties of 
wheat and oats. In past years both races were found occasionally near 
barberry bushes in the Bast. In L950 they appeared in many Si 
causing severe damage to late crops of wheat and oats. 
More than 20 million barberry plants hilled 
More than 20 million native and introduced rust-spreading bar- 
berry bushes were killed in 28± count ies in I s cooperat ing St ates and 
31,261 square miles were treed of barberry. Barberry sites within 
an area of 5,000 square miles that became reinfested during the war 
years were completely reworked. 
Territory freed of barberries kept free 
More than 80 percent of the area in the 18 barberry-eradication 
State- has been freed of rust-spreading bushes and is being kept free 
of them. This is accomplished by nursery inspection, quarantine 
enforcement, disease surveys, recheck of previously infested proper- 
tit-, and encouragement to farmer.- to promptly report any barberry 
plants they may find. No further organized searching for barberries 
is contemplated in these areas unless some bushes are reported or 
located through maintenance activities. 
Territory freed of barberries includes areas found free of the plants 
when initially examined and barberry-infested sites worked at peri- 
odic intervals until permanently cleared of the plant-. All territory 
in what is termed a control area is initially examined for barberry. 
Site- found infested are systematically searched and all rust-spread- 
ing barberries are destroyed. These places are reworked at 5- to 7- 
year intervals to remove any seedling plants before they an' old 
enough to seed and reinfest the territory. A.bout three workings are 
:u\ before infested sites can he freed of barberries and placed 
on maintenance because seeds in the -oil can remain viable for 12 
years. Reworking at intervals allows time for seeds to germinate and 
ih'w plants to become large enough to he found, yet not old enough 
to produce -fed. These practices systematically exhaust seed sources 
and lid areas of barberries. Man\ year- of practical experience have 
demon -i rated t heir effect h eness. 
Vein movie stimulates control 
A new color-sound movie film, "Stem Rust AJrborne Enemy of 
Grain," was released. < Copies were sent to 35 film libraries in the con- 
trol States. The film was shown at 286 meetings and seen by about 
15,000 people in L950. 
