Curly top is transmitted by a single species of leafhopper, and its 
occurrence is limited to the West where the insect occurs. In some 
areas where the disease and the vector are most prevalent, curly 
top prevents the prodiction of susceptibie crops, incliding heans., 
Losses of seed snap beans are caused chiefly by root rots and 
virus diseases. Rust has not caused much loss in the seed crop, 
and bacterial blights are less severe because most of this crop 
is grown in the semi-arid West. Halo blight, however, causes some 
loss. Curly top is responsible for about as much loss as in dry 
beans. Baldhead, which results from threshing injury, also causes 
considerable loss in seed beans. 
Root rot can be controlled to some extent by chemical seed treat=- 
ment and crop rotation. Bacterial blight losses are reduced by 
using seed produced in the dry areas of the West where blight is 
not epidemic. Losses from rust can be greatly reduced by dusting 
with sulfur. There are a number of bean varieties resistant to 
common bean mosaic and some field bean varieties resistant to curly 
top. As yet we have no varieties resistant to bean yellow mosaic. 
Losses in dry lima beans are caused chiefly by the root rots 
affecting dry beans and seed beans. 
Dry Peas (including seed peas) 
Losses from disease in dry peas and seed peas are due principally 
to root rot. Less severe losses are caused by ascochyta leaf spot, 
bacterial blight, powdery mildew, and mosaic viruses. 
Root rots are difficult to control because the organisms persist 
in the soil, but crop rotation tends to prevent losses from becoming 
more severe each year. Use of clean western-grown seed treated 
with a fungicide helps to reduce loss from ascochyta and 
bacterial leaf blights. Virus diseases are not controlled. 
Flax 
Rust, pasmo, and wilt are the important flax diseases in the United 
States. Anthracnose seedling blight and heat canker are also rather 
widely distributed and occasionally cause losses. The prevelence 
and destructiveness of the diseases vary from season to season, de- 
pending on weather conditions and, with rust, on the prevalence of 
races of the disease organism that may attack varieties widely grown. 
Losses from rust averaged 3 percent during the 10-year period and 
were rather high in 1943, 1950, and 1951. Losses vary greatly from 
year to year, usually being worse in years of heavy rainfall. Rust 
causes a reduction in yield and in quality of the flax seed and fiber. 
ey yaa 
