33 The Colorado Expeihment Station 
5. Hand pick disease-free pods, or if possible, select disease- 
free plants, for seed. Use these to plant a seed plat on land which has 
never raised beans and which is removed some distance from the main 
crop. 
Remember that hand picking of seed as it comes from the flail 
or thrasher for the purpose of controlling disease is of no value, since 
it is impossible to detect even a small percentage of diseased seed. 
6. Seed treatment for beans is of no practical value since any 
chemical that would penetrate the seed deeply enough to destroy the 
disease-producing organism would likewise be apt to kill the seed. 
7. Spraying with Bordeaux mixture, 5-4-50 formula, even when 
done thoroly by competent persons, is at best unsatisfactory, unprofit¬ 
able and only partially successful. However, if one desires* to try 
this, the first application should be made when the plants have their 
first set of true leaves, repeated ten days later, and again just after 
blossoming. Remember that if any real benefit is to be derived, the 
stems, leaves and pods must be kept covered with the spray material. 
✓ 
