after uncontrolled fires (fig. 5). Both woody species and herbaceous species are 

 found in brushfields; the species composition will vary by location. Because all plant 

 species are not affected to the same degree when any one herbicide is applied, more 

 than one chemical may be required. In central Idaho 3 satisfactory results have been 

 obtained with aerial applications of 2,4,5-T and dalapon applied in 2 successive years 

 at the rate of 8 gallons of spray per acre. Concentration dosages were 3 pounds acid 

 equivalent (a.e.) of 2,4,5-T and 20 pounds of dalapon in 1 gallon of diesel oil and 

 6 gallons of water. Another area sprayed with 3 pounds a.e. of 2,4,5-T in 7.25 gallons 

 of diesel oil produced satisfactory kill of shrub vegetation. Handspraying similar 

 areas with more dilute solutions [4 pounds a.e. of 2,4,5-T and 20 pounds of dalapon 

 in 200 gallons of water) gave equally good results. The solutions containing dalapon 

 successfully reduced competition from grasses and sedges on the site. 



Other herbicides have been used successfully on brush species in the northern 

 Rockies (Potter 1968, Ryker 1966) . New herbicides are being discovered and developed 

 rapidly and will increase the flexibility and usefulness of chemical treatments. 

 Foresters can use chemicals to prepare sites for regeneration, but they should choose 

 the chemicals carefully and recognize their limitations. For example, herbicides that 

 successfully kill growing vegetation may not kill plants that grow from seed in the 

 soil after spraying. Chemical sterilants or preemergence phytocides may control 

 germinating weed seeds, but residual chemical in the soil may be toxic to tree seedlings 

 if they are planted too soon. Herbicides can be valuable tools if the right chemical 

 is used according to tested procedures. Foresters need to be aware of current develop- 

 ments in order to make effective use of chemical site preparation. 



Figure 5. — Aerial application of herbicides to a brush field preparatory to planting has 

 been found helpful. This field is in central Idaho. 



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