SALTCEDAR 57 



IMPORTANCE 



Saltcedar has become the No. 1 wetland weed of the Southwest. 

 The tree is not only a detriment to waterfowl habitat on thou- 

 sands of acres of overflow and river-bottom land, but it also 

 causes serious economic loss (through transpiration) of great 

 quantities of water needed for irrigation, and harms grazing in- 

 terests by competing with grasses or other useful vegetation. In 

 addition, dense stands of saltcedar along some stream courses have 

 caused flood damage to adjoining land by impeding flow at high- 

 water stages. Bees get nectar from the flowers, cattle use the 

 thickets for shelter, and in some river basins the plant is consid- 

 ered desirable for erosion control, but on the whole it is much 

 more of a liability than an asset. 



CONTROL 



While saltcedar has been controlled quite effectively along irri- 

 gation and drainage canals by high-volume spray applications of 

 2,4-D, investigations by several agencies since 1951 have thus far 

 found no satisfactory, effective method of eliminating it from 

 river deltas, reservoir margins, flood plains, and other areas where 

 extensive thickets exist. Instead, tests have made it clear that 

 the plant is difficult and costly to control in these situations by 

 either chemical or mechanical means. Results with 2,4-D or 

 2,4,5-T sprays or with combinations of the two have been incon- 

 sistent. Generally, repeated treatments have been necessary, and 

 ordinarily fair to good results have been obtained only at dosages 

 of 2.5 or more pounds per acre. Basal spraying has been moder- 

 ately successful. 



Hundreds of acres of Federal refuges have been cleared of the 

 pest in the past few years by use of heavy equipment (bulldozer, 

 bush-and-bog disk, and rotary tiller) and by follow-up mainte- 

 nance. In general, sod or cultivated crops must be sown after 

 clearance, and in addition saltcedar seedlings need to be sprayed 

 periodically to prevent reestablishment of thickets. Mechanical 

 control followed by spraying of regrowth is generally regarded 

 as the best means of combating saltcedar, as indicated in point 11 

 of the following summary from a report (Arle, 1957) by H. Fred 

 Arle of the Bureau of Reclamation : 



1. Saltcedar is more difficult to kill on flood plain situations than along irrigation 

 channels and streams. 



2. Single spray operations have never given satisfactory total plant kill of adult 

 ealtcedar and only rarely have two repeated treatments eUminated 80% or more of the 

 plants. 



