19 



S. C. Maintenance of Drainage Channels . To (1) test, modify or 

 develop light machinery for removing silt and vegetation from 

 open channels; (2) determine effective and economical methods 

 for controlling aquatic plant growth in drainage channels, with 

 major attention to chemicals and equipment for applying chem- 

 icals; and (3) determine effectiveness of selected grasses on 

 ditch side slopes in reducing growth of undesirable plants, and 

 in reducing erosion of the side slopes. 

 Agr. Engin. 66 



Poisonous Plants 



Tex. Distribution, Abundance, Economic Importance and Control of 



Poisonous Plants on Range Lands. To (1) obtain information on 

 distribution and abundance of plant species toxic to range live- 

 stock; (2) secure and compile data on losses of livestock on 

 basis of weed species, season and area involved; (3) secure for 

 each species data on nomenclature, description, distribution, 

 sites of infection, toxic nature, etc. and methods of control; 

 (U) determine toxic species if and when losses warrant, by field 

 investigations and feeding experimentation; and (£) determine by 

 field experiments, quantitative and seasonal control data on 

 chemical control of toxic species in problem areas. 

 Range and For. 608 



Brush 



Ariz. Control of Noxious Shrubs on Southwestern Ranges . Study: 

 (1) influence of temperature, humidity, rainfall, and soil 

 moisture on effectiveness of mechanical methods of controlling 

 cholla and pricklypear cacti; (2) conditions and factors resulting 

 in variable kills of burroweed by 2,U-D and develop a consistent 

 and effective method of control. Learn: (3) factors affecting 

 control of turbinella oak by herbicides following burning; (U) 

 factors influencing control of creosotebush, whitethorn, and tar- 

 bush with herbicides. 



Agron., Range Mgt. 285 Coop. ARS, FS 



Ark. Herbicidal Brush and Weed Control for Range Development and 

 Pasture Improvement . To learn (1) effect of herbicides on woody 

 growth and pasture weeds, (2) succession of plants following 

 herbicidal removal of brush and small trees, (3) if additional 

 operations other than removal by herbicides are needed to improve 

 treated areas. 

 Agron. UOU 



