Research Problem and Background:
The Bureau of Reclamation has thousands of miles of water distribution canals, rights-of-way, wetlands, wildlife resources, recreational areas, and reservoirs at significant risk to damage by weeds and other pests. As a major national water resource management agency, the spread and establishment of harmful weeds is in direct conflict with Reclamation goals to provide prudent and cost effective management of Western water reservoirs. In addition to the millions of acre-feet of water lost annually as a result of such infestations, Reclamation is also concerned that harmful weed species are spread by its water distribution systems, and that their growth is encouraged and enhanced by system operations.

Research support and development is needed to implement Department of the Interior policy mandating the use of IPM (Integrated Pest Management). This research applies to agency goals of water resource management through protecting the environment (water-quality) and safeguarding the public investment through facility maintenance and improvement. Information is needed to provide compliance with the Federal Noxious Weed Act and policies of the Department of the Interior by providing technical assistance and development of special studies and demonstration projects to promote IPM concepts and to solve specific pest problems on public lands using IPM.

Major research needs also exist in identifying and developing alternatives to using herbicides for aquatic weed control and in improving herbicide-use techniques to achieve significant reduction in the amounts that are used. New techniques are necessary to reduce operating costs and increase pest management efficiency by providing more environmentally acceptable, less expensive alternative, and by reducing pesticide application rates, frequency of treatment, and labor. Additional intangible benefits include reduced environmental impact, better control of system operations, and expanded knowledge of pest biology.

Project Objectives:
Aquatic site weeds, algae, and other organisms in Reclamation water systems produce large biomass which obstructs water flow, prevents access for maintenance and recreation, causes structural damage, and otherwise negatively affects system operation, water quality, and wildlife habitat. The purpose of this research has been to develop integrated pest management techniques (IPM) for Reclamation water storage and conveyance systems incorporating chemical, mechanical, and biological elements with the goals of improved operational efficiency and reduced adverse environmental impacts. The scope of this research has included development in the following categories: (1) biological control agents to reduce dependency on pesticide use, (2) improved pesticide application techniques to reduce environmental contamination and cost of treatments, (3) environ-mentally compatible pesticides to reduce impact on nontarget organisms, and (4) pest physiology investigations to identify weaknesses or control points in a pest’s life-cycle. Special attention is given to introduced (non-native) and noxious weeds which can, in the absence of natural enemies, produce particularly troublesome and costly problems.

Overall Outcome or Conclusions:
Biological control is demonstrably successful with purple loosestrife and, to a lesser extent, with leafy spurge, an extremely aggressive weedy species. Reclamation has initiated biological control of Yellow Star Thistle at Red Bluff, California. Monitoring of biological control insects and plants is ongoing, and some aerial and GPS mapping techniques have been demonstrated to be successful.

An automated chemical metering system (ACMS), which adjusts for changes in flow, has been developed to provide a specific low rate of herbicide concentration is maintained for a range of 84-120 hours. Such low concentration reduces the impact on non-target organisms.

Four environmentally compatible aquatic herbicides have been evaluated in large hydraulic flumes with good efficacy, but patent right disagreement from two co-owners prevented Reclamation and the Army Corps of Engineers from continuing this research using encapsulated matrixes.

Research was initiated into the reproduction and use of saltcedar biocontrol insects in field situations.

Partners:
Cooperative work continues with the Corps of Engineers and local water districts on evaluating reduced rate applications of endothall. The manufacturer of the herbicide agreed to provide the necessary product and to conduct herbicide analysis of water samples. The manufacturer is interested in applying for a license to use a metering system.

Joint work continues with the Pacific Northwest Region and the Ephrata Field Office on development of biological control techniques for large scale purple loosestrife management. Work expands between our office and the Dakotas Area Office to include cooperative development of an Integrated Pest Management Plan.

Our office staff formed a cooperative grass carp research effort in New Mexico with the Navajo Agricultural Products Industry. Cooperative research efforts were also formed in Oregon with the Bend Field Office; Portland State University; Talent Irrigation District, Medford, Idaho; Rouge River Valley, Idaho; and the Oregon Department of Fish & Wildlife.

Our office staff expanded scope of cooperative work with Cornell University to include producing artificial diets for biocontrol insects and developing standardized methods of sampling and monitoring biological control research efforts. Our office is developing a cooperative group for the development of biological control insects for salt cedar the group includes the USDA-ARS, the Colorado Area Office, the Colorado Division of Wildlife, and the Colorado Department of Agriculture.

Our office is developing a cooperative new agreements with USDA (for salt cedar control insect) and USGS (for iron bacteria).

A joint program with Spain is showing good results in area of aquatic plant and algae control with herbivorous fish.

Publications and/or Other Deliverables
1996 Idaho and Colorado Metering Studies Utilizing Aquathol K for Aquatic Weed Control in Flowing Water. Technical Memorandum No. 8220-97-12.

Control of Aquatic Vegetation in Irrigation Reservoirs of Southeastern Spain by the Use of Grass Carp (Ctenopharyngodon idella) (In Spanish) . Joint Report USBR - CEDEX (1994).

Control of Aquatic Vegetation in Irrigation Reservoirs of Southeastern Spain by the Use of Grass Carp (Ctenopharyngodon idella) (In Spanish). Joint Report USBR - CEDEX (1995).

Control of Aquatic Vegetation in Irrigation Reservoirs of Southeastern Spain by the Use of Grass Carp (Ctenopharyngodon idella) (In Spanish). FINAL REPORT - USBR - CEDEX (1997).

Low-Dose Metering of Endothall for Aquatic Plant Control in Flowing Water. In the proceedings of the Journal of the Aquatic Plant Management Society, vol 36, January 1998.

Low-Dose Metering of Endothall for Aquatic Plant Control in Flowing Water. Technical Memorandum No. 8220-98-13.

Pest/Management Resource Protection Plan for the South Columbia Basin Irrigation District. Technical Memorandum No. 8220-98-8.

Precision of an Automated Chemical Metering System in a Fluctuating Canal-1997. Technical Memorandum In Draft.

Purple Loosestrife Biocontrol Research Program at the Bureau of Reclamation Technical Service Center - Summary of 1995 Activities. Technical Memorandum No. 8220-96-13.

Purple Loosestrife Biocontrol Research Program at the Bureau of Reclamation Technical Service Center - Summary of 1996 Activities. Technical Memorandum No. 8220-97-5.

Reduced Rate Endothall Application For Controlling Sago Pondweed in High-Flow Environments/Summary of 1994 Study. Technical Memorandum No 8220-96-12.