University of Arizona a dot Cooperative Extension

Alfalfa Report
Yuma County, Arizona
May 20, 2002

Yuma County Office
2200 W. 28th Street, Ste. 102
Yuma, AZ 85364
(928) 726-3904
(928) 726-8472 FAX

Production Update:

Alfalfa sensitivity to water stress: Alfalfa is most sensitive to water stress after a cutting. Yield losses as much as 30% have been reported for delaying irrigation after cutting by 6 days. It is impossible, of course, to irrigate immediately after cutting when producing alfalfa hay. However, the irrigation before cutting could be timed so that soil moisture is available for regrowth after cutting. Caution must be exercised to avoid soil conditions that are so wet at cutting that compaction results, which has long term consequences perhaps more serious than soil that is too dry at cutting.

Insect Management: Spider mites (Detour signpicture, 71KB) are not common in alfalfa grown for hay and serious damage is often associated with water stress. When infested fields are watered, the problem often clears up in a matter of days. In recent years, spider mites have been more common in alfalfa hay fields during the spring/summer months. Spider mites infestations are usually confined to the lower leaves. They feed by inserting long needle-like mouth parts into leaves removing plant sap. Leaves become stippled with chlorotic spots. Infested leaves are covered with webbing and turn yellow. With severe feeding, leaves turn brown from necrosis and desiccation causing defoliation. Damage starts in the lower plant canopy moving upward. Feeding damage can reduce yield, quality and retard growth. Definitive monitoring and treatment guidelines have not been developed for spider mites in alfalfa grown for hay.

Weed Control: The time has passed when the contact herbicides, Gramoxone and Buctril, can be safely and effectively used in alfalfa. Hot, dry conditions, rapid crop regrowth, and preharvest intervals make it difficult to safely and effectively use these products between March and October. They also are weak on grasses, which are the predominate summer weeds.

Market Summary
Off grade
Past 2 Weeks (May 7 - May 20, 2002)
Last Year (May 7 - May 20, 2001) 100 90 95 80-90


10 Year Summary (May 7 - May 20, 1993-2002):10 year summary May 7 - May 20, 1993 - 2002

Full Disclaimers

Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, James A. Christenson, Director Cooperative Extension, College of Agriculture and Life Sciences, The University of Arizona.

The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.

Any products, services, or organizations that are mentioned, shown, or indirectly implied in this web document do not imply endorsement by The University of Arizona.

Information provided by:
Barry Tickes, Extension Agent, Yuma County
Michael Ottman, Agronomy Specialist
College of Agriculture, The University of Arizona.
Eric Natwick, UCCE Imperial County - Farm Advisor
University of California, Davis, CA.

Yuma County: Field Crops | Farm Notes | Alfalfa Reports | Vegetables

Forages: Crop Mgmt | Soil Mgmt | Irrigation | Alfalfa Reports | Insects | Diseases | Weeds | Pesticides
Home | Other Crops | Forages

For more Arizona Production Ag Information:
Home | Cotton | Veggies| Forages | Grains | Citrus | Crop x Crop | Insects | Diseases| Weeds | Pesticides | News | Weather | Research | Photos | Contacts | General Info. | Site Map

document located at:
Copyright © 2001 University of Arizona,
College of Agriculture and Life Sciences
Webmaster: Al Fournier (