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

Production Update:

Frost Damage: Frost injury is fairly common for alfalfa grown in Arizona during the winter months. Leaves can be damaged by a "radiation frost" which can occur at air temperatures above 32 F. Conversely, alfalfa leaves can escape damage at temperatures as low as 27 F under certain conditions. The amount of frost injury that occurs depends on several factors. Nondormant alfalfa cultivars are more susceptible to frost damage than more dormant cultivars. A rapid rate of temperature decline is more damaging than a slow rate. Humidity in the air can contribute to frost damage. A cold hardening period before the frost can lessen frost damage. Food reserves accumulated by the plant can also lessen susceptibility to frost.

Insect Management: Egyptian alfalfa weevil (picture) populations buildup in hay fields during the early spring. Sample alfalfa fields every 2 to 4 days after weevil larvae first appear. Sample each field quadrant by taking 5 sweeps with a standard net. Count the number of weevil larvae (picture) in each 5 sweep sample and add the totals for each of the field quadrants. Divide the grand total for the field by the total number of sweeps (20). The field should be treated with an insecticide registered for weevil control when the average number of larvae reaches or exceeds 20 per sweep. If sweep counts are 10 to 15 larvae per sweep just before cutting, then applying malathion under the windrows may be considered. Avaunt is a newly registered insecticide for alfalfa hay production that will control EAW.

Weed Control: According to L1080 forms summarized by the Arizona Dept. of Agriculture, the most commonly used herbicide in Arizona in 2002 was Trifluralin. 55,576 acres were treated with this herbicide which was almost twice that of any other herbicide. Second was Kerb (29,734) followed by Pendimetanlin (Prowl, Pendimax etc.)

10 Year Summary (Dec 30 - Jan 12, 1995-2004):

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.