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

Production Update:

Arizona Alfalfa Acreage: Acreage of harvested alfalfa hay in Arizona has averaged about 176,000 acres between 1919 and 2002. Alfalfa was grown in the 1800's in Arizona, but acreage was not reported until 1919. The lowest acreage was 82,000 in 1920 and the highest acreage was 237,000 acres in 1944. The 2002 acreage of 225,000 acres is the 5th highest in 84 years of reported acreage. Alfalfa acreage has increased steadily since 1993, when alfalfa hay was harvested from 150,000 acres.

Insect Management: The granulate cutworm, Agrotis subterranea (Fabricius) (picture) can be a devastating pest of alfalfa. They often go undetected until after cutting and hay removal. When fields are watered back, there may be areas with little regrowth due to cutworms feeding on new shoots from alfalfa crowns. Granulate cutworm is nocturnal and will move from cracks in the soil or from under duff in the evening and climb into the alfalfa canopy to feed. Some of the cutworms feed on new shoots under the duff, hold back regrowth, depleting starch reserves in the crowns and thereby weaken the plants. Weakened plants are more susceptible to disease. Permethrin, cyfluthrin and endosulfan are insecticides that control this pest, but larvae feeding under duff may escape insecticide treatments.

Weed Control: October is a good time to apply preemergent herbicides for winter annual grass control. Annual bluegrass in particular will germinate early in the season and is difficult to see and often missed by late applications. Other winter grasses like canarygrass or wildoat, require cooler soil temperatures to germinate. Remember that it is better to be a month early than a day late with preemergence treatments.

10 Year Summary (Aug. 27 - Sept. 9, 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.

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