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

Production Update:

PDF version, 59KB

Phosphorus fertilizer: In a 3-year study conducted at Maricopa (PDF file, 26KB), surface-applied 11-52-0 and water-run 10-34-0 were equally effective in increasing alfalfa yield. The fertilizer was applied annually in December. These results demonstrate that the alfalfa plant is capable of utilizing P from surface-applied fertilizer that is not mechanically incorporated. Most of the P fertilizer remained in the surface 3 inches of soil whether or not it was surface-applied or water-run.

Insect Management: [note - all picture links below will take you to other sites, hit your "back" button to return to this page] The blue alfalfa, pea aphid (PDF file, 85 KB) (picture, blue aphid) (picture, pea aphid) and cowpea aphid (picture) populations are being kept in check by predators and parasites in alfalfa fields this spring. Lady beetles observed feeding on aphids include seven spotted lady beetle, Coccinella septempunctata, (picture) the convergent lady beetle, Hippodamia convergens (adult picture) (larvae picture),and the ash gray lady beetle, Olla v-nigrum (picture). Green lacewing larvae (picture) have also been feeding on aphid species in alfalfa. Parasitic wasps attaching aphids in alfalfa include Lysiphlebus sp. (picture) and Diaraetiella sp. Beneficial insects play an important role in alfalfa insect management and should be protected. Only treat pest species with an insecticide when they reach the treatment threshold and use insecticides that are least harmful to beneficial insects.

Weed Control: An alfalfa weed control field day is scheduled for Yuma and Erhenberg on Wednesday, April 3. It will be on Avenue 6 1/4 E and 32nd Street from 9:00 - 11:00 a.m. and in Ehrenberg from 2:00 - 4:00 p.m. across from the Rovey Equipment yard on Tsosie Road. Call the Extension office for details.

10 Year Summary (March 12 - March 25, 1993-2002):

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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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