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

Production Update:

Cutting Height: The optimum cutting height for alfalfa varies from about 2 to 4 inches. As cutting height is increased, more growth occurs from buds originating on the stems and less from the crown. Stem buds are less productive than crown buds, so increasing cutting height often reduces yields. However, crown bud development is suppressed if alfalfa is cut at early stages of growth or on a frequent basis. In these cases, lack of crown bud development can be compensated for somewhat by increasing the cutting height and encouraging more regrowth from the stems. A cutting height of 3 inches resulted in prolonged stand life compared to a 1 inch cutting height in an Arizona study. Crop quality can be manipulated with cutting height since the lower part of the plant is poorer in quality than the top.

Insect Management: Threecornered alfalfa hopper, Spissistilus festimus, is a treehopper commonly found in alfalfa. Adults and nymphs suck plant sap by puncturing stems. Female treehoppers girdle stems by depositing eggs. The stem and leaves turn red, purple or yellow above the girdle. Adults are light-green, thick-bodied, triangular insects about 1/4 inch long and readily fly when disturbed. Nymphs are grayish-white, soft bodied, with saw-toothed spines on their backs. Nymphs are confined to the lower portions of the plant and may not be picked up in a sweep net. Threecornered alfalfa hoppers rarely cause economic damage. Definitive monitoring and treatment guidelines have not been developed because threecornered alfalfa hoppers are a sporadic problem in alfalfa.

Weed Control: Sandbur, both field and southern, can be controlled with Poast and Select when it is no larger than 1 or 2 leaves. If it gets much larger than this or if it is coming back from established plants, it will tolerate both of these herbicides.

10 Year Summary (April 9 - April 22, 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.