Yuma County Office
2200 W. 28^th Street, Ste. 102
Yuma, AZ 85364
(520) 726-3904
(520) 726-8472 FAX

Production Update:
PDF version, 17KB

Barn Fires: Baled hay can catch fire if stored between 30 to 40% moisture due to heat produced by microorganisms and plant respiration. Hay baled at safe moisture levels of 20% or less may rise to a temperature of 130 to 140° F for a few days before gradually cooling off. If hay temperature rises above 140° F, temperature should be monitored every few hours. At temperatures between 150 and 160° F, it is time to prepare to remove hot hay from the stack or secure a source of water in case temperature continues to rise. It would be wise to call the fire department when hay temperature exceeds 180° F. When temperature reaches 200° F, bales may burst into flames when removed from the stack if not wetted.

Insect Management: Spider mites do not often cause wide spread damage to alfalfa grown for hay and damage may be associated with water stress. Spider mites feed by inserting long needle-like mouth parts into leaves removing plant sap causing a yellow stippling on leaves and leaves are covered with webbing. Severe feeding causes necrosis, leaves turn brown, become dry and drop from the plant. Infestations are usually confined to the lower leaves so damage starts in the lower plant canopy moving upward. Feeding damage reduces yield, quality and retards regrowth. Spider Mite Species in Western Arizona & Southern California include: carmine spider mite (T. cnnabarinus Boisdival); desert spider mite (T. desortorum Banks); strawberry mite (T. turkestani Ugarov & Nikolski); and twospotted spider mite (Tetranychus urticae Koch). Avoid using pyrethroid insecticides for alfalfa pest control; they can flare spider mite infestations. Minimizing crop stress through improved irrigation; when fields are watered, infestations often clears up in a few days. When severe infestations occur, sulfur may be used to suppress the populations.

Weed Control: Swine cress (Coronopus didymus) was found this year in an alfalfa field on the south Yuma Mesa. This is a winter annual in the mustard family that is a common urban weed but can be a problem in alfalfa as well. The more difficult to control and invasive, coronopus squamatus, is more vigorous and invasive and is found in the Imperial Valley but has not, to our knowledge, been found in Yuma. Both are controlled with Pursuit while many other herbicides are weak or ineffective on these weeds.

10 Year Summary (June 4, to June 17, 1992-2001):

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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