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

Production Update:
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Summer Slump: is well-known by alfalfa growers as the decrease in yields that normally occurs each summer in Arizona. Yield decline with later harvests in the season occurs in most alfalfa-growing regions of the world. Factors responsible for summer decline may include temperature, day length, water stress, aging, and depletion of food reserves in the plant. The rate of maturation of the crop is probably a primary factor responsible for summer decline. In other words, the crop produces a seed head so fast that time is not available to accumulate yields similar to the spring. Summer slump can not be avoided in Arizona, but maintaining adequate soil moisture levels can slow yield decline. Also, increasing the cutting interval for one harvest during the late summer is recommended to promote the health of the stand during this stressful time of year.
 

Insect Management:Witches'-broom disease has only been of minor importance in the western United States, but is now present in some low desert alfalfa fields. The disease was long considered to be a leafhopper-transmitted virus, but now is known to be caused by a mycoplasmalike microorganism. A vector of alfalfa witches'-broom disease in the western United States is a leafhopper, Scaphytopius acutus. It is not known if this leaf hopper or another leaf hopper is responsible for the current disease symptoms. Symptoms of the disease include excessive development of short, spindly shoots from the crown and axillary buds along the stem. Spraying to control vector of the disease is out of the question at this time as the epidemiology of the disease has not been studied in the low desert.
 

Weed Control: EPTAM and Balan are the only herbicides registered for preplant use in alfalfa. Both can reduce seedling numbers and slow stand establishment. These are the only options, however, for growers wanting to keep weeds from coming up with seedling alfalfa. 
 
 

Market Summary	High	Low	Average	Off grade
Past 2 Weeks ( July 30 to August12, 2001)	90	70	80	60-70
Last Year (July 30 to August 12, 2000)	65	60	63	50-60

 

10 Year Summary (July 30 to August 12, 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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