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

Production Update:

Rhizoctonia: Rhizoctonia solani is usually of minor importance in Arizona, but the fungus can cause severe stand loss in some situations. Rhizoctonia is very versatile and can cause decay of the roots, stem, and leaves as well as the crowns. Symptoms usually occur during the warmer part of the growing season. Circular, concave, black lesions can appear on taproots but are not always seen in Arizona. Crown decay appears as dark, rotted areas within the crown tissue. The fungus can also girdle the stem near the soil line. The disease can cause circular lesions on the leaves. Control measures include resistant varieties, proper land leveling, and avoiding over-irrigation. No effective chemical control measures exist for rhizoctonia.

Insect Management: Egrets, Ibis, gulls, and redwing black birds are commonly seen in alfalfa fields. Birds are important predators of various insect pests in alfalfa including the very damaging granulate cutworm. Egrets, Ibis and gulls are often seen at the leading edge of irrigation water eating crickets and worms forced to move or drown. These birds feed during the day and roost at night. Therefore, they only eat the cutworms in lands where water is run during daylight hours. Black birds eat cutworms, other worm pests, and aphids on alfalfa stems.

Weed Control: Dripping herbicides into the water of flooded or furrow-irrigated established alfalfa can improve soil deposition and reduce crop injury. EPTAM is, however, the only herbicide registered for this type of application. There is interest in registering Trifluralin (Treflan) and Pendemethelin (Prowl) for this type of application in alfalfa, citrus and bermudagrass.

10 Year Summary (April 23 to May 6, 1993 - 2002):

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