Alfalfa varieties differ in fall dormancy, defined asgrowth during the fall. Nondormant alfalfa varieties are usually planted in mild winter areas for their ability to grow in the fall. Nondormant, very nondormant, and extremely nondormant alfalfa varieties (fall dormancy class 8, 9, and 10) are adapted to elevations below 4000 feet in Arizona.
Recent outbreaks of cowpea aphid in alfalfa are more than a local phenomena. Large populations of cowpea aphids have been reported throughout Arizona. The reason behind these outbreaks are unknown. This article hopes to bring some insight by discussing the cowpea aphid, the damage it causes, and suggestions on controlling it.
This article contains a chart of non dormant alfalfa varieties for Arizona. Suggestions for determining an appropriate fall dormancy class, identifying potential pest problems, yield, and salt tolerance are all discussed.
Genetic Diversity and Fungicide Sensitivity of Phymatotrichopsis omnivora
Cotton root rot, caused by Phymatotrichopsis omnivora, is the most destructive disease of dicotyledonous plants in Arizona. There are no known reliable control methods for this disease, and the difficulty in its management is most often directed at its survival deep in soils and its wide host range. Genetic diversity in P. omnivora and its potential role in disease are unknown. Isolating the fungus and reproducing the disease in the greenhouse or laboratory are problematic, making it difficult to assess the efficacy of potential treatments.
Methods of Measuring for Irrigation Scheduling - When
Proper irrigation management requires that growers assess their irrigation needs by taking measurements of various physical parameters. Some use sophisticated equipment while others use tried and true common sense approaches. Whichever method used, each has merits and limitations. In developing any irrigation management strategy, two questions are common: “When do I irrigate?” and “How much do I apply?” This bulletin deals with the WHEN.
Alfalfa is an important crop grown in Arizona with approximately 250,000 acres in production in 2011 and 2012 and 260,000 acres for 2013. As alfalfa stands age, they can thing and decline in plant density. This article takes a look at renovating alfalfa stands in Arizona.
“Summer slump” is a decline in growth of alfalfa usually beginning in July in areas where maximum daily temperature exceeds 100 °F, such as the low elevation deserts of Southwestern U.S. This article discusses some of the causes behind this and potential impacts.
Stink bugs in cotton, alfalfa, and other Arizona crops
In Arizona, we have many species of stink bugs; the species pictured above are encountered in cotton, alfalfa, and other crops. Some are occasional or potential pests of cotton. In the article the Brown Stink Bug (BSB), Eushistus servus, is discussed which has been a pest of cotton, especially in the past few years.
Insect Management on Desert Produce Crops: Western Flower Thrips 2013
Western flower thrips are major pests to lettuces, cabbage, and spinach because of the damage they cause to these plants. This article describes their development, Economic Damage, and suggestions for their management.
Determining the Amount of Irrigation Water Applied to a Field
Critical to any irrigation management approach is an accurate estimate of the amount of water applied to a field. Estimating the amount of water applied to a field or to a set is fairly easy for surface systems.
Alfalfa Weed Control in the Low Deserts of Arizona
Alfalfa is a vigorous crop that is very competitive with weeds. However, chemical weed control is often necessary even in well managed alfalfa since the marketplace has a low tolerance for weeds in alfalfa hay.
Due to worldwide shortages of non-dormant alfalfa seed, production opportunities and acreage have increased recently in central Arizona. This article gives some suggestions regarding growing alfalfa for seed in Arizona.
Beet armyworm (Spodoptera exigua) caterpillars are smooth skinned with few or no hairs on the body, may be olive green to almost black in color down the middle of the back, and have a yellow stripe on each side of the body. This publication details the Beet Armyworm. It's description, biology, damages it causes, and methods of controlling it are discussed.
The first sign of a potential alfalfa caterpillar (Colias eurytheme) outbreak is the influx of large numbers of yellow or white butterflies in late spring or early summer. This article discusses their biology, the damages they cause, types of control, and when to treat for them.
Aphids feed in groups, often on the growing tips of plants. This article describes the complex of Aphids that can be found on alfalfa and discusses damages, monitoring, control, and when to treat for them.
Establishing irrigated pasture at 4,000- to 6,000-foot elevations in Arizona
Authors: Deborah Young, Bill Frost, Mike Schneider
Irrigated pasture can provide forage for livestock, be useful during breeding and calving time, serve as an exercise area for horses, and conserve and improve soil and provide an alternative to rangeland. This article discussing establishing a pasture at elevations in Arizona between 4,000 and 6,000 feet.
Authors: Thomas A. Doerge, Robert L. Roth, Bryant R. Gardner
Nitrogen applications are rarely needed in alfalfa production in Arizona. The primary problems with nitrogen applications to alfalfa are stimulation of weed growth, reduced nodulation, and reduced effectiveness of nodules in "fixing" of nitrogen.
Diseases and Nutritional Disorders of Alfalfa in Arizona
Authors: Richard B. Hine, Michael J. Ottman, and Thomas A. Doerge
Alfalfa is currently grown on approximately 20 percent of the total irrigated crop land in Arizona. This article lists the diseases and nutritional disorders of Alfalfa and gives a lengthy description of each of them.
Forage stands are maintained longer when pastures are properly managed. When a mixture is used, try to maintain each species in its original proportion. This article gives suggestions for maintaining pastures.