Several improved irrigation scheduling methods are available to farmers to reduce the amount of water used while not reducing crop yield. Each scheduling method has its own advantages and disadvantages. Because of the disadvantages, farmers have been slow in adopting some of the newer irrigation scheduling methods. This study compares two improved scheduling methods, the neutron hydro probe and a simplified bookkeeping method using a personal computer, with the irrigation practices normally used by a farm manager to grow wheat. In addition to the traditional parameters of applied water and yield, the time and difficulty associated with each method were evaluated.

The relative ability of barley cultivars to perform outside the environment for which they were selected is not fully known. This study was initiated at Marana in 1985-86 to compare barley cultivars, which were adapted to different input levels, under a line-source sprinkler system that delivered a gradient of water. Higher than average rainfall in February and March provided ample moisture for crop growth, prevented very low water levels and led to the water gradient being applied late in the season when most of the cultivars were in the grain fill stage. We determined that cultivars bred for high level management (Gustoe and Barcott) performed best at the high water levels. Suitable cultivars for minimal water could not be determined since truly low water levels were never attained. Harvest index, the proportion of grain to total plant yield, was greatest for Gustoe at the high water level, but no differences were detected at the low water level. We suspect that one-irrigation barleys, bred to produce grain with a single preplant irrigation, effectively recover water with a deep root system and do not necessarily use less water than other barley cultivars.

The high yielding spring wheats grown in Arizona usually require applications of fertilizer nitrogen (N) to achieve optimum yields and acceptable quality. The University of Arizona's currently recommended procedure of preplant soil plus periodic stem tissue analysis for NO₃-N to predict the N needs of wheat is not widely used by Arizona growers. A nitrogen fertility trial was conducted at the Maricopa Agricultural Center during the 1985-86 crop year to evaluate the accuracy and practicality of the currently recommended procedure for predicting the optimum N rate for 'Aldura' durum wheat grown on a sandy soil low in residual N. Five rates of N from 0 to 500 lbs N/a were applied in four split applications. Three additional N treatments were made using equivalent amounts of three different N sources (urea, ammonium nitrate, and calcium nitrate) as indicated by the current UA procedure. Maximum grain yields of over 6500 lbs/a and protein levels above 13% were attained with the application of 215 to 250 lbs Nia. The amount of N predicted by the UA procedure (215 lbs N/a) did attain maximum grain yield and resulted in the most favorable adjusted economic return of all the fertilizer treatments used in the trial. Though additional work is needed, the stem NO₃-N tissue test was practical to use and proved quite accurate in predicting the N needs of durum wheat.

No description available.

On farm variety demonstrations are conducted by the Cooperative Extension Service to demonstrate the commercial potential of new and established varieties of wheat and barley when grown under various environmental and management conditions. As part of an ongoing variety demonstration program conducted in Yuma County, Arizona for the past 20 years, this study was conducted at TLM Farms on the south Yuma Mesa on extremely coarse-textured sandy soils under sprinkler irrigation. Five hard red spring wheat, six durum and four barley varieties were evaluated under TLM Farms management using 13 ft x 275 ft randomized plots with four replications. Statistically significant yield differences were measured that suggest, when compared to previous and other studies, that variety performance on coarse textured, sprinkler-irrigated soils is different than on finer textured flood-irrigated soils.

No description available.

A wheat and barley demonstration on the Bruce Church Farm, Poston, Arizona, harvested June 5, 1986, gave crop and variety performance differences under grower management conditions. The top yielding barley variety was Westbred Gustoe, 6190 lbs /acre. The leading durum varieties were Turbo and Yavaros, 7280 and 7220 lbs/acre, respectively. Durum Wheat Westbred 881 was highest in protein (15.6 %) and lowest in percentage of yellowberry. In the bread wheat varieties, yields ranged from 6740 to 6570 lbs per acre. Varieties tested were Yecora Rojo, Probred, Probrand 775, and Westbred 911, with no significant differences in yield between varieties. Yecora Rojo was highest in protein (15.8 %). While these are the results of one year, continued testing over several years is necessary to assess variety performance under grower management conditions.

No description available.

No description available.

No description available.