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Alfalfa seedlings were grown under saline conditions for six weeks and separated into two populations, based on height. Water potential was measured on roots, stems, leaves, and petioles of tall and short plants. Tall plants had a higher water potential for each plant part.

The handling of alfalfa and other crop seed may result in seed scarification. Scarification may not affect germination of alfalfa seed in a non - saline environment, but may decrease germination where farmer's fields are severely salt-stressed.

Twenty non - and very non - dominant alfalfa varieties were compared over three seasons. The top - yielding variety, Pioneer 5929, has maintained this position for the last three years. The yields decreased considerably from the previous year, however. Part of the loss can be attributed to the sacrifice of the first cutting because of damage by the Egyptian alfalfa weevil. Pioneer 5929 was the top -yielding variety during the entire trial, producing more than 30 tons per acre. Four other varieties produced more than 28 tons per acre: Ardiente by Agripro; Pierce by Northrup King, Palmer Special by the Palmer brothers of Graham county; and Safford 80 LH.

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An alfalfa decline problem has appeared recently in fields between Poston and Parker in La Paz County. Cercospora summer black stem and leaf spot, a fungal disease of alfalfa, has been associated with the decline problem. The efficacy of three fungicides were tested for control of the disease and the decline problem. Bravo, Kocide, and Spotless significantly reduced the severity of Cercospora summer black stem and leaf spot; however, significant increases in yield were not realized. Alfalfa decline in La Paz County may involve other factors in addition to plant disease.

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The stem nematode Ditylenchus dipsaci attacks non-dormant Arizona alfalfa in the desert valleys; damage occurs during the cooler months of fall and spring. Efforts to introduce and retain resistant alfalfa has had limited success. From October until temperatures decrease below 50 F., the nematode reproduces and feeds. In warmer years, damage may be sustained from October until spring temperatures exceed 85 F. Chemical control may be warranted during these periods of feeding activity. Field trials were established to determine the efficacy of pesticides registered for use in alfalfa. Temil; Vydate, Furdan, Disyston, Thimet and Dasanit applied either in fall or spring were effective in controlling populations when first detected following dormancy. The best control is obtained when pesticides are applied immediately after harvest and prior to irrigation. Yield increases up to 15-25% were obtained with decreased yields in non -treated controls of 40-80%. Stand decline was reduced as much as 50% when treatments were correctly applied.