Investigations were conducted in 1966 and 1967 at Tucson, Ariz., to study some effects of soil‐moisture stress, at three different stages of development (jointing, flowering, and dough) on the growth and grain yield of spring wheat (Triticum aestivum L. em Thell.) planted in December. A critical period in the growth of wheat was the jointing stage for moisture. Stressing wheat for water at jointing resulted in fewer days from planting to flowering, shorter plants, more lodging, lower grain yield, lower grain volume‐weight, fewer heads per unit area, and fewer seeds per head. Soil‐moisture stress at any stage of growth decreased grain yield. When wheat was stressed at jointing, reduced grain yield resulted from fewer heads per unit area and fewer seeds per head. However, when moisture stress occurred at the flowering and dough stages, lower grain yields were caused by lighter seed‐weight. Stress at the flowering and dough stages also hastened maturity.

Synopsis The grain yield, test weight, and weight per 1,000 seeds were decreased as a result of 90° lodging treatments of irrigated spring barley grown as a winter annual. Lodging treatments of 45° and 90° resulted in a decrease in the percentage of plump kernels and the grain color score. The percentage of thin kernels was increased as a result of 90° lodging treatments.

In 1974 and 1975, experiments were conducted near Buckeye, Arizona to study the influence of municipal waste water on the growth and yield of cotton (Gossypium hirsutum L.). Two sources of irrigation water were used: (i) pump water from local wells (control treatment) and (ii) municipal waste water and pump water in a 50:50 mixture.Cotton irrigated with the waste water and pump water mixture grew taller with more vegetative growth than did cotton that was irrigated with pump water alone. When cotton was irrigated with the waste water and pump water mixture, the yields of seed cotton and lint cotton were higher than the yields from cotton irrigated with pump water. Cotton irrigated with waste water and pump water produced lint of the same quality as did cotton irrigated with only pump water.Municipal waste water can be used effectively as a source of irrigation water and plant nutrients in the commercial production of cotton in Arizona and, possibly, in similar environments throughout the world. When municipal waste water is mixed with pump water that is high in total soluble salts, the salt content of the mixture is lowered and the quality of the irrigation water in the study area is improved.

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