Bibliography: leaves: 210-230.

Bibliography: leaves: 210-230. / xx, 230 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1995?

No description available.

The protein concentration of cereal grains is low and the production of cereal crops with increased grain protein concentrations is desirable. This work investigates the physiological aspects of protein accumulation potential in barley grain. A recently developed perfusion system was used in four experiments conducted in 1993 and 1994. In the field experiment, plants were allowed to take up urea at 15 or 30 mM N, or ethephon at 15 $ mu$ M. Abscisic acid and 2,4-D decreased total seed weight spike$ sp{-1}$. Gibberellic acid and 2,4-D increased seed protein concentration and content, while ABA decreased both of these. Kinetin and abscisic acid treatments resulted in the highest and lowest levels, respectively for flag leaf photosynthesis, stomatal conductance, transpiration and intercellular CO$ sb2$ concentration. Both protein content spike$ sp{-1}$ and seed protein concentration were elevated in plants fertilized with 10.7 mM N via the soil and plants perfused with 30 mM N via the peduncle. Plants receiving treatments of 10.7 mM N from the soil and mixture of 30 mM N and GA$ sb3$ or 2,4-D through the peduncle had increased protein content seed$ sp{-1}$, and the highest seed weight spike$ sp{-1}$, respectively. Peduncle perfusion with 30 mM N increased spike protein concentration and content and grain protein concentration without affecting seed weight spike$ sp{-1}$. Grain protein concentration was increased by peduncle perfusion with ethephon. The perfusion technique worked well under field conditions. (Abstract shortened by UMI.)

A study was conducted for two growing seasons in northeastern Syria to evaluate the effect of N and P fertilizers and previous crops--i.e. vetch (Vicia sativa L.), barley (Hordeum vulgare L. cv. Beecher) or fallow--on water consumption, development, growth and yields of barley in a semi-arid, Mediterranean-type climate. / The two seasons contrasted in rainfall and temperature which affected soil N, water use and yields. Fertilizer addition and residual P were the major determinants in barley yield increases. Rotation effects were significant only when fertilizers were added. Fallowing was an inefficient way of storing water, but stored water was used most efficiently by subsequent barley crops when fertilized. / Fertilizers did not increase total evapotranspiration. Water use efficiency was related to dry matter production at stem elongation (DMse). Grain weight was a stable component of grain yields. Grain number was related to crop growth rates during the three week pre-anthesis period and to DMse, in turn affected by temperature, nutrient and moisture conditions. / Vetch yields were in the order of 2.5 t.ha$ sp{-1}$ in the wetter season (1982/83). / Results showed that substantial barley yield increases can be obtained with innovative crop rotations and appropriate use of fertilizers in semi-arid environments.

No description available.

No description available.

An experiment was conducted at the Eastern Virginia Research Station, Warsaw, comparing the effects of fall applications of nitrogen (N), (0, 28, 56 kg/ha) from fish-solubles (FS) and spring applications of N (0, 56 kg/ha) from NH₄NO₃ on yield and components of yield of four cultivars each of barley (Hordeum vulgare) and wheat (Triticum aestivum). Both barley and wheat expressed significant yield responses to FS. The NH₄NO₃ application increased yields in both crops, although the increase in wheat was not statistically significant. Interactions between the barley cultivars and N source or rates were nonexistent; however cultivar yield and thousand kernel weight (Mkw) did express interactions with the nitrogen levels and sources in wheat. Cultivars of both crops displayed significant differences for almost every analyzed trait. Both crops responded similarly in the effect of N rates and sources on components of yield, with the greatest response being an increase in spikes/61 cm as the N rates increase. In barley, the increasing rates of N caused a slight increase in kernels/spike, while there was very little effect in wheat. In wheat, the spring application of NH₄NO₃ decreased Mkw, but there was no such effect in barley. Samples of the ten best heads taken from the plots provided useful estimates of kernels/spike in wheat, Mkw in both crops, and of cultivar yield in barley. / Master of Science