Bibliography: leaves 213-245. Genetic control of tolerance to boron was investigated between a moderately tolerant variety, Halberd, a tolerant line G61450 and the moderately sensitive varieties Schomburgk and Condor.

Bibliography: leaves 213-245. / iv, 246, [59] leaves of plates : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Genetic control of tolerance to boron was investigated between a moderately tolerant variety, Halberd, a tolerant line G61450 and the moderately sensitive varieties Schomburgk and Condor. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1996

Bread wheat (Triticum aestivum L.) is one of the most important cereal crops grown in the world. It has great importance because it constitutes a major source of carbohydrate for more than one third of the world’s population (Budak et al., 2013). In the last three decades, drought conditions are becoming more widespread in wheat production areas including Europe, Australia and Asia, and it is considered a major cause of reduced wheat growth and productivity in most developing countries with semi-arid climates. Drought constitutes the most important threat for wheat production in Iraq and especially for the Kurdistan Regional Governate owing to the limited source of water during at least some part of the growing period. Because wheat is considered a staple food and has economic importance for the Kurdistan Regional Government research is needed to determine the production capacity of Iraqi wheat varieties under drought stress and the potential for the maximization of the drought tolerance response. The soil moisture holding capacity of the intended growing medium was measured gravimetrically in pots with and without wheat plants and correlated with the soil capacitance measured using a TDR Theta Probe (Delta-T Devices). This was used to determine the available water content of the soil (AWC) and to control and manage the watering regimes during drought studies. The results of a study of the response of different cultivars of Iraqi wheat (Triticum aestivum L.) to watering regimes of 70% and 50% showed that drought stress had a significant effect on the biomass and yield traits especially tiller number and stem bundle weight compared to normal conditions. The highest significant difference was observed for cv. Tamooz 2 in comparison to Adana 99, but there was a little difference between cvs. Rizgary and Sham 6. The effect of the exogenous application of salicylic acid (SA) and molybdenum (Mo) on drought tolerance of cvs. Tamooz 2 and Adana 99, showed that Tamooz 2 had higher values for growth characteristics and higher yield potential when sprayed with a lower concentration of SA (1.44 mM) under well-watered conditions in comparison with Adana 99. The effect of spraying variety Tamooz 2 with SA at different growth stages indicated that biomass production and yield components (the number of spikes/pot, grain dry weight and average 1000 grain dry weight) significantly increased at both stem+flower as well as leaf+stem+flower sprayings for plants subjected to drought. Also, SA treatments at stem extension and flowering had a positive effect on the up-regulation of the drought response gene CBF/DREB under drought stress conditions. These findings indicate that agronomic treatments with exogenous applications of salicylic acid and molybdenum could help to reduce the effects of drought in the field.

No description available.

No description available.

Nine varieties of barley were tested at the Safford Agricultural Center in response to growers' requests for high yielding barley varieties with the potential to mature more quickly than Gustoe. Gustoe was the top- yielding variety with 5,551 pounds per acre. A University of California variety was a close second but it has the same maturity as Gustoe. The varieties that mature more quickly, Barcott and Fiesta, yielded approximately 1,500 pounds fewer than Gustoe.

Eight barley varieties were tested in a replicated variety trial in northern Cochise county. These varieties varied from relatively early maturing varieties, such as Barcot4 to the longer maturing varieties, such as Gustoe. The medium -late variety, Northrup King 1558, was the top - yielding variety, with 7,185 pounds per acre. This exceeded the yield of the standard variety, Gustoe, by 15 percent, making NK 1558 a variety that should be looked at further. It will be marketed by Northrup King under the name Sunbar 458.

Ten varieties of oats were grown in a trial to test grain yield. Five of the varieties produced more than 4,000 pounds per acre; the top - yielding variety, Ogle, from Minnesota, produced 4,578 pounds per acre. Difficulties in establishing a perfect stand with the small plot grain drill would probably mean that a farmer could expect yields higher than these when using full -sized equipment. Considering the premium for oats, oats for grain could be a viable alternative crop.

Eleven oat varieties were tested for grain and forage yields at the Safford Agricultural Center. Cayuse, the predominant variety grown in the area was the top producer of total dry matter. Four other varieties had higher grain yields than Cayuse.

Variety mixtures may lessen competition among plants and reduce effects of stress particularly in environments where resources are limiting. Mixtures of four barley varieties were grown under low input conditions at the Maricopa Agricultural Center. The barley varieties seeded were Barcott, Solum, Solar, and an experimental low input line designated Entry 9. The highest yields were not obtained with mixtures in this experiment, but rather when the varieties were grown alone. Barcott and Entry 9 decreased yield when part of the mixture more than Solum or Solar. When Solum was grown in a mixture rather than alone, test weight and lodging were improved, but yield was decreased.