3. Results
3.1. Weather conditions and drought type in experiment A
Weekly mean maximum and minimum air temperature gradually declined from seeding to about 8 weeks after seeding and then gradually increased until the end of experimental period (Fig. 1). Mean temperatures between seeding and 65 DAS was below 25 °C. These relatively low temperatures after seeding slowed seedling emergence and plant growth. During the drought stress period (50–122 DAS), mean temperature increased slowly from about 25 to 29 °C Pan evaporation averaged 37 mm per week during the first 13 weeks after seeding and increased to 45 mm per week in the last 6 weeks of the stress period. There was a total of 10 mm rainfall at 6 and 11 DAW but it had little effect on the development of drought stress. However, it was recognised that there was some lateral water movement in the field, which contributed to the slow development of drought stress in the experiment.