Temperature and solar radiation on Australian cedar seedlings production

The aim of this study was to estimate the base temperature for leaf emission and determine the radiation use efficiency of Australian cedar seedlings. Two plants density were used in the tray, 100 and 50%, denominated high and medium density; the high density presented 494 plants m(-2) and the medium 247 plants m(-2). Base-temperature for leaf emission, phyllochron, leaf area index, total accumulated dry matter, interception of global radiation, extinction coefficient and radiation use efficiency were evaluated. The results indicated that the base temperature for leaf emission under high and medium density of seedlings was 6.6 degrees C and 7.7 degrees C, respectively, while the radiation use efficiency for high and medium seedling density was 1.42 and 1.11 g MJ(-1), respectively. For the production of Australian cedar seedlings, the use of high density of seedlings in the tray should be prioritized because they present a higher leaf emission, leaf area index and radiation use efficiency, optimizing the nursery use.