Casuarina introduction trials at Yuanmou hot dry river valley.
To rich tree genetic resources in hot dry river valley region, the nine species (Casuarina equisetifolia, Casuarina cunninghamiana, Casuarina glauca, Allocasuarina decaisneana, Casuarina obesa, Allocasuarina littoralis, Allocasuarina verticillata, Allocasuarina nana and Allocasuarina distyla) and one clone of Casuarina equisetifolia (Clone A8) were introduced to Yuanmou county, Yunnan province, China in 2003. The two field trials were established on 8 July 2007, the Casuarina introduction trial with six Casuarina species and one clone A8, and the inoculation Frankia trial for Casuarina cunninghamiana with four Frankia inoculation treatments and one control. A complete randomized block design was employed in the two trials, respectively, with four replicates and 30 trees per seedlot in the introduction trial, and four replicates and 20 trees per Frankia treatment in the inoculating Frankia trial. At one and two years after planting, tree heights and survival percentages of Casuarina were recorded for the two field trials. The results showed that Casuarina equisetifolia, C. cunninghamiana and C. obesa gained the best height growth, and C. glauca presented poorest height growth in the six species and one clone in the field trials. Casuarina equisetifolia could be applied to hot-dry valley for further extensive use according to the field experimental results. Based on the experimental results, C. cunninghamiana inoculated with some Frankia isolates showed very significant differences in tree height.