Effects of coppicing on vegetative growth and yield of coppice in three eucalyptus species, damaged by frost (Case study: Wastewater treatment station of Yazd city)

Reaction vegetative growth and yield of 7-year-old trees of three eucalyptus species (Eucalyptus camaldulensis, E. microtheca and E. sargentii) to coppicing and coppice production which damaged by frost, were studied. Trees had been planted under Yazd climate conditions and they have been irrigating with wastewater. The species were used in this experiment; planted in 2007 for compatibility testing in a randomized complete block design with three replications and 36 plants per each block. All trees were damaged by frost in 2013. In the spring, trees were cut by a chainsaw at a height of 15 cm from the soil surface. After three months of coppice growth, the number of coppices were reduced to three in each trunk. After three years, results of coppicing and thinning of coppices were evaluated on six plants in each block that they were selected randomly. For evaluating production ability of coppice on each trunk, all plants in each block were investigated. The results showed that between the coppices of species were significant difference (P <001) in the number of basis after coppicing. E. microtheca had the most of basis with 80.26 percentages. Diameter equations and height of coppices in all of species had significant difference (P<001). Coppices canopy diameter, surface canopy, volume and percentage canopy had significant difference (P<05). E. camaldulensis coppices had better characteristics than other species. In some cases, such as coppices canopy diameter and canopy surface were not significant difference between E. camaldulensis and E. sargentii.