The effect of spacing and high planting density on yield of Eucalyptus globulus

Abstract

Production and marketing of Eucalyptus wood products play a significant poverty alleviation role; as a source of regular income and construction materials in turn improving the livelihoods of the rural community in Ethiopia. The study was conducted in Sidama region (Gorche district), South Central Ethiopia. The aim of study was to see the effect of spacing regimes (selected from the most common spacing practices in community) on yield of Eucalyptus globulus woodlots. Twenty five sample household’s woodlot from each spacing regime with a total of 100 woodlot plantations were sampled from two kebeles. Measurements of all DBH and height of standing E. globulus woodlot tree were made. Yield was significantly affected by the initial spacing regimes. With decreasing spacing, mean volume per tree was decreasing while volume per hectare was increasing. Within  1m x 0.75m, 0.75m x 0.5m, 0.5 x 0.5m and 0.5m x 0.25m spacing regimes,  0.031, 0.024, 0.0185 and 0.0116 m3/tree and 407.75, 637.82, 737.35 and 930.07m3/ ha mean volume of woodlot respectively were recorded. A one-way ANOVA revealed that there were a significant difference within; Volume, DBH and height of all spacing regimes. Local construction material /Seregela, Kuami, Weraji, Korkoro mager were the most common assortment poles depending on diameter and height. The study further revealed that highest number of biggest sized diameter construction pole were found from lower density planting, (1m x 0.75m) and the highest number of construction pole assortment were found from closer spacing (0.5m x 0.25m). In conclusion, spacing regimes had seriously affected yield of E. globulus woodlots. Finally, woodlot growers’ preference for different spacing regimes primarily depends on obtaining better final yield. And 1m x 0.7m and 0.75m x 0.5m spacing was found better in terms of providing proportional pole sizes of each assortment types