Growth rates Variability in Eucalyptus Hybrid with respect to Site, Ro tation, Coppice Stand in relation to Original Stand

Abstract

The importance of Eucalyptus as the raw material source of paper and pulpwood industries needs no elabora tion. Thus this paper elicits information on extent of variability, effect of stand age, order of coppice sprouts relative to the original tree and number of coppice sprouts per stool on mophometric traits of E. tereticornis. The study conducted at two even aged plantations at Pudukkottai (10°1¢ N; 77° 5¢ E; 140 msl; 1000 mm; pH 5.3) and Coimbatore (11° N; 67° 5¢ E; 400 msl; 750 mm; pH 6.7) in Tamil Nadu revealed variability from 23.9 to 33.5 % in stem volume. Other parameters viz. merchantable height and bark proportion had significant variation with site. Age also affect growth rates and specific gravity was the highest in seven year plantation in comparison with three-year stand, while plantations of other ages showed parity. First coppice stand was equally comparable with that of first cutting (original stand) in terms of stem volume production while it recorded a reduction of 18 % in second coppice stand. While number of coppice shoots had no bearing on either dbh or merchantable height, it had significant influence on volume production; yield under two shoots per stump was exactly twice as much as that under one shoot per stump; that of three shoots was nearly two and half times as much.