SURVIVAL, GROWTH, YIELD AND WOOD DENSITY OF <em>PINUS</em> <em>PATULA</em> LAND RACES/PROVENANCES AT SAO HILL AND SHUME FOREST PROJECTS, TANZANIA

Abstract

The performance of five Pinus patula land races at Kihanga Arboretum, Sao Hill (Sao Hill Forest Project) and two Mexican provenances and eight land races at Sungwi, Lushoto (Shume Forest Project), Tanzania were compared in terms of survival, growth, yield, stem form and wood basic density. Final assessment was done at Kihanga and Sungwi experiments at ages of 18.0 and 21.9 years respectively. The main results of the study were:
- The survival of all land races and/or provenances in the two sites was generally high (83.3 - 92.9%) but were not statistically significant (p > 0.05).
- At early ages: up to 5.3 years for the Kihanga experiment and up to 4.6 years for the Sungwi experiment, height growth revealed significant differences (p < 0.05).
- DBH growth showed significant differences (p<0.05) at age 7.6 years for the Kihanga experiment and 4.6 and 9.9 years for the Sungwi experiment.
- There was no significant difference (p > 0.05) in stem form between the land races/
provenances at Sungwi.
- For the Kihanga experiment the two Sao Hill land races had significantly higher basal area and standing volume at early ages only. At Sungwi, there were significant differences between provenances in terms of basal area at ages 4.6 and 21.9 years and standing volume at ages of 4.6, 9.9 and 21.9 years. The two Rhodesian land races and two Mexican provenances had the highest yield.
- Basic density ranged from 372 km m'3 for one Sao Hill land race at Kihanga to 499 kg m3 for the Kenya land race at Sungwi but there were no significant differences (p > 0.05) in wood basic density between land races/provenances at both sites. Overall, the Rhodesian land races and Mexican provenances performed better than the rest. It is recommended therefore that these land races/provenances be used as seed source for afforestation programme at Shume. The Kigogo land race is already in use. However, as a way of broadening the genetic base, the other provenances can also be used as seed source for afforestation at the respective sites.