SURVIVAL, GROWTH, YIELD AND WOOD DENSITY OF THREE <em>PINUS</em> <em>PATULA</em> PROVENANCES AT LUSHOTO, TANZANIA

Abstract

A Pinus patula provenance trial containing seeds from Rhodesia (now Zimbabwe) and Tanzania (Kigogo in Mufindi and Old Moshi in Moshi) was established at Lushoto, Tanzania in 1968 to determine provenance differences in survival, growth, yield and wood density. Data on these parameters were collected from the experimental plots in 1990 at the age of 22 years. The main results were:

- After one thinning, stocking was 54% for the Rhodesia and Kigogo provenances
and 51% for the Old Moshi provenance. Before thinning, which was done at
11 y, the survivals were 91.3% for the Rhodesia, 96.7% for Kigogo and 94.2% for
the Old Moshi provenances respectively.
- Mean height ranged from 23.1 to 23.9 m. The Rhodesia provenance had the
highest mean height value.
- Diameter at breast height (DBH) ranged from- 22.5 to 23.3 cm, the Rhodesia
provenance again having the largest DBH.
- Standing basal area ranged from 34.26 to 38.3 m² ha^-1 with the Rhodesia
provenance having the highest mean basal area.
- Total volume production ranged from 452.6 to 516.6 m³ ha^-1 with the Rhodesia
provenance having the highest total volume production.
- Basic density ranged from 389 to 423 kg m³ with Old Moshi provenance having
the highest basic density value.

Statistical analysis, however, showed no significant differences between provenances in all the parameters assessed (p = 0.05). It is recommended that since the Kigogo and Old Moshi provenances are already being used in afforestation programmes, the Rhodesia provenance be also used as a seed source to broaden the genetic base.