Variation in plantations of P̲i̲ṉu̲s̲ c̲a̲ṟi̲ḇe̲a̲ var. ẖo̲ṉḏu̲ṟe̲ṉs̲i̲s̲ barr. and golf. in Southern Monagas, Venezuela

Twelve seed sources of three P. Caribaea varieties were planted in a randomized block design with 36 trees per plot. Variation in stem growth and branch characteristics among the seven sources of P. Caribaea var. hondurensis was small. Significant variation was observed in wood properties; Guatemalan provenances had lower specific gravity than British Honduran and Nicaraguan provenances. The greatest number of defective stems was found in variety hondurensis. This variety was significantly different from the other two P. caribaea varieties and P. Oocarpa

External needle morphology and cortical monoterpene composition verified the identity of the three P. Caribaea varieties. These varieties were separated by different amounts of limonene and B-phellandrene. Some discrimination within sources of P. Caribaea var. hondurensis also was made by using monoterpene variation.

One-hundred twenty circular plots of 1/10 ha. were sampled in P. Caribaea var. hondurensis. Significant variation due to site conditions was observed in height and diameter, while stocking had large influence on volume per ha. All the plantations evaluated had poor stem form, with high incidence of foxtailed, crooked and forked trees.

Extracted wood specific gravity ranged from 0.35 in the youngest plantations to 0.39 in the oldest. Large variation was observed among trees in all plantations, suggesting that this trait may be under strong genetic control in P. Caribaea var. hondurensis. Extractives content ranged between 0.014 and 0.018 g/cm³ among plantations.

The cortical monoterpenes analysis suggest that seedlings were produced from different seed sources. Trees of the other two P. Caribaea varieties and P. Oocarpa were possibly planted in addition to P. Caribaea var. hondurensis. This conclusion is based on the larger phenotypic variation in monoterpene composition in commercial plantations than in the provenance test.