PROVENANCE VARIATION IN PINUS-MURICATA IN SOUTH-AFRICA

Genetic variation in height, diameter at breast height, stemform, crownform, resistance to Pineus pini and form defects, between six provenances of the "blue" and one of the "green" strain of Pinus muricata D. DON, have been analysed at the age of four and eight years, in four trials established in the constant, winter and summer rainfall areas of South Africa. The Sonoma provenance of the "green" strain was the best provenance in growth and stemform, often identified by subset selection as the sole outstanding treatment. Strong clinal decline at all sites in growth and stemform with latitude or longitude of place of origin indicated that the most southerly populations of the "green" strain would be optimum for South Africa. Altitude of place of origin had no influence on provenance variation. There was no evidence of provenance variation in rate of defects. There was little or no evidence of provenance-by-site interaction for any of the traits studied. Selection of the best provenance was possible at age four years. Use of the Sonoma provenance at all sites suitable for Bishop pine was recommended as well as further testing of provenances of the "green" strain. At four and eight years the growth rate of Bishop pine was inferior to that of Pinus radiata.