Abstract
SYNOPSIS Seedlings raised from seed collected from 64 Pinus pinaster ortets and 20 P. radiata ortets which were free from Pineus pini in the plantations and seed orchards of the Southern Cape were infected with eggs of the pest. After three months the degree of infection on the seedlings was measured. The average family variation in resistance was poor for P. pinaster but strong for P. radiata. Some 11% of the 2 865 P. pinaster trees and 98% of the 1 056 P. radiata trees submitted to the test were free of the pest. Four families of P. pinaster warrant further investigation through controlled pollination, while a single cycle of selection in P. radiata appears sufficient to obtain a resistant population. The rooting ability of the resistant seedlings will be measured and cuttings propagated for further field trials with clonal material. It is recommended that work with P. pinaster be greatly reduced in favour of increased work on P. radiata D. Don.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
