Fusiform Rust Resistance of Select Loblolly Pine Seedlots in the Laboratory, Nursery, and Field

Abstract

Abstract Twenty-three seedlots exhibited consistency in relative resistance to fusiform rust whether testing was in the Resistance Screening Center, nursery, or in long-term field tests. Results indicate that family screening for rust resistance can be conducted on one-year-old trees at less cost, and perhaps more accurately, than that of long-term field testing. In a nursery where some seedlings were left unprotected from infection while others were chemically protected, both lots were culled to produce rust-free seedlings for field planting. After four years both protected and unprotected trees had the same level of infection. As nursery screening of moderately infected trees does not significantly increase field resistance of the remaining noninfected trees, we suggest that nursery seedlings be chemically protected.