Seedling production trends and fusiform rust control practices at southern nurseries, 1981-1991

Carey, W.A.; Kelley, W.D.

Seedling production trends and fusiform rust control practices at southern nurseries, 1981-1991

1993

Carey, W.A. | Kelley, W.D.

Southern pine seedling production and fusiform rust control practices within the Auburn University Southern Forest Nursery Management Cooperative were summarized from annual questionnaires since 1981 and projected for the South. Production peaked at approximately 1.6 billion seedlings in 1987 and 1988 and declined about 31% to 1.1 billion seedlings in 1991. The systemic fungicide triadimefon (Bayleton) replaced contact fungicides for control of fusiform rust during this period. Before triadimefon, the average percentage of rust-infected seedlings for southern nurseries was estimated at 2.5% (Rowan 1977); after triadimefon the average rust incidence has been only 0.2%. Sowing and harvest dates have not changed since 1981 and loblolly (Pinus taeda) and slash pines (P. elliotii) continue to account for 75% and 20% of southern seedling production, respectively. Reducing the rust infection percentage from 2.5% to 0.2% decreases by approximately 30 million the number of infected seedlings annually.

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