Cyproconazole for Control of Fusiform Rust on Loblolly Pine Seedlings

The efficacy of cyproconazole seed treatments and foliar sprays for control of fusiform rust on loblolly pine seedlings was evaluated in greenhouse and nursery trials. At the nursery, the percentage of untreated seedlings that were galled at lifting was high (54%). No seedlings receiving cyproconazole at the lowest dosage foliar spray (4 sprays at 123.25 g ai/ha/application ) without the seed treatment, and only 0.1% of seedlings receiving only the seed treatment (1.25 g ai/kg seed), were galled Laboratory inoculations indicated that seed treatments with cyproconazole at 1.25 and 2.5 g ai/kg seed were effective for at least 20 and 30 days, respectively, and that foliar sprays of 185.0 or 246.5 g ai/ha were effective for 14 but not 21 days. Eleven months after sowing, mycorrhizal development in the nursery was similar among seedlings receiving approximately equal dosages of either cyproconazole or triadimefon. Seedling growth was not significantly different between control seedlings and those receiving the various dosages of cyproconazole. South J. Appl. For. 18(3): 101-104.