Mist-Blower Applications for Control of Flower Thrips and Southern Cone Rust in a Slash Pine Seed Orchard12

Abstract

During 1967 and 1968, tests were conducted to determine if a flower thrips, Gnophothrips fuscus (Morgan), and southern cone rust, Cronartium strobilinum (Arthur) Hedgcock and Hahn, could be controlled with mist-blower applications of the fungicide ferbam combined with either malathion or heptachlor. Testing was done in a seed orchard of 8- and 9-year-old slash pine, Pinus elliottii Var. elliottii Engelmann, in northern Florida. Two applications of 0.25% heptachlor or 0.75% malathion effectively reduced thrips attacks on female strobili. Malathion was the most effective and reduced total thrips attacks by 75%, and thrips kill of strobili by more than 80%. Ferbam did not deter allacks by thrips. Ferbam protected artificially inoculated strobili from infection by C. strobilinum , but the feasibility of controlling southern cone rust with mist-blower applications of ferbam in seed orchards was not substantiated because of lack of natural infection. None of the treatments adversely affected total seed yields, full seed yields, or percentage full seed germination.