Insect Control on Flue-Cured Tobacco, 1979

Abstract

Abstract ‘MeNair 944’ flue-cured tobacco was transplanted in a fine sandy loam soil at the Southern Piedmont Center near Blackstone, Virginia on May 21. Spacing was 20 in between plants within the row and 4 ft between rows. Treatment plots, 2 rows x 40 ft and bordered on each side by 2 untreated rows, were established in a randomized complete block design replicated 3 times. Blocks were separated by 5 and 12 ft alleys. Sprays were applied on July 3 with a CO2-powered back-pack sprayer delivering 25 gal/acre at 60 psi through a single solid cone nozzle/row. Ambient temperature at the time of application ranged from 80 to 84°F. Wind speed was less than 5 mph. The only precipitation to fall during the test period was .15 in on July 4. The first row of each plot was artificially infested with 3 1st instar tobacco hornworm larvae/plant on June 30, while the second row were infested with one 2- to 3-day old tobacco budworm larvae/plant. Pretreatment tobacco hornworm (3rd instar and larger) and green peach aphid counts were made on July 3, while post-treatment green peach aphid, tobacco budworm, and tobacco hornworm counts were made at 3, 7, and 14 days after application. Artificially infested tobacco rows were examined for hornworms and budworms while aphids were counted or estimated on the upper half of 10 plants/plot. Green peach aphid counts were converted to LOG10+ 1 for statistical analysis.