Control of the Sweet Potato Whitefly on Poinsettia Under Glasshouse Conditions, Fall 1988

Abstract

Abstract Poinsettias (Annette Hegg cv. 'Brilliant Diamond) were obtained as rooted cuttings and potted in 6 inch pots in a greenhouse and allowed 4 wk growth before use. At such time, 10 whiteflies were confined to one expanded leaf on each of 60 plants for a 48 h period by clip cages. Ten days later the number of immature (first and second instar) sweetpotato whitefly were counted. Ten plants were assigned to treatments in a randomized block design and treated on 10 Oct with 5 treatments and a water control using a 2 gal hand sprayer at 45 psi. Treated plants were kept in a greenhouse at 80°F, 14:10 LD photoperiod, and ambient relative humidity for the remainder of the trial. A second pre-treatment count was made on day 7 (17 Oct) prior to treating 5 of the 10 plants a second time. Posttreatment counts of emerged whiteflies were taken 14 d later when adults were sure to have emerged. No apparent phytotoxicity appeared on any treatment nor were there significant differences between treatments and control after 7 days. Therefore, percent emergence was calculated using number emerged per replicate divided by the number of live immatures from this 7 day count. Results indicate that Enstar performed best.