Sprinkler irrigation as a management practice for Bemisia tabaci (Homoptera: Aleyrodidae) in cotton fields

Field experiments were conducted in 1999 and 2000 to investigate the effect of irrigation method on populations of Bemisia tabaci (Gennadius) and natural enemies in cotton fields in Aydin Province, Turkey. Two irrigation methods, sprinkler and border, were studied each year. All plots were irrigated during different phenological periods including initial bloom, boll initiation, 50% boll filling and 5-10% boll opening stages. Irrigation methods and periods significantly affected whitefly populations. Densities of B. tabaci were significantly reduced in sprinkler-irrigated plots compared to border-irrigated plots in 2000 but not in 1999. Irrigation methods did not affect the population of natural enemies. However, significant differences in numbers of natural enemies were observed among irrigation periods. Natural enemies were most abundant during the second irrigation period when whiteflies were also most abundant. These results suggest that sprinkler irrigation may be useful in cotton fields as a management practice for whitefly without reducing natural enemy populations.