Natural Migration of Rotylenchulus reniformis In a No-Till Cotton System

摘要

Rotylenchulus reniformis is the most damaging nematode pathogen of cotton in Alabama.It is easily introduced into cotton ?elds via contaminated equipment and, when present, is dif?cult and costly to control.A trial to monitor the natural migration of R.reniformis from an initial point of origin was established in 2007 and studied over two growing seasons in both irrigated and nonirrigatedno-till cottonproduction systems.Vermiform females,juvenilesand malesreacheda horizontaldistanceof 200 cm from the initial inoculation point, and a depth of 91 cm in the ?rst season in both systems.Irrigation had no effect on the migration of vermiform females and juveniles, but males migrated faster in the irrigated trial than in the non-irrigated trial.Population density increased steadily in the irrigated trial during both years, exceeding the economic threshold of 1,000 per 150 cm3, but was highly correlated with rainfall in the non-irrigated trial.The average speed of migration ranged from 0- to 3.3-cm per day over 150 days.R.reniformis was able to establish in both the irrigated and non-irrigated trials in one season and to increase population density signi?cantly.