ARS | Publication request: Natural migration of rotylenchulus reniformis in a no-till cotton system

Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 24, 2010
Publication Date: December 1, 2010
Repository URL: http://handle.nal.usda.gov/10113/54286
Citation: Moore, S.R., Lawrence, K.S., Arriaga, F.J., Burmester, C.H., Van Santen, E. 2010. Natural migration of rotylenchulus reniformis in a no-till cotton system. Journal of Nematology. 42(4):307-312.

Interpretive Summary: The reniform root nematode (Rotylenchulus reniformis) is the most economically damaging pathogen of cotton in Alabama. It is easily introduced into cotton fields via contaminated equipment and when present, is difficult and costly to control. However, little information is available on the natural movement of this nematode once it is in a field. An experiment to monitor the natural migration of this nematode was established in 2007 and monitored over two years in both irrigated and non-irrigated no-till cotton production systems. Females, juveniles and males moved 6.5 ft (200-cm) horizontally and 3 ft (91-cm) vertically in the first year under irrigated and non-irrigated conditions. Irrigation had no effect on the migration of females and juveniles, but males migrated faster with irrigation. Population density increased steadily with irrigation both years of this experiment, and was highly correlated to rainfall in the non-irrigated treatments. The speed of migration ranged from 0 to 1.3 in per day (3.3-cm per day). The reniform nematode established itself under irrigated and non-irrigated conditions in one season, with populations increasing significantly during the cotton growing season. This data contradicts the current belief that nematodes migrate very short distances naturally during the growing season, and might help in developing new management techniques.

Technical Abstract: Rotylenchulus reniformis is the most economically damaging pathogen of cotton in Alabama. It is easily introduced into cotton fields via contaminated equipment and when present, is difficult 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 monitored over two years in both irrigated and non-irrigated no-till cotton production systems. Vermiform females, juveniles and males reached a horizontal distance of 200-cm from the initial inoculation point, and a depth of 91-cm in the first season in both trials. 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, but was highly correlated with rainfall in the non-irrigated trial. The speed of migration ranged from 0 to 3.3-cm per day. Rotylenchulus reniformis was able to become established in both the irrigated and non-irrigated trials in one season, and to increase population density significantly.