Agronomic characterization of cotton genotypes susceptible and resistant to reniform nematode in the United States Midsouth

Abstract

AbstractCotton (Gossypium hirsutum L.) genotypes resistant to reniform nematode (RN) (Rotylenchulus reniformis Linford and Oliveira) have been recently developed to reduce yield losses from RN, yet little is known of their agronomic responses under field conditions. This research was conducted to determine if RN population vary cotton growth and development and yield among RN resistant (G. barbadense introgressions; 08SS110‐NE06.OP and 08SS100) and susceptible cotton genotypes (Deltapine 16 and PHY 490 W3FE) in environments infested with RN. The study was conducted over 2 yr (2017 and 2018) in field plots naturally infested with RN population. Growth analysis was conducted at 1‐ or 2‐wk intervals starting from 4 wk after planting (WAP) to 12 WAP. Soil samples were taken from the top 40‐cm soil depth before planting and after harvesting to determine RN populations. The three‐parameter sigmoidal functions best described (r2 = .95–.99) growth of cotton genotypes along the season, but no differences were observed for maximum growth rates among genotypes. Post‐harvest RN populations significantly increased in plots grown with susceptible cotton genotypes, while RN reproduction was inhibited resulting in a fewer number of RN in the resistant genotypes‐grown soils. 08SS110‐NE06.OP exhibited greater vigor than PHY 490 W3FE in the later part of season. PHY 490 W3FE showed comparable yields with 08SS110‐NE06.OP despite differing in RN suppression and vigor in the later season. The information in this study could be useful to select resistant lines superior in yields and RN suppression as a parent for the development of RN resistant cultivars in cotton.