An Evaluation of Rotylenchulus Reniformis Resistant Cotton Lines in the Nematode-Infested Fields Using Classical Growth Analysis.

The average loss in cotton production due to Rotylenchulus reniformis in Mississippi exceeds 8% on average. Currently, there are no commercially available cultivars resistant to reniform nematode, which limits producers to chemical control methods. A field experiment was therefore conducted to evaluate new resistant cotton lines (Gossypium barbadense introgressions; 08SS110-NE06.OP and 08SS100) to reniform nematode infection along with a susceptible genetic standard (Deltapine 16) and commercial susceptible cultivar (PHY 490 W3FE) based on plant growth, development, and yield responses. All the four genotypes were grown in the soils naturally infested with reniform nematode exceeding or at economic thresholds. Classical growth analysis metrics such as plant height, leaf area, and plant dry matter were used to derive various crop growth indices. Yield parameters such as boll number, size, seed per boll, and lint yields, were determined by hand harvesting two meter rows from each plot. Reniform nematode populations were extracted from soil samples and counted at planting, peak bloom, and after harvest. The study observed significantly lower reniform nematode counts at in the plots containing resistant lines compared to susceptible varieties. Further, we observed a lesser degree of damage caused by reniform nematode on resistant lines based on growth analysis. The study will be helpful for the exploitation of these lines for the development of resistant commercial cultivars and may provide a long-term, non-chemical control solution to producers.