| Greenhouse, field, and survey studies were employed to investigate the geographical distribution and interrelationship of T. basicola and R. reniformis, in different soil types on cotton. Concomitant inoculations resulted in decreased plant vigor. In biotron studies, R. reniformis was significantly increased in the presence of the fungus on Caledonia soil, while T. basicola populations were higher in the presence of the nematode on Bosket and Caledonia soils. In the field plots, only R. reniformis was increased in the presence of the fungus on Bosket and Grenada soils. Yield was measured only in the field plots and was higher in the control treatments on Bosket, Grenada, and Brooksville soils. Prior inoculation with either pathogen did not predispose the plant to the secondary pathogen. Thielaviopsis basicola was isolated in 28.6% of the survey samples and fourteen plant-parasitic nematode genera and species were identified. |
