|CHAGOYA, JENNIFER - Texas Agrilife Extension|
|MONCLOVA-SANTANA, CECILIA - Texas Agrilife Extension|
|WHEELER, TERRY - Texas Agrilife Extension|
Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/20/2021
Publication Date: 8/6/2021
Citation: Chagoya, J., Monclova-Santana, C., Wheeler, T., Ulloa, M. 2021. Fusarium oxysporum f. SP. Vasinfectum race 4 soil quantification in pima and upland cotton cultivars. American Phytopathological Society Annual Meeting.
Technical Abstract: Fusarium oxysporum f. sp. vasinfectum race 4 (FOV4) is a soilborne pathogen that causes devastating losses in cotton (Gossypium spp.). Reported in El Paso in 2017, cotton stakeholders in Texas seek to understand the inoculum dynamics, dispersal, and control. The objective of this research is to quantify FOV4 in soil in response to growing resistant and susceptible Pima (G. barbadense L.) and Upland (G. hirsutum L.) cultivars. This trial consisted of a resistant and susceptible Pima, and tolerant and a susceptible Upland planted in sixteen replications in El Paso, TX in 2020. Plant survival, root vascular necrosis, and yield were collected in the field. DNA was extracted from soil samples at planting (0 DAP), midseason (55 DAP), and harvest (143 DAP). FOV4 was quantified using real-time PCR. Significant differences among cultivars were observed for all field measures and midseason FOV4 quantity. Susceptible cultivars showed lower survival, higher root necrosis, lower yield, and elevated FOV4 quantity. Upland cultivars showed fewer symptoms than Pima cultivars; however, susceptible Upland and susceptible Pima did not have significant differences in midseason FOV4 quantities. FOV4 quantity at planting was negatively correlated with plant survival, and positively correlated with root necrosis showing that inoculum presence at planting can impact disease progression during the season. This research shows that the planting of resistant cultivars prevented an increase of FOV4 in the soil during the growing season, thus suggesting potential for disease management.