Evaluation of Fusarium Wilt Resistance in Cotton Cultivars and Identification of Pathogenic Races of Fusarium Oxysporum f. Sp. Vasinfectum in Alabama

Fusarium oxysporum f. sp. vasinfectum (FOV) is the causal agent of the fungal disease Fusarium wilt in cotton.  Objectives of this study are to 1) Observe commercial variety responses to Fusarium wilt and root-knot nematodes (Meloidogyne incognita) and compare to yield and 2) Identify races of FOV present at the site of the Commercial Fusarium Wilt Trial. The projected outcome of these experiments is to be able to more effectively control the Fusarium wilt root-knot nematode disease complex in the southeastern United States with resistant varieties being the main control measures.  Results showed four varieties having statistically similar yields to the resistant check M-315: Stoneville 4747 GLB2, Stoneville 4946 GLB2, Phytogen 427 WRF, and Phytogen 499 WRF.  Eleven of sixteen cultivars showed statistically similar Fusarium wilt percentages to the resistant check M-315.  Nine of sixteen cultivars tested had statistically similar root-knot egg reproduction factors compared to the resistant check M-315.  There is a diversity of FOV races present at the Plant Breeding Unit, making this location ideal for a field trial.  Races 1, 8, LA 108, and LA 127/140 were found to be present in 2014.