Field Identification of Commercial Cucumber Cultivars With Reduced Silverleaf Whitefly Infestation and Tolerance to Whitefly-Transmitted Viruses in the Southeastern United States
Abstract
Field trials were conducted during the fall seasons 2023 and 2024 in Tifton, GA, USA, to evaluate 10 cucumber ( Cucumis sativus L.) cultivars for resistance to silverleaf whitefly (SLWF) and tolerance to whitefly-transmitted viruses (WTVs). Nine slicer-type cultivars (Brickyard, Bristol, Cobra, Dasher II, Diamondback, Python, Raceway, Speedway, and Tasty Green) and one pickling-type cultivar (Supremo) were arranged in a randomized complete block design with four replications. ‘Dasher II’ served as the grower’s standard check. Trichome densities (trichomes/cm 2 leaf area) differed significantly among cultivars, with Bristol (13.0), Supremo (8.5), and Raceway (8.5) exhibiting the highest density. Similarly, ‘Bristol’ (1.3), ‘Dasher II’ (10.0), ‘Supremo’ (14.0), and ‘Brickyard’ (16.5) harbored the lowest SLWF egg densities (eggs/cm 2 leaf area). In addition, cultivars Bristol (0.67), Diamondback (2.0), Brickyard (3.3), Raceway (3.5), and Dasher II (3.75) recorded the least nymph densities (nymphs/cm 2 leaf area). Furthermore, ‘Bristol’ (0.76) and ‘Diamondback’ (1.01) had the fewest adults’ abundance (adults/cm 2 leaf area). Area under the disease progress curve (AUDPC) for virus incidence was smallest in cultivars Bristol (717), Diamondback (928), Dasher II (945), and Supremo (954). Cultivars Bristol (6.5), Supremo (15), and Dasher II (24.5) exhibited the smallest aligned rank transformed (ART) mean for virus severity. Notably, trichome density was negatively correlated with WTVs incidence and severity. Cultivars Bristol (29,361 kg·ha −1 ), Dasher II (26,332.8 kg·ha −1 ), Brickyard (22,972.4 kg·ha −1 ), Diamondback (22,595 kg·ha −1 ), and Cobra (22,565 kg·ha −1 ) exhibited the highest marketable fruit weight. Despite having the smallest fruit size, cultivar Supremo produced the most marketable fruit numbers. Overall, Bristol, Supremo, Dasher II, and Diamondback were the most promising cultivars under natural SLWF and WTVs pressure in the southeastern United States.