Open AccessEffects of Host Resistance and Inoculum Density on the Suppression of Fusarium Wilt of Watermelon Induced by Hairy Vetch
Author(s) -
XinGen Zhou,
Kathryne L. Everts
Publication year - 2007
Publication title -
plant disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.663
H-Index - 108
eISSN - 1943-7692
pISSN - 0191-2917
DOI - 10.1094/pd-91-0092
Subject(s) - fusarium wilt , vicia villosa , biology , citrullus lanatus , fusarium oxysporum , cultivar , agronomy , bacterial wilt , fusarium oxysporum f.sp. lycopersici , horticulture , wilt disease , cover crop
Hairy vetch (Vicia villosa) used as a soil amendment is a newly described potential management tool for the suppression of Fusarium wilt of watermelon (Citrullus lanatus). However, the effect of inoculum density and the level of resistance in the host on the level of suppression are not understood. In this study, hairy vetch-induced wilt suppression was evaluated in the greenhouse on 12 watermelon cultivars with different levels of wilt resistance and in 16 naturally infested soil samples collected from commercial watermelon fields. Wilt suppression occurred in all but two cultivars and with the trend that suppression increased as the level of resistance in cultivars increased. Fusarium wilt suppression was 22, 53, and 63% in hairy vetch-amended soil compared with nonamended soil on cultivars ranked as susceptible, moderately resistant, and highly resistant, respectively. Suppression also occurred in nine of the soils that contained populations of Fusarium oxysporum f. sp. niveum below 1,100 CFU/g of soil. However, at this level or higher, significant wilt suppression was not observed. The magnitude of disease suppression decreased with the increase of inoculum in the soils. The induced wilt suppression appeared to be correlated with an increase in bacterial populations in soil. Hairy vetch-induced suppression to Fusarium wilt in watermelon is dependent on the resistance level of cultivars and is overcome by high inoculum level of F. oxysporum f. sp. niveum in soil.