|Peres, Natalia - UNIV. OF FLORIDA|
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: April 1, 2008
Publication Date: June 1, 2008
Citation: Turechek, W., Peres, N. 2008. Evaluating Hot-Water Treatment as Means to Reduce Xanthomonas fragariae in Strawberry Nursery Stock: Field trials.. Phytopathology. 98(6)S160 Technical Abstract: Angular leaf spot (ALS) is an important disease of strawberry that is transmitted to production fields through infected nursery stock. This creates problems for nurseries who export plants to Europe because of quarantine restrictions and for US growers who expect to receive pathogen-free plants. The southeastern states are particularly vulnerable to ALS due to the likelihood that overhead irrigation will be used for frost protection during the season. In previous reports, we showed that bacterial populations were reduced >99% when exposed to 2 hr at 48 C or 4 hr at 44 C. These same treatments were applied to several different strawberry cultivars in greenhouse trials to determine if the plants could withstand the heat treatment. A few varieties, notably ‘Ventana’ and ‘Diamante’ were severely stunted at 48 C, but faired better at 44 C. In this poster, we report on the results of field trials conducted in Maryland and Florida where several varieties were treated, planted in raised beds and then evaluated for their ability to withstand heat treatment and incidence of ALS. The survival rate amongst cultivars was variable, but generally was high for varieties that showed good tolerance to heat treatment. The development of ALS was observed at very low incidence in only a few of the heat-treated plots. However, the incidence of ALS was significantly higher in untreated plots, particularly in Florida, where nearly all control plots developed the disease. These results indicating that heat treatment may not be suitable for all varieties due to their inability to withstand heat treatment, but were very promising for those that could. We intend to continue with this work and develop a protocol that could be implemented at the production scale.