tabaci larvae, all onion leaves were tested for IYSV by DAS-ELISA (Clark & Adams 1977) and commercially available antibodies, as well as positive and negative controls for IYSV (Agdia Inc.
tabaci larvae was counted in each pot, and onion leaves were taken to the lab and tested for IYSV by DAS-ELISA, as described above.
A logistic regression model for IYSV infection levels was performed using PROC GENMOD and controlled for blocks (SAS Institute 2003).
These results indicated the absence of an association between resistance to onion thrips and their response to IYSV following T.
The percentage of plants infected with IYSV varied from 36.
tabaci-resistant onion cultivars to IYSV in the field and in the laboratory by detecting the presence of IYSV by DAS-ELISA.
In the present study, all cultivars became infected with IYSV in both lab and field experiments and this agrees with results from past studies, where more than 40 onion cultivars were tested for the presence of IYSV, and cultivars resistant to T.
2010) observed that visual symptoms of IYSV were mild to absent in onion fields in New York and usually appeared at the end of the season, which suggested that reductions in plant and bulb size were due to T.
Because host resistance to the virus has not been found, efforts to control IYSV should focus on a combination of control or management strategies, including sanitation practices, such as elimination of volunteer onions and planting of transplants free of T.