Diane Alston, Utah State University entomologist,
outlined onion thrip biology and control options for the growers.
“Growers need to understand that continued reliance on a single
class of insecticides creates the likelihood of resistance,”
said Alston, “and that resistance may play a role in IYSV.”
By continuing to study the biology and ecology of thrips, Alston hopes
to find the weak link in the lifecycle and thus improve pest managment.
In 2004, she noted that re-population in the field, or on a plant,
was due to incomplete kill rather than thrips moving on to a plant
from outside the area. Softer insecticides, like Spinocide, worked
as well as Mustang. In 2005, her research efforts will be directed
at looking at thrip movements in the field and how important thrips
re-introduction from outside the field is to overall thrips populations.
Utah State University student Rachael Gibson outlined a potential
strategy for sweet onion production.
“Growers need to realize that while long, hot days acceralte
bulbing in sweet onion varieties, there is a lot of variation from
plant to plant,” she said. “I’m going to look for
plants that grow more leaves and bulb later, which may indicate better
adaptation to our local conditions.”
