Malathion Use on Blueberries in the Pacific Northwest
Teung,
Below is the text from our May response. Again, the lower
1.2 or 1.25# ai/A rate is not effective for the control of aphids in
PNW blueberry production when malathion is used alone. Growers are
asking that EPA retain the 2# ai/A rate for blueberries. Growers can
get by with 2 applications per season unless they lose diazinon. If
that happens then they will need 3 applications per season. -- Jane
Blueberries
Growers are concerned about EPA's proposal to reduce the allowable
application rate for EC and WP formulations of malathion on blueberries.
When malathion is used in a tank mix the lower rate is not a problem;
however, in some situations, malathion is used alone for aphid control.
When the product is used alone, growers require a use rate of 2 #
ai/A. In their experience, the 1.2 # ai/A rate being proposed by
EPA is not efficacious for aphid control in blueberries when used
alone. Adequate control of aphids is essential because aphids transmit
viruses to blueberries. No comments were received on EPA's proposals
to limit applications to three per season, to establish a 7-day retreatment
interval, or to require a 25-foot buffer for aerial applications.
Growers are asking that 2 # ai/A be allowed for the use of EC and
WP formulations of malathion on blueberries.
Jane M. Thomas
Pacific Northwest Comment Coordinator
Pesticide Notification Network Coordinator
Pest Management Resource Service
Washington State University Tri-Cities
2710 University Drive
Richland, WA 99354
phone: 509-372-7493
fax: 509-372-7491
