News from Cornell University:
Cornell University plant breeders have released a new alfalfa variety
with some resistance against the alfalfa snout beetle, which has ravaged
alfalfa fields in nine northern New York counties and across the St.
Lawrence River in Canada.
There are no other known alfalfa snout beetle infestations in North
America, but the pesky beetle has been spreading. The snout beetle’s
larvae feed on and damage the alfalfa plant’s roots, limiting yields for
this major livestock feed.
“We are the only ones who can work on [this pest], because it is so
regional,” said Don Viands, professor of plant breeding and genetics and
director of the Forage Breeding Project.
The new resistant cultivar, called Seedway 9558 SBR, has been in
development since 2003, along with six other populations. But Seedway
9558 SBR has provided the most resistance while also maintaining the
On a scale of one to five, where one represents little to no
root-feeding damage and five is severe root-feeding damage, Seedway 9558
SBR scored a 2.9.
“This initial variety is better than anything else, but we feel we
can still do better,” Viands said. “We are trying to get a variety that
is at least twice as good as this one.”
For effective control, the resistant alfalfa should be planted with a
larvae-killing nematode that has been studied and released by Elson
Shields, professor of entomology, said Viands.
“We are making significant progress in developing resistance, but it
has been very slow,” Viands said. The first-year base crop for Seedway
9558 SBR was 13 percent resistant, compared with 38 percent after seven
cycles. “Normally it takes four to five cycles to develop resistance,
but this [alfalfa snout beetle resistance] may have multiple genes, so
it is taking time,” Viands added, noting that it is still unknown
exactly what mechanism allows the plant to deter the beetles.