Guardian Angel Protects Peach TreesBy
Guardian, a new peach tree rootstock, has begun helping growers battle the
leading cause of peach tree death in the southeast. Peach tree short life (PTSL)
costs growers about $10 million annually. It strikes in the spring, usually when
the trees are 3 to 7 years old.
Horticulturist Thomas G. Beckman with the
Agricultural Research Service
co-developed the rootstock with Clemson
University scientists. ARS is the chief research agency of the
U.S. Department of Agriculture.
Guardian proved its value during its first field tests from 1989 to 1996 in
South Carolina and Georgia. There, scientists planted trees on Guardian
rootstock and compared them to trees grown on two commonly used commercial
rootstocks, Lovell and Nemaguard. Lovell has tolerance to PTSL; Nemaguard
resists root knot nematodes. Guardian has a unique combination of resistance to
The two-pronged protection paid off. By 1996, no Guardian trees were lost to
PTSL in test orchards in South Carolina, and only 20 percent were lost in
Georgia. By contrast, 97 percent of the Lovell trees in South Carolina died; 40
percent in Georgia. For Nemaguard, 95 percent of South Carolina's trees, and 80
percent of Georgia's, succumbed to the disease.
ARS and Clemson University have jointly applied for a plant variety
protection certificate on Guardian rootstock, which is available only through
An in-depth article on this research appears in the October issue of Agricultural
Research magazine. The story is also on the World Wide Web at:
Scientific contact: Thomas G. Beckman, ARS
and Tree Nut Research Laboratory, Byron, Ga., phone (912) 956-6436, fax
(912) 956-2929, email@example.com.