BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 75 
Chemicals and power sprayers reduce eradication costs 
Effective formulations of hormone-type sprays were used to kill 
native barberries in Colorado, Virginia, and West Virginia. The 
sprays were applied with special compressed-air equipment. This 
method of destroying native barberries reduced the cost of the work 
by about 60 percent and hastened its progress. 
Tests were run in an effort to find a more effective chemical for 
destroying the common barberry, Berberis vulgaris. It can be effec- 
tively killed with ammonium sulfamate, but the application of this 
chemical is too slow and costs too much where barberries are numer- 
ous. Some formulations of 2,4-D and 2,4,5-T, tried as a foilage spray 
and basal-stem treatment, look promising. 
Trial flights were made to determine the practicability of using the 
helicopter for barberry surveys. Based on two tests, it appears that 
some sites can be initially surveyed by this method economically and 
effectively. More tests are needed to determine its place in barberry- 
eradication work, however. 
Nurseries inspected for rust-susceptible barberry 
Barberry plants were inspected in 257 nurseries in 37 States. These 
nurseries and 39 dealers were authorized to move interstate approved 
rust-resistant barberry and mahonia plants. The nurseries examined 
had 17 million barberry and mahonia plants, of which 1,236 were sus- 
ceptible to stem rust. Nurserymen cooperated effectively by promptly 
destroying the susceptible plants. Most nurserymen now produce 
their own barberry seed and grow only rust-resistant barberry plants. 
This further reduces the possibility of rust-spreading barberry plants 
being distributed in the nursery trade. 
Organization changed 
Organization changes are made in barberry eradication as the work 
reaches a maintenance status in the cooperating States. This has 
resulted in combining the maintenance activities in two States under 
one individual. Five such combinations, involving 10 States, have 
been made. 
Campaign Against Insect Vectors of Peach Diseases Continued 
Destruction of leafhoppers may control spread of phony peach 
disease 
Preliminary observations of peach trees that had been sprayed with 
DDT in 1947 and 1948 indicate that it may be possible to control the 
natural spread of phony peach disease with sprays that destroy the 
leafhopper carriers of the disease virus. The observations were made 
in two peach orchards near Fort Valley, Ga. Part of each orchard 
received the DDT sprays; part did not. In 1950 the sprayed trees 
developed fewer cases of phony peach than the unsprayed trees. 
In addition to these experiments, a large-scale spraying program in 
the Fort Valley area was continued for a second year. Ninety thou- 
sand peach trees in an isolated area were sprayed with DDT. As the 
virus causing the disease may require as long as 3 years for incubation, 
the full results of this work cannot be observed until 1952 or later. 
