Professor and County Area Fruit Agent
Rutgers Cooperative Extension, 4 Gauntt Place
Flemington, NJ 08822
cowgill@aesop.rutgers.edu
http://orchard.uvm.edu/win/win.html
Objective: Determine the efficacy of one and two
applications of CHAMP FORMULA 2 FLOWABLE copper fungicide in controlling
fireblight infection the year following a growing season with severe infection.
Location: Chazy Orchards, Chazy NY. Chazy Orchards (above),
first planted in 1926, call themselves the 'largest McIntosh orchard in
the world.' Brothers and owner-operators Tré and Jeff Green produced
almost 200,000 bushels of McIntosh in 1997--one of their largest crops ever.
The block of Paulareds chosen for this work was severely infected with fireblight
in 1996 a very wet growing season throughout the Northeast. Paulared on
M26 rootstock is an extremely fireblight susceptible cultivar/rootstock
combination. This combination of inoculum and suitable cultivar/rootstock
combination made this an ideal location to evaluate the efficacy of a copper
fungicide in controlling fireblight. Tré Green and his field staff
were very concerned about the prospect of significant fireblight reinfection
in 1997.
CHAMP FORMULA 2 FLOWABLE applications were in a large block of predominantly
6th leaf Paulred/M26. Seven year old Pioneer Mac's/M26 were planted as pollenizers
every sixth row. The vigor and productivity of this block was low as back
to back severe winter weather following planting stunted tree growth.
Treatments: CHAMP FORMULA 2 FLOWABLE fungicide treatments were
applied to the Paulared/M26 in an approximately four acre block. Rates were
determined by following the label recommendations. All treatments were applied
dilute at 300 GPA, with the growers Meyers airblast speed sprayer. Treatments
were not randomized, but rather applied as whole blocks of two acres each:
Treatments
Treatment 1 CHAMP was applied at the label rate of 1-1/3 pints
per acre.The application was made on April 30, 1997 at Green Tip stage in
the early am. The weather conditions were as follows at application: Temperature
570F, calm wind, and fair skies. Approximately two acres were treated.
Treatment 2 CHAMP was applied at the label rate of 1-1/3
pints per acre. The application was made on April 30, 1997 at Green Tip
followed by a second application of Champ at 2/3 pint per acre on May 7,
1997 dilute at 300 GPA. Weather conditions were as follows at the second
application: Temperature 450F. with calm winds and fair skies. Approximately
two acres were treated.
Treatment 3 Untreated control
Because of the growers concern for a repeat fireblight epidemic, only a
small section of the block was left unsprayed to serve as Treatment 3, the
Untreated control.
Evaluation: The treated blocks were inspected in late June
for visible signs of fireblight infection. Fifty trees in each treatment
were evaluated for fireblight strikes. No blossom blight was evident.
CHAMP FORMULA 2 FLOWABLE treatment results: Fireblight Strike
Treatment Number of Strikes post bloom
Treatment 1 -- 3 strikes
Treatment 2 -- 0 strikes
Treatment 3 -- 2 strikes
The potential fireblight strikes were collected and sent to the Rutgers
Diagnostic Lab for evaluation. Fireblight could not be isolated from the
samples.
Our results were inconclusive because of the poor weather conditions for
fireblight development this season. Weather conditions during the period
mid-May through early July were noticeably cool (May) and dry (June). It
should be noted that 1997 weather conditions in general were not conducive
to fireblight development throughout the region--i.e., there were few fireblight
outbreaks in New England this year.
No phytotoxicity was observed in any of the treatments.
While no statistical differences were evident between treatments, the grower-cooperators
were impressed with the perceived efficacy of Champ, Their statement, "rows
that got a double shot of CHAMP had no fireblight", sums it up their
experience with Champ fungicide.
Conclusion: The efficacy of properly applied early (Green Tip)
copper applications to control fireblight in apple orchards is well documented.
Unfortunately, results this year were inconclusive on the differences between
the treatments applied. Still, observations from this trial suggest CHAMP
FORMULA 2 FLOWABLE is a suitable prophylactic to assist in the prevention
of fireblight infection in apple orchards. More research in a fireblight
infection susceptible season would be beneficial to document the efficacy
of CHAMP in controlling fireblight and other fungal diseases.