Corn flea beetle and Stewart's wilt predictions for 2009
Ward Tingey & Jeffrey Gardner, Dept. of Entomology,
Cornell University, Ithaca.
John Gibbons, Ontario Co.
CCE,
Keith Eggleston, Northeast Regional Climate Center
Stewart's wilt is an important disease of sweet corn in New York. The disease is caused by a bacterial pathogen that is vectored almost exclusively by the corn flea beetle. The bacteria overwinter in the gut of adult flea beetles. In the spring, beetles infest early plantings of corn and transmit the pathogen to the plant by feeding and defecating on leaves. Stewart's wilt is characterized by development of conspicuous streaks on the leaves and stalk due to plugging of vascular tissue. Early wilt infections cause reduction of yield in susceptible varieties by reducing stands due to death or stunting of infected seedlings. Seedlings, which survive early infections, remain stunted, tassel prematurely, and frequently produce no ears or nubbins. Disease severity is aggravated by high temperatures, which causes faster development and movement of the bacteria through the infected plants.
Corn flea beetles spend the winter as adults near the soil
surface in grassy areas in and around cornfields. Severe winter temperatures can kill most of
the population and result in a very low incidence of Stewart's wilt disease the
following summer. Thus, a winter
temperature index is used to predict the likelihood of Stewart's wilt problems. One forecast uses the number of months with mean temperatures above 24°F for
December, January, and February. The
Stewart's wilt index (likelihood of wilt problems) is as follows:
|
Number of months > 24° F |
Predicted risk |
|
0 |
Negligible |
|
1 |
Low
to moderate |
|
2 |
Moderate
to high |
|
3 |
High |
|
|
|
2009 forecast:
The winter of 2008-2009 was on the cold
and snowy side especially in January but not cold enough to eliminate a flea
beetle threat. The Iowa model predicts a moderate to high risk throughout much
of NY except in the northern part of
the state where there is a negligible risk. Risk maps can be accessed at http://www.nrcc.cornell.edu/grass/stewart_maps.html.
The model does not account for the number of beetles entering the
winter, the insulating influence of
continuous snow cover on beetle survival,
the number of surviving beetles that actually carry the pathogen, the
influence of natural enemies and disease on beetle mortality or the effect of varietal susceptibility
to the bacterium.
Despite these knowledge gaps the model has done well in predicting
relative incidence of Stewart’s wilt.
Management
options for Stewart's wilt disease control include:
1)
planting SW- resistant varieties
2) planting
with treated seed for susceptible varieties
3)
applying a foliar insecticide spray if needed to protect seedling corn.
Additional
information on management of corn flea beetles and Stewart’s wilt is available
in the Cornell “Integrated Crop & Pest Management Guidelines for Commercial
Vegetable Production - 2009” accessible here: http://www.nysaes.cornell.edu/recommends/26frameset.html.
Tabulated risk of Stewart’s wilt for many
locations in NY:
|
|
|
|
Average °F |
|
|
|
|
Station |
County |
Dec |
Jan |
Feb |
IA Count |
Risk |
|
ADDISON |
STEUBEN |
27.9 |
16.2 |
26.3 |
2 |
Moderate to high |
|
ALBANY |
ALBANY |
28.4 |
18.3 |
27.4 |
2 |
Moderate to high |
|
Albion |
ORLEANS |
28.9 |
18.7 |
27.9 |
2 |
Moderate to high |
|
ALCOVE DAM |
ALBANY |
28.4 |
16.5 |
25.8 |
2 |
Moderate to high |
|
ANGELICA |
ALLEGANY |
27.1 |
13.9 |
24.7 |
2 |
Moderate to high |
|
Appleton |
NIAGARA |
30.0 |
19.8 |
29.1 |
2 |
Moderate to high |
|
Arkport |
STEUBEN |
28.0 |
16.5 |
27.0 |
2 |
Moderate to high |
|
AUBURN |
CAYUGA |
28.8 |
17.1 |
26.5 |
2 |
Moderate to high |
|
|
|
|
Average °F |
|
|
|
|
Station |
County |
Dec |
Jan |
Feb |
IA Count |
Risk |
|
BAINBRIDGE |
CHENANGO |
28.3 |
14.7 |
24.3 |
2 |
Moderate to high |
|
Batavia |
GENESEE |
28.5 |
22.3 |
27.0 |
2 |
Moderate to high |
|
BATH |
STEUBEN |
27.2 |
13.9 |
25.7 |
2 |
Moderate to high |
|
BINGHAMTON |
BROOME |
27.1 |
16.8 |
26.0 |
2 |
Moderate to high |
|
BLOOMINGBURG |
SULLIVAN |
29.1 |
18.7 |
27.6 |
2 |
Moderate to high |
|
BOONVILLE |
ONEIDA |
21.0 |
10.5 |
19.4 |
0 |
Negligible |
|
Branchport |
YATES |
28.0 |
18.3 |
28.0 |
2 |
Moderate to high |
|
BRIDGEHAMPTON |
SUFFOLK |
38.3 |
27.1 |
33.5 |
3 |
High |
|
BUFFALO |
ERIE |
29.4 |
18.5 |
27.2 |
2 |
Moderate to high |
|
CANTON |
ST. LAWRENCE |
23.8 |
9.4 |
21.9 |
0 |
Negligible |
|
CARMEL |
PUTNAM |
30.5 |
19.0 |
28.9 |
2 |
Moderate to high |
|
CHEMUNG |
CHEMUNG |
27.4 |
16.3 |
25.9 |
2 |
Moderate to high |
|
COBLESKILL |
SCHOHARIE |
27.6 |
15.7 |
24.6 |
2 |
Moderate to high |
|
CONKLINGVILLE |
SARATOGA |
25.9 |
14.0 |
23.2 |
1 |
Low to moderate |
|
COOPERSTOWN |
OTSEGO |
28.2 |
15.9 |
23.8 |
1 |
Low to moderate |
|
CORNING |
STEUBEN |
24.6 |
13.2 |
22.9 |
1 |
Low to moderate |
|
DANSVILLE |
LIVINGSTON |
29.5 |
17.4 |
27.2 |
2 |
Moderate to high |
|
DELHI |
DELAWARE |
28.3 |
13.7 |
24.0 |
1 |
Low to moderate |
|
DELTA DAM |
ONEIDA |
27.1 |
15.3 |
24.6 |
2 |
Moderate to high |
|
Dresden |
YATES |
29.0 |
19.3 |
28.9 |
2 |
Moderate to high |
|
DUNKIRK |
CHAUTAUQUA |
31.2 |
20.9 |
28.6 |
2 |
Moderate to high |
|
EAST SIDNEY |
DELAWARE |
28.9 |
14.0 |
24.3 |
2 |
Moderate to high |
|
Elba |
GENESEE |
26.7 |
16.2 |
25.5 |
2 |
Moderate to high |
|
ELMIRA |
CHEMUNG |
27.6 |
16.4 |
26.8 |
2 |
Moderate to high |
|
FARMINGDALE |
SUFFOLK |
36.8 |
26.9 |
34.4 |
3 |
High |
|
Farmington |
ONTARIO |
27.6 |
17.0 |
26.9 |
2 |
Moderate to high |
|
FRANKLINVILLE |
CATTARAUGUS |
26.2 |
13.1 |
23.2 |
1 |
Low to moderate |
|
Fredonia |
CHAUTAUQUA |
28.9 |
19.4 |
27.1 |
2 |
Moderate to high |
|
Freeville |
TOMPKINS |
29.0 |
16.7 |
26.9 |
2 |
Moderate to high |
|
Friend |
YATES |
28.1 |
18.4 |
28.0 |
2 |
Moderate to high |
|
FULTON OSWEGO |
OSWEGO |
27.9 |
17.9 |
25.2 |
2 |
Moderate to high |
|
Gainesville |
WYOMING |
26.1 |
15.8 |
24.8 |
2 |
Moderate to high |
|
Geneva |
ONTARIO |
28.7 |
17.5 |
27.3 |
2 |
Moderate to high |
|
GLENS FALLS |
WARREN |
24.2 |
12.5 |
21.7 |
1 |
Low to moderate |
|
GRIFFISS AFB |
ONEIDA |
28.0 |
16.1 |
24.9 |
2 |
Moderate to high |
|
Groveland |
LIVINGSTON |
29.5 |
18.8 |
28.7 |
2 |
Moderate to high |
|
HIGHMARKET |
LEWIS |
18.3 |
7.0 |
15.7 |
0 |
Negligible |
|
Himrod |
YATES |
29.7 |
19.7 |
29.4 |
2 |
Moderate to high |
|
HONEOYE |
ONTARIO |
30.0 |
17.6 |
28.3 |
2 |
Moderate to high |
|
HORNELL |
STEUBEN |
27.5 |
14.1 |
25.1 |
2 |
Moderate to high |
|
INDIAN LAKE |
HAMILTON |
21.2 |
8.7 |
18.2 |
0 |
Negligible |
|
ISLIP |
SUFFOLK |
36.7 |
26.5 |
34.1 |
3 |
High |
|
Ithaca |
TOMPKINS |
28.5 |
15.2 |
26.1 |
2 |
Moderate to high |
|
Lafayette |
ONONDAGA |
28.7 |
17.5 |
26.8 |
2 |
Moderate to high |
|
Lansing |
TOMPKINS |
29.6 |
20.0 |
29.1 |
2 |
Moderate to high |
|
LANSING MANOR |
SCHOHARIE |
31.0 |
17.1 |
25.7 |
2 |
Moderate to high |
|
LITTLE FALLS |
HERKIMER |
24.2 |
13.9 |
21.2 |
1 |
Low to moderate |
|
LOCKE |
CAUYGA |
25.0 |
11.7 |
22.0 |
1 |
Low to moderate |
|
LOWVILLE |
LEWIS |
22.0 |
10.7 |
20.2 |
0 |
Negligible |
|
MALONE |
FRANKLIN |
21.5 |
8.4 |
19.4 |
0 |
Negligible |
|
MASSENA |
OTSEGO |
21.1 |
11.1 |
20.5 |
0 |
Negligible |
|
MECKLENBURG |
SCHUYLER |
26.8 |
14.6 |
25.6 |
2 |
Moderate to high |
|
MONTGOMERY |
ORANGE |
30.8 |
20.1 |
29.7 |
2 |
Moderate to high |
|
MORRISVILLE |
MADISON |
25.3 |
14.1 |
22.6 |
1 |
Low to moderate |
|
|
|
|
Average °F |
|
|
|
|
Station |
County |
Dec |
Jan |
Feb |
IA Count |
Risk |
|
Naples |
ONTARIO |
30.5 |
19.9 |
29.6 |
2 |
Moderate to high |
|
NEW ALBION |
CATTARAUGUS |
26.3 |
15.7 |
24.5 |
2 |
Moderate to high |
|
NEWCOMB |
ESSEX |
20.3 |
8.4 |
17.9 |
0 |
Negligible |
|
NORWICH |
CHENANGO |
27.6 |
13.9 |
23.4 |
1 |
Low to moderate |
|
OCEANSIDE |
NASSAU |
37.3 |
27.4 |
34.2 |
3 |
High |
|
OLEAN |
CATTARAUGUS |
28.6 |
16.9 |
25.7 |
2 |
Moderate to high |
|
Pavilion |
GENESEE |
27.0 |
16.6 |
26.5 |
2 |
Moderate to high |
|
PENN YAN |
YATES |
29.3 |
21.4 |
27.8 |
2 |
Moderate to high |
|
PERRYSBURG |
CATTARAUGUS |
28.6 |
18.3 |
27.2 |
2 |
Moderate to high |
|
PISECO |
HAMILTON |
21.7 |
9.6 |
17.9 |
0 |
Negligible |
|
PLATTSBURGH |
CLINTON |
24.0 |
12.8 |
22.3 |
1 |
Low to moderate |
|
Potter |
YATES |
28.1 |
17.6 |
27.5 |
2 |
Moderate to high |
|
POUGHKEEPSIE |
DUTCHESS |
31.3 |
20.5 |
30.0 |
2 |
Moderate to high |
|
Prattsburg |
STEUBEN |
26.5 |
15.4 |
25.3 |
2 |
Moderate to high |
|
Ransomville |
NIAGARA |
28.0 |
18.8 |
28.3 |
2 |
Moderate to high |
|
Red Hook |
DUTCHESS |
29.8 |
19.0 |
29.0 |
2 |
Moderate to high |
|
RHINEBECK |
DUTCHESS |
28.9 |
16.0 |
26.5 |
2 |
Moderate to high |
|
ROCHESTER |
MONROE |
30.6 |
19.1 |
29.0 |
2 |
Moderate to high |
|
SARANAC |
FRANKLIN |
18.9 |
8.6 |
16.3 |
0 |
Negligible |
|
Savannah |
WAYNE |
28.3 |
18.0 |
26.9 |
2 |
Moderate to high |
|
SHERBURNE |
CHENANGO |
27.2 |
14.0 |
23.8 |
1 |
Low to moderate |
|
SLIDE MTN |
ULSTER |
24.4 |
13.0 |
21.7 |
3 |
High |
|
Sodus |
WAYNE |
28.6 |
18.2 |
26.9 |
1 |
Low to moderate |
|
SYRACUSE(SUNY) |
ONONDAGA |
29.0 |
20.1 |
26.7 |
2 |
Moderate to high |
|
SYRACUSE |
ONONDAGA |
28.9 |
18.2 |
26.3 |
2 |
Moderate to high |
|
THURSTON |
STEUBEN |
27.5 |
15.5 |
25.9 |
2 |
Moderate to high |
|
TROY |
RENSSELAER |
30.6 |
19.5 |
27.8 |
2 |
Moderate to high |
|
TUPPER LAKE |
FRANKLIN |
21.0 |
8.2 |
19.1 |
0 |
Negligible |
|
Valois |
SENECA |
29.8 |
20.2 |
28.9 |
2 |
Moderate to high |
|
WALES |
ERIE |
27.4 |
16.0 |
24.7 |
2 |
Moderate to high |
|
WARSAW |
WYOMING |
25.0 |
14.1 |
22.4 |
1 |
Low to moderate |
|
Waterport |
ORLEANS |
29.4 |
19.4 |
28.3 |
2 |
Moderate to high |
|
WATERTOWN |
JEFFERSON |
24.7 |
12.3 |
21.2 |
1 |
Low to moderate |
|
Watkins Glen |
SCHUYLER |
26.4 |
16.4 |
26.4 |
2 |
Moderate to high |
|
WAVERLY |
TIOGA |
34.0 |
20.7 |
30.0 |
2 |
Moderate to high |
|
Wayland |
STEUBEN |
27.3 |
17.2 |
27.2 |
2 |
Moderate to high |
|
WELLSVILLE |
ALLEGANY |
27.4 |
14.3 |
25.1 |
2 |
Moderate to high |
|
WELLSVILLE AP |
ALLEGANY |
25.5 |
15.9 |
25.1 |
2 |
Moderate to high |
|
WESTCHESTER |
WESTCHESTER |
34.2 |
24.0 |
32.5 |
2 |
Moderate to high |
|
WHITNEY POINT |
BROOME |
29.4 |
14.7 |
25.1 |
2 |
Moderate to high |
|
Williamson |
WAYNE |
29.2 |
19.6 |
28.1 |
2 |
Moderate to high |
|
YOUNGSTOWN |
NIAGARA |
29.8 |
19.7 |
30.1 |
2 |
Moderate to high |
·
Stations
in lower case represent Network for Environment and Weather Awareness
(NEWA) stations.