Pest & Crop

Newsletter


Purdue Cooperative Extension Service

IN THIS ISSUE

Issue 17, July 20, 2017 • USDA-NIFA Extension IPM Grant




Insects, Mites, and Nematodes

Agronomy Tips

Plant Diseases

Weather Update

INSECTS, MITES, & NEMATODES




Western Bean Cutworm Flight Continues, Scout High Risk Areas Now (Christian Krupke) -



• Western bean cutworm flight still impressive.
• Scouting for eggs should continue for fields not yet treated.
• Most Bt hybrids will not give control, scouting + insecticide treatment is only option.
• If possible wait until 90-95% tassel emergence before insecticide treatment.

According to our moth captures from the last week (see trap report) we are just past peak moth flight, that means more to come. The large flight this season, in northern Indiana and adjoining areas of Ohio and Michigan, are the result of the many fields found infested with larvae late last year. So high numbers of caterpillars entered the winter, which proved to be a mild one. In short, the high pressure is no surprise. This pest is potentially damaging to almost all corn in the region, because the Bt trait commonly found in the vast majority of corn hybrids (Cry1F) offer no control of this pest; resistance is a reality now <http://msuent.com/assets/pdf/BtTraitTable15March2017.pdf>.

Scouting and treatment are essential to prevent ear feeding and infection by the potentially even more damaging ear rot fungi that can readily develop in damaged ears later in the season.

Many pest managers are finding fields over the 5% (plants with one egg mass) threshold although the tassel/silks have not yet emerged. In cases like this, the best bet is to wait until 90-95% silking, even though eggs will continue to be laid and hatch. The young caterpillars will feed in leaf axils until the plant enters the reproductive stages and can be contacted with insecticides during their “final walk” from axils to the developing ear. Most producers will not want to spray twice, so the best way to maximize efficacy is to wait and get as many of the larvae as possible when the lure of the silk is present. Of course, once caterpillars are in the ear all hope of insecticidal control is lost. On a positive note, we have seen, first-hand, that even fields that with over 25% of plants with egg masses can be treated with insecticides and obtain excellent results. There are many compounds available, see the list here <http://extension.entm.purdue.edu/publications/E-219.pdf>.


Young WBC larva feeding in leaf axil before heading to the ear.

Young WBC larva feeding in leaf axil before heading to the ear.




back to top



2017 Western Bean Cutworm Pheromone Trap Report(John Obermeyer) -



County Cooperator WBC Trapped
Week 1
6/22/17 - 6/28/17
Week 2
6/29/17 - 7/5/17
Week 3
7/6/17 - 7/12/17
Week 4
7/13/17 - 7/19/17
Adams Kaminsky/New Era Ag 0 6 4  
Adams Roe/Mercer Landmark 0 8 6 1
Allen Anderson/Syngenta Seed 0 4 26  
Allen Gynn/Southwind Farms 0 8 13 15
Allen Kneubuhler/G&K Concepts/Harlan 0 4 13 4
Allen Kneubuhler/G&K Concepts/Koch 0 10 0 4
Bartholomew Bush/Pioneer Hybrids 0 0 0 0
Clay Bower/Ceres Solutions/Clay City   0 0 0
Clay Bower/Ceres Solutions/Brazil   0 0 0
Clinton Emanuel/Boone Co. CES 1 1 1 0
Clinton Foster/Purdue Entomology 0 0 2 1
DeKalb Hoffman/ATA Solutions     87 174
Dubois Eck/Purdue CES 0 1 0 0
Elkhart Kauffman/Crop Tech Inc.   35 156 150
Fayette Schelle/Falmouth Farm Supply Inc. 1 1 0  
Fountain Mroczkiewicz/Syngenta 41 31 14 4
Fulton Jenkins/N. Central Coop/Talma 379 385 167 76
Fulton Ranstead/N. Central Coop/Rochester     309 46
Gibson Schmitz/Gibson Co. CES 0 0 2  
Hamilton Campbell/Beck's Hybrids 3 2 2 2
Hendricks Nicholson/Nicholson Consulting 0 1 1  
Jasper Overstreet/Purdue CES 438 410 304 237
Jasper Ritter/Brodbeck Seeds 302 171 124 97
Jay Boyer/Davis PAC 5 1 0 3
Jay Shrack/Ran Del Agri Services 0 0 0 1
Jay Temple/Jay County CES/Pennville 0 1 3 2
Jay Temple/Jay County CES/Redkey 3 4 7 2
Jennings Bauerle/SEPAC 0 0 0 1
Knox Bower/Ceres Solutions/Vincennes   0 0 0
Knox Bower/Ceres Solutions/Freelandville   0 0  
Kosciusko Klotz/Etna Green 75 112 92 46
Lake Kleine/Kleine Farms 0 4 41 11
Lake Moyer/Dekalb Hybrids, Shelby 157 108 63 16
Lake Moyer/Dekalb Hybrids, Schneider 246 151 101 93
LaPorte Rocke/Agri-Mgmt Solutions, Wanatah 120 122 321 138
LaPorte Smith/Co-Alliance/LaPorte 0 11 29 22
LaPorte Smith/Co-Alliance/Fish Lake 6 20 109 107
LaPorte Smith/Co-Alliance/Union Mills 15 19 122 100
LaPorte Smith/Co-Alliance/LaCrosse 35 149 337 112
Marshall Harrell/Harrell Ag Services   4 118  
Marshall Klotz/SR 10 & SR 331 29 81 130 90
Marshall Miller/North Central Coop     48 43
Miami Early/Pioneer Hybrids 189 216 140 154
Newton Moyer/Dekalb Hybrids, Lake Village 16 139 262 193
Porter Leuck/PPAC 11 17 335 287
Pulaski Capouch/M&R Ag Services 42 49    
Pulaski Leman/North Central Coop 4 22 34  
Putnam Nicholson/Nicholson Consulting 0 2 0  
Randolph Boyer/DPAC 2 2 3 0
Rush Schelle/Falmouth Farm Supply Inc.   0 0  
Shelby Fisher/Shelby Co. Co-Op 0 0 0  
Shelby Simpson/Simpson Farms 4 5 2 0
Starke Capouch/M&R Ag Services 0 184    
Starke David Wickert/Wickert Consulting 5 28 21 10
Starke Larry Wickert/Wickert Consulting 136 292 185 16
St. Joseph Barry/Helena 3 28 108 56
St. Joseph Gary Battles 1 12 16 16
St. Joseph Carbiener/Union Twp. 0 11 50 19
St. Joseph Smith/Co-Alliance/Granger 7 46 87 69
St. Joseph Smith/Co-Alliance/New Carlisle 0 3 69 93
Sullivan Bower/Ceres Solutions/Farmersburg   0 0 0
Tippecanoe Bower/Ceres Solutions/Sullivan   0 8 0
Tippecanoe Bower/Ceres Solutions/Lafayette   15 25 24
Tippecanoe Nagel/Ceres Solutions 1 1 6  
Tippecanoe Obermeyer/Purdue Entomology 0 0 0 0
Tippecanoe Westerfeld/Monsanto 2 3 0  
Tipton Campbell/Beck's Hybrids 0 2 0 0
Vermillion Bower/Ceres Solutions/Clinton   0 0 0
Wabash Enyeart/North Central Coop 1 10 15  
Whitley Richards/NEPAC 23 70 39 13
Whitley Richards/NEPAC     182 101

back to top



2017 Corn Earworm Pheromone Trap Report (John Obermeyer) -




Corn Earworm Trap Report

Corn Earworm Trap Report



back to top

Agronomy Tips




VIDEO: Soybean Leaf Sampling for Nutritional Needs(Shaun Casteel and John Obermeyer) -



It is very important to select the correct soybean leaves when tissue sampling to determine nutritional needs during the growing season. The most recent, mature trifoliate leaf will provide the truest assessment of the plant’s nutrition. This is usually the leaves from the third or fourth nodes from the top of the plant, depending on the development of the upper most trifoliate. If the upper most leaf is less than, or equal to, the size a quarter then pull the trifoliate leaf from the fourth node for your sample. However, if the upper most leaf is equal to, or greater than, the size of a half dollar, then chose the trifoliate leaf from the third node. For each sample submitted to a laboratory for analysis, pull 20-25 trifoliate leaves in the desired area, placed loosely in a paper bag marked with identifiers such as name, field, location, date, and growth stage of the soybean. Do not allow the leaves to remain moist, as they will mold quickly and ruin the sample.

If you are tissue sampling multiple times during the season, you should wait at least 10-14 days between samples. This will allow any past foliar fertilizer(s) applied to be incorporated into the plant and assessed. It will also test a new set of nodal leaves that have developed since the last sampling.




back to top

PLANT DISEASES




Southern Rust of Corn Confirmed in Kentucky (Carl Bradley and Kiersten Wise, Kentucky Extension Plant Pathologists) -



Reprinted with permission from the Kentucky Pest News, July 18, 2017.

Southern rust of corn, caused by the fungus Puccinia polysora, was confirmed by the University of Kentucky Plant Disease Diagnostic Laboratory (PDDL) this week on samples from Caldwell County and Graves County. This is the first confirmation of southern rust in Kentucky in 2017, and the impact of this finding for Kentucky corn farmers will depend on current crop growth stage.

Fields that are between tasseling (VT) and milk (R3) growth stages may benefit from a fungicide application if southern rust is present. If fields have already received a fungicide application, they should be scouted to determine disease severity prior to a second application. More details on symptoms and signs of southern rust and recommendations for fungicide use can be found in a previous Kentucky Pest News (KPN) article that can be accessed here.

If you suspect you have southern rust in your field, work with local county Extension agents to submit samples to the PDDL for proper identification. Confirmations will be posted on the Integrated Pest Information Platform for Extension and Education (iPiPE) as discussed in a previous KPN article that can be accessed here. On the map, red counties/parishes indicate that southern rust has been confirmed by university/Extension personnel.


Confirmed findings of southern rust, July 18, source iPiPE <http://ext.ipipe.org/>.

Confirmed findings of southern rust, July 18, source iPiPE .




back to top



Southern Rust Found on Corn in Indiana (Gail Ruhl and Tom Creswell) -



On July 20, 2017, the Purdue Plant and Pest Diagnostic Laboratory (PPDL) microscopically confirmed Southern Rust (Puccinia polysora) on a corn leaf sample submitted from Parke county. 

Orange spore pustules of Southern rust on corn develop predominantly on the top of the leaf—as opposed to the brownish - red spore pustules of common rust that develop on both upper and lower surfaces of the corn leaf.

For more information and images please refer to Purdue publication BP-82 : Common and Southern Corn Rusts 
https://www.extension.purdue.edu/extmedia/BP/BP-82-W.pdf.

 Although the location, color, and shape of the pustules can assist in the identification of the type of rust infection on corn leaves, if you suspect you have Southern rust in your field, submit samples to the Purdue Plant and Pest Diagnostic Lab (PPDL) for proper identification.  We provide definitive, accurate, confirmation of Southern Rust by microscopic examination of the shape and size of the rust spores.  The sample handling fee for a sample is $11.00.  Sample submission forms are available at: www.ppdl.purdue.edu.

Please feel free to contact us if you have questions.

Gail Ruhl 
Senior Plant Disease Diagnostician
ruhlg@purdue.edu

Tom Creswell
Director, PPDL
creswell@purdue.edu
765-494-8081


Southern corn rust; orange spore pustules on top of corn leaf.  (Photo Credit: Tom Creswell).

Southern corn rust; orange spore pustules on top of corn leaf. (Photo Credit: Tom Creswell).




back to top

WEATHER UPDATE




Precipitation



total precipitation


back to top



Temperature



average temperature

back to top


THANKS FOR READING




Contact Information

Purdue Extension Entomology
901 W. State Street
West Lafayette, IN, 47907
(765) 494-8761
luck@purdue.edu
@PurdueExtEnt
PurdueEntomology

1-888-EXT-INFO

Subscribe

If you would like to be alerted by e-mail when the current issue of the Pest&Crop is available on-line, please enter your e-mail address and click the submit button.

DISCLAIMER:

It is the policy of the Purdue University Cooperative Extension Service that all persons have equal opportunity and access to its educational programs, services, activities, and facilities without regard to race, religion, color, sex, age, national origin or ancestry, marital status, parental status, sexual orientation, disability or status as a veteran. Purdue University is an Affirmative Action institution. This material may be available in alternative formats.


back to top


Purdue University
| College of Agriculture | Entomology | Extension

Copyright © 2017, Purdue University, all rights reserved, site author Entomology Extension

Website developed by the Entomology Department at Purdue University
An equal access/equal opportunity university