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ABOUT ME

osunpk

osunpk

Since 2008 I have served as the Precision Nutrient Management Extension Specialist for Oklahoma State University. I work in Wheat, Corn, Sorghum, Cotton, Soybean, Canola, Sweet Sorghum, Sesame, Pasture/Hay. My work focuses on providing information and tools to producers that will lead to improved nutrient management practices and increased profitability of Oklahoma production agriculture

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Check Canola for Aphids

Tom A. Royer, Extension Entomologist

I have received scattered reports of cabbage aphids infesting canola racemes and low levels of green peach aphids feeding on canola leaves. Cabbage aphids are small, 2.0-2.5 mm (1/12 inches) blue-gray aphids with short cornicles.  They are usually covered with a powdery wax coating.  They are often found clustering on the developing panicle (Figure 1).  They can cause plant stunting, distortion of growth, and flower abortion.

File written with CompuPic(R) - Photodex Corporation (http://www.photodex.com)

Cabbage Aphids

Green peach aphids are pale green to yellow (and sometimes pink) with long cornicles and antennae and measure 1/8 inch.  They are found in winter and spring on leaves (Figure 2). Their feeding can cause stunting and defoliation. They can also transmit plant disease-causing viruses such as cauliflower mosaic and turnip mosaic viruses.

 

Green Peach Aphid OK 2013 (2)

Green Peach Aphids

Scout for aphids by looking on the underside of the leaves, and racemes. For cabbage aphids, research conducted in Australia suggests that an insecticide application is justified if 20% of the racemes are infested with cabbage aphids.

For green peach aphids, research conducted by Dr. Kris Giles at OSU found that and average of one green peach aphid per plant can reduce seed yield by about 0.5 lb per acre. Thus, if the cost of an application is $10 per acre, and canola is bringing $0.2 per pound (quote from ADM Farmer Services 04/08/2016 www.adm.com), an infestation of 100 aphids per plant would cause yield loss of $10.00 (50 lb, x $0.2/pound) which is equal to the cost of the application. This is known as the ECONOMIC INJURY LEVEL (EIL).  We typically set the ECONOMIC THRESHOLD (ET) below the EIL, in this case at 80% of the EIL (80 aphids per plant) to give time to schedule an application before the EIL is reached.  Below is a set of suggested ECONOMIC THRESHOLDS, based on the cost of the application.

Application Cost                     Economic Injury Level           Economic Threshold                                                                                     (Application cost/
0.5 lb/aphid x $0.2/lb              (0.8 x EIL)

$8.00/acre                                80 aphids/plant                        64 aphids/plant\
$10.00/acre                              100 aphids/plant                      80 aphids/plant
$12.00/acre                              120 aphids/plant                      98 aphids/plant
$14.00/acre                              140 aphids/plant                      112 aphids/plant

 

Current recommendations for control of aphids in canola are listed in CR-7667, Management of Insect and Mite Pests in Canola which can be obtained online at http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-3045/CR-7667web2009.pdf.

Transform® insecticide is no longer registered for use in canola as of November 11, 2015. Only existing stocks that have already been purchased and delivered to the grower before the cancellation can be applied according to the label.

Remember, green peach aphids have a history of developing resistance to pyrethroids, which are the primary registered insecticides for use in canola. Thorough coverage of an insecticide application is necessary to obtain optimal control.

If you notice natural enemy activity, especially lady beetles, and want to preserve their activity, keep several things in mind. Our research shows that Beleaf® insecticide is particularly benign to natural enemies because of its slow acting efficacy on aphids, which allows aphid-feeding beneficials to continue to eat them with little to no consequence on their biology.  That being said, cabbage aphid may contain toxins that they acquire through their feeding which make them less palatable to some predators, and reduces their effectiveness as natural controls.

With all pesticides, review label restrictions for applications during bloom, as honeybees can be killed if exposed to several of the registered products.  One registered product, Beleaf® (FMC Corporation) does not have any restrictions for application during bloom.

Ag Apps Updated

Since my Ag App post in July I have presented on the topic an additional five times and have two more on the books for 2014.  A good thing about doing talks is that you have to update the information to remain current.  Which in all honesty, when it comes to technology of any kind this is quite challenging and even more so for Smart Phone Apps.   In July when I first blogged on the subject I had 76 apps on my iPad.  Today (1.3.14) I have 111 apps on my iPad, for both the iPhone and iPad, that I deem to be Ag related. Since the summer I have found new favorites, changed some, and added categories but for the most part I still maintain my 2 minute rule stated in the first blog.  I have allowed a bit more leniency in that I now say “If I cannot figure it out in 3 minutes it’s GONE.  An app should be intuitive, easy to use and have a purpose.  They only exception to the 3 minute rule is the Scouting and Mapping Apps. Because of their complexity I allow them 5 minutes, and then I am done.  Any app with GIS in its name gets much more time”  I guess I am just getting soft.

Again I must make the obligatory statement; I am not a developer, designer, or expert.  I am just a user who has had a chance to look at a few apps. Almost all of the apps I have are free and I am sure I have missed a few.   Please share those with me.  I am also not discussing Mobi’s, this is another large group of quality decision aid tools.  I am also not discussing none apples apps.  This is not because they are not relevant or important, it is because I do not have that technology.

I now have nine Ag folders on my iPad:
Ag News/Weather/Markets, Scouting/Mapping, Record Keeping, ID Tools, Crop Tools, Calculators, Sprayer/Chemicals, Fertilizer, Seed Select.

Apps are nice because the majority are stand alone and do not need internet or cell connection.  This means they can be used when you are in the middle of nowhere, which is a great deal of Oklahoma, and have no service.  This will exclude many of the Ag News/Weather/Markets, Scouting/Mapping, and Record Keeping apps that need positioning or location information.

Now let’s discuss some of the new and old apps.

Ag News/Weather/Markets

news11 news2 news3

Not much change in this group however I have added one or two.

Scouting/Mapping

Scout2 Scout 1 Scout 3

This category has changed the most.  Record keeping apps have been removed and several new apps added.  The only free apps which can create boundaries are still Scout and Sirrus.  To date Scout remains to be my favorite app for in field scouting notes.  Pictures tagged with Lat Long and a note is very useful.  My knock on is app is its boundary creation.  It is a challenge every time as it is hard to remember the steps and not make a mistake.  That is where Sirrus comes to play, by far the best boundary creation app.  Sirrus has easy to use tools for both point and pivot boundaries.  I like the edit vertex zoom in tool that resembles a rifle scope.   I was able to add 12 fields in a matter of 20 minutes.  Being able to create grid soil sampling scheme and record samples is also a very nice tool.  My favorite part of the app, the UNDO button, and all apps should include this.  The drawback to Sirrus is that it has no ability to take notes such as Scout.  An additional nice scouting tool is South Dakota States NPIPM (North Plains IPM) app.  This app provides not only a pest id tool with morphological drop down, I will discuss this in the ID Tools cat, but also management recommendation for the identified insect.

Record Keeping,

records

The majority of the apps in this category are “Pay to Play”, which makes since as they deal with data management and storage.   Many would also fit the Scouting/Mapping category.  As I do not pay for many apps I do not have experience with any of these.  However this is the category that I would recommend any group to look at as they should be the all-inclusive app.  However, PeRK by the University of Nebraska is a free app designed for field records of pesticide applicators.

ID Tools,

id1 id2

I have added a few apps to this category but my favorites have not changed.  I regularly use Plant Images, ID Weeds, and the Pestbook as references.  I will add more discuss to app ID tools.  The importance of being able to ID weeds and Pest via morphological drop down menus (ID Weeds and NPIPM) is extremely important.  Many of the ID tools just have pictures and names.  Well is I am using an ID Tool I likely do not know what I am looking at or what it is called.

Crop Tools,

Crop

Crop Tools includes my second “Paid in Full” app.  And this one hurt a bit more.  Not because it cost money but because I have multiple versions of the hard copy.  However Field Guide by Purdue is one of my most recommended apps.  Field Guide is the electronic version of the Purdue Corn and Soybean Field Guide, which the majority of consultants in the Corn Belt likely have this sitting in their truck.   The Stoller apps also have nice very nice image bank of plant developmental phases.  FieldGuide and CornAdvisor, another good app, are great examples of what I expect to be coming out of the majority of the Land Grant Universities very soon.   Cooperative Extension has hundreds if not thousands of quality hard copy publications just waiting to be turned in to handy dandy apps.  To be honest I am working on turning my Nutrient Management Field Guide into an app right now.

 Calculators,

calc1 clac2

Only two apps has been added to this category.  I am still using Fert.Removal, HarvestLoss and Growing Degrees on a regular basis.

 Sprayer/Chemicals,

spray1 spray2

Many apps have been added to this group but none of them have been good enough to kick TankMixCalc and SpraySelect of my favorites list.

 Fertilizer,

fert1 fert2

Similar to the Sprayer/Chemicals category several apps have been added to this group, including several from Ok State.  For me the Fert Cost Calc is still very useful.  I do not get to use the Manure Calc I am very impressed by its layout and user friendliness.  This app allows for applicator calibration, nutrient recs and manure value estimator.

Seed Select,

 seed

It is no surprise the apps in this category are company created.  I will say for the central Great Plains Pioneer’s Canola Calc is very useful tool for selecting canola planting rate providing input for row spacing live plants, seed weight, Germ percent, and survival percent.

To wrap up this blog I want to share with you may new Favorite none ag app.  Bump is a huge time saver for anyone who takes pics with your iPhone or iPad.  Bump allows easy transfer between mobile devices but more importantly between your mobile device and desktop by a simple tap of the space bar.  This file share will go both directions.  This means no more emailing pictures from your phone so that you can have them on your desktop.  Bump is a iPhone app that can work on the iPad.

When searching with an IPad, remember to switch the search to include IPhone apps, there are some good ones out there that are IPhone only.  Check out www.npk.osktate.edu/presentations  to see screen shots from many of my favorite apps.