Thresholds in Crop Scouting

 We are quickly entering the spring season, when planting is on the mind, and we start thinking about weeds and pests. Our anxiety rises when considering treatment options for the critters out there who want to eat or crowd out what we are trying to grow for our livelihood.  I thought it was a good time to review just why it is a good idea to have a professional out there looking at your fields, and why, sometimes, they don't recommend doing anything, even when you think you see something that worries you.  Read on! 

Thresholds in scouting

Why we don’t always treat when we see a problem

When I scout a field, I look for anything out of the ordinary during the growing season.  Each part of the season brings a new set of challenges.  Early on, there are weeds to consider, emergence problems, and seedling diseases.  Later in the season, I look for nutrient deficiencies, insect feeding, and root and foliar diseases.  I look for damage from wind and drought. 

When I do see something that is out of the ordinary, I don’t always recommend acting on it.  I’m not just looking at insects for the opportunity to spray insecticides, and I’m not going to tell the producer to find a fungicide whenever I see a disease. 

Why is that? 

There are several reasons. 

First, there isn’t always something we can do about the problem.  For example, if there’s a water shortage or a drought in a dryland or rainfed field, I can note the leaves curling and plants wilting, but there’s no pivot to turn on.  All we can do is hope for rain.  In another case, there’s a relatively new pest haunting soybeans in my area called the soybean gall midge.  We have a couple years of research on this the little fly-like creature, but the adults spend their time in the ditches and woods surrounding the fields and only come into the fields to lay their eggs.  Once they hatch, the larvae, which are barely visible to the naked eye, quickly find cracks in the stems to hide away, burrowing into the interior of the plant.  Neither the adults nor the larvae would be affected by an insecticide treatment in the field—the adults aren’t in the field for very long, and the larvae are too well protected by their burrowing habits.  So alternate and preventative treatment considerations are being discussed.  For now, we observe and report. 

Second, it isn’t always the right time of the year to treat the problem.  I recently saw some corn plants with yellow whorls and interveinal chlorosis.  This definitely could be the sulfur we had yet to apply to the field, but more likely it was due to a pH problem.  When the plants are in the field, it isn’t the right time to be applying lime to correct the pH.  So, again, we can apply the sulfur, but have to schedule the lime for after harvest in the fall or next spring before planting.  Alternately, the problem could be larvae that had eaten their way through much of the vegetation, but most of them were already in pupae—they won’t be eating anything as adults, so it doesn’t warrant treating pupae who won’t respond to the insecticide.  Also, just because you see evidence of feeding on plants, doesn’t mean you see the critter that has been feeding on them—you may be treating a critter that isn’t even there anymore. 

Third, the problem isn’t always at the economic threshold to be able to warrant treating the problem.  No field is going to be perfectly pest-free, and no plant is going to be perfectly free of some sort of feeding or disease.  Universities come out with what they call “economic thresholds”, or the point at which a pest is going to create enough harm to the plant that yield will be adversely affected, and the extra expense of treating the field is worth it.  Not only are you paying for the chemical, but there’s the application fee if someone else does the application, and equipment cost, fuel, and time spent driving in the field if you do the application yourself.  The potential income from yield lost has to outweigh the cost to treat the pest.  In the case of insects, it may be number of insects per plant or amount of total feeding on the plant (percent of defoliation), in which every leaf on the plant is considered for total loss.  In the case of diseases, it may be percent of the field affected by the disease or number of lesions on each plant. 

Sometimes, scouting a field is more of an art form than a cut and dry numbers game.  Just because you see the critter out there—or even the evidence of it, doesn’t automatically mean there is something that can or should be done about it.  But that also doesn’t mean you shouldn’t be out there watching things grow, and keeping an eye on things.  Because the moment that threshold is crossed, and the season is right, timing is of the essence.  It helps to have someone that knows what they are looking for, and knows what they are looking at. 

It helps to have someone outstanding in the field.  [Yup.  I had to throw that pun in there.] 

Who’s looking out for your crops?

Thanks for reading.

Julie S. Paschold

originally written June 16, 2020

repost April 17, 2023

Danger: Don't Drink This

 

Danger: Don’t Drink This

or How stupid are we?

Responsibilities in wise chemical use

This is a repost from early 2020, when RoundUp was facing lawsuits.  It is still a good read today, about being smart when using chemicals, or anything that could possibly damage you.  My son and I had a good conversation about pocket knives last night.  A pocket knife can be used as a tool for many reasons (a good agronomist is never found without one), but it could also be used as a weapon, so they are banned from some college campuses and in your carry-on in airports (I found that one out the hard way). It is also a good laugh about the silly warnings companies put on their labels. It will make you go out looking for more.

I was minding my own business, chilling in my living room with the television on.  I frankly don’t pay much attention to the “boob tube”—I’d rather be doing something like reading, sketching, walking, putting together a puzzle, talking to my kids, or making up horrible puns with my dad.  

[Okay, I have to interrupt this blog for a good one: my parents were on vacation, walking along the beach, counting jelly-fish.  Being a midwesterner, I had no idea that they just wash up on the shore and lay there on the sand, so my dad took a photo of one and sent it to me.  His caption:  “A picture of the marmalade-fish”.  Ha.  Here’s the little guy now (the fish, not my dad): 

So I responded—“If you see any with a guitar, I guess it would be a jam-fish, then, wouldn’t it”.  Double Ha!  …Come on, didn’t I at least make you groan?]

Back to our regularly scheduled program.  I’m barely paying attention to the channel, glance up, and there’s this lady with GIGANTIC eyes telling me that I quite likely am on my death bed if I’ve even come near the weed killer RoundUp, and need to call her number immediately to be connected to a lawyer who can include me in a lawsuit for damages, but I need to call NOW because there’s no time to waste!  [Frankly, her scary face is what might lead me to my death bed—there’s so much make-up on there and her eyes are pasted so wide open, I thought the color in my TV screen had gone wacky!]

If any of you have watched or read any news, chances are you have heard about EPA’s recent reexamination of studies related to the active ingredient in RoundUp, glyphosate, and whether or not it causes long term health problems.  The latest decision from EPA is that, if used as labeled, there is NOT proof that glyphosate causes cancer. 

But people are still scared—and skeptical.  The ad I saw is one example of how lawyers play on that fear, and the line between facts and rumors becomes hazy. 

This got me thinking.  I agree labeling, restrictions, studies, research, guidelines, and regulations are all very helpful and absolutely needed when using any sort of chemical anywhere.  If we didn’t have guidelines on rates, times of day, temperatures, wind speeds, cautions to stay away from wildlife habitats and being aware of those cute little honeybees, we’d be in trouble.  And the definition of chemical can be so loosely and diversely applied, that it’s a subject for another debate altogether.  However, where do we draw the line between putting the responsibility on the chemical manufacturer and using our own common sense when utilizing their product? 

Remember the woman who sued McDonald’s when she burned her skin spilling coffee on herself?  How silly was that—you ordered coffee, coffee is hot, you spill coffee, hot coffee can hurt.  Common sense, right?  Why does there need to be a warning label for a natural consequence that an average person would understand?  Have you ever read the warnings in the fine print on some other products?  For example, on my sleeping medication, it warns me “may cause drowsiness”—well I should hope so!  That’s why I’m taking it!  And on a department store stroller, in order to not forget your child is in there—to place something valuable in the stroller as well, so you don’t forget to remove your child [Um, isn’t your child probably the most valuable asset you have?]  On skin creams, to not ingest.  On carpentry drills, to not use as a dental drill.  Or the advice to not eat those little silica gel packets [but they look so yummy!].  On saws, to not grab the blade when it’s running.  On thermometers, to not use it orally once you’ve used it rectally [ewwww].  Reminders to not operate machinery while unconscious or sleeping [I didn’t even know that was possible].  The fact that the manufacturers had to put these specific warnings on their products is an indication that someone has actually tried it at some point in time.  Blows your mind, doesn’t it. 

Back to our herbicide.  I’m not saying there isn’t proof that glyphosate doesn’t cause cancer at all in any circumstance.  But just because using glyphosate as labeled doesn’t cause long term health problems doesn’t mean I’m going to put it in my morning coffee or bathe in it.  Any chemical intended to kill something isn’t meant for us to breathe in or be exposed to in large quantities—isn’t that common sense as well?  Obviously not, because Bayer is still facing lawsuits.  I talked to a gal last night who used to work for a tree nursery.  She told stories about how they would get phone calls about people calling about their sick trees, and come to find out the individuals had sprayed weed killer around their actively growing trees.  [You didn’t think about the fact that a tree is a plant?  And weed killers are designed to kill plants?]   

The public scare is growing to the point that Bayer is considering removing RoundUp as a product available for private users.  So no more spraying your rocks or driveway or garden with glyphosate.  I understand the scare about chemicals causing health concerns, but I also understand the move towards taking the chemical away from the common citizen.  It’s better to be safe than sorry, and prevent more people from ending up like the gal that spills hot coffee on her lap and can’t believe she got hurt. 

I guess sometimes even a warning label can’t fix things. 

 

Thanks for reading!

 

February 25, 2020

Julie S. Paschold

Does Your Soil Have a Hangover?

 

Does your soil have a hangover?

An exploration into soil health

The result of being a two-time graduate of the agronomy program of the University of Nebraska-Lincoln, spending many hours as an undergraduate at the soil fertility research program working with Dr. Dan Walters, and slaving away at my graduate work with the USDA-ARS Soil and Water Conservation Research Unit associated with the agronomy department at UNL is that I have been lamenting the loss and retirement of many of the professors that taught me—the UNL soils team that was once so abundant seems to be sparse at the moment.  It is going through growing pains, awaiting reestablishment of its shaken foundation.  The Crop Production Clinic in Norfolk in 2020 was mostly geared toward pest management.  So when I saw an opportunity to view a soils presentation online given by a Lancaster County Extension Soils Specialist, I grabbed the chance.  Could there be hope? 

Aaron Hird spoke of soil health, and he used a good metaphor.  If he doesn’t mind, I’m going to “borrow” that idea and run with it.  Soil health is defined as the continued capacity of the soil to function as a vital living ecosystem that sustains plants, animals, and humans. 

If you think of the soil as a body, then how do you take care of its health? 

Well, how do you take care of your own body? 

If you ate junk food, didn’t exercise, sat behind a desk all day and stared at a computer or laid on the couch and watched television or played on your smartphone constantly, how would you feel?  If you drank sugary drinks instead of water and ate only processed foods, how would your body respond?  You’d feel pretty cruddy, huh?  The more yuck you put into your body without building muscle, the more fat you will acquire—and the less energy you’ll have.  It doesn’t matter how much you sleep.  If you don’t put good stuff into your body, you won’t have the energy to do anything.  So your body will crave energy, but if you keep giving it the wrong stuff, it won’t use the food efficiently and won’t find the proper nutrients it needs.  You’ll get hooked on caffeine, eat more crap, and it’s a never-ending cycle. 

It’s the same thing with soil.  The microbes and plants living in the soil have certain requirements to stay healthy and living—the soil needs to eat healthy, too.  That’s why we soil sample and apply the correct fertilizer for the crop growing there each year.  But fertilizer isn’t enough.  You know how you feel when you wake up after a late night partying?  That’s kind of how the soil feels if you take too much out of it without putting the right stuff back.  Yeah, your soil’s going to get a hangover.  And just adding a bit of fertilizer doesn’t do the trick.  That’s like taking a vitamin and expecting to go back to normal.  That wouldn’t work for me! 

Soil needs the proper balance of air circulation, water, nutrients, ability to maintain and build structure, create habitats for microbes and other critters—a whole gamut of health considerations!  If you look at that list, it doesn’t look much different from ours—we need to breathe, drink, eat, build and maintain bones and muscles, and protect the microbiome in our gut, too. 

So when you are making your field plans this year—or just out tinkering in your garden or yard—please consider all of your soil’s needs!  It will thank you later, and you will reap the rewards. 

Thanks for reading!

 

February 5, 2020

Julie S. Paschold

Reference: Nebraska Extension in Lancaster County’s Successful Farmer Series, January 31, 2020: Soil Management:  https://lancaster.unl.edu/ag/successfulfarmerseries

That's Just Not Natural

 

That’s just not natural

Tricky advertising and common instincts in plants

 

I was walking down the produce aisle in my grocery store last week, grabbing the items from my shopping list derived from my planned menu for the upcoming few days.  I had sent my son on a mission for yellow onions, and I was going to look for fresh broccoli.  As I turned and looked up, a package caught my eye.  A bag of organic lemons.  They weren’t on my list, and I don’t find it necessary to pay extra for the fancy “organic” word—those are expensive letters!  What caught my eye wasn’t that they were any better than the regular lemons—there was no visual difference, actually.  It was the wording on the package.  I was so amused that I laughed out loud, and even pulled out my phone to snap a photo:

[First of all, a short comment about the “non-GMO”.  Yeah, so your lemons weren’t beamed down from the Starship Enterprise and created from an alien species.  Well, good for you.  Ha.  Not going into that with this blog.  And I definitely wouldn’t pay extra for those words to be printed on a package, either.]

What I laughed about was the “naturally seedless” part.  Have you heard people say the word oxymoron?  Then go on to use the phrases such as “jumbo shrimp”, “wise man”, “unbiased opinion”, and “genuine imitation”?  Well, folks, add “naturally seedless” to the list. 

What is Mother Nature’s one goal for EVERY SINGLE PLANT on this earth, regardless of where it is grown, why it is growing, how long it grows, or what it looks like?  For that matter, Mother Nature’s goal for every living species on this earth…….

……is to reproduce. 

A lemon is a fruit that grows on a tree.  A fruit is “a ripened, thickened ovary of a flower, which protects dormant seeds and aids in their dispersal”, according to my college Biology textbook. 

So every time you bite into an apple or an orange or a squeeze a lemon, you’re handling someone’s ovary.  Yup.  You read that right.  Plants have ovaries, just like people.  The seeds are their babies.  Mother Nature intends for each plant to develop progeny; that is why each lemon tree develops fruit with seeds—so little trees can emerge and take over when the parent tree gets too old. 

So a lemon without seeds?  That’s just not natural. 

 

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If a plant has an ovary, it means it has to get fertilized, right?  I mean, we were all taught about the sperm and the egg.  You can’t have a baby without both.  So if the fruit is the ovary, what the heck is the plant’s sperm? 

Well, ahem, do you sneeze a lot during the times that flowers are wide open and blooming?  Have you heard someone say they have “hay fever”?  Do you have to brush off yellow stuff when dancing through the daisies and prancing through the posies?  The sneezing is your irritation from the yellow stuff, which is pollen.  The pollen comes from stalks in the center of the flowers—and they are little tiny specks that float around, on a mission.  They are the plants’ sperm.  So that means you’re breathing in plant sperm on those fresh air walks.  [I’ll give you a moment to get over your heebie jeebies here.] 

Once a pollen grain finds the right place, it fertilizes the ovary, the flower dies, and the fruit is created, with the seeds inside. 

 

***************************************************

 

So what happens when the plant is stressed, dying, or somehow in trouble?  A plant will perform amazing feats in order to make its babies.  Even change genders. 

On a corn plant, the ear growing protected in husks lower on the side of the stalk is the female part of the plant—the kernels are the babies.  The male part of the plant is the tassel on the top, which creates all the itchy pollen that flies all over the place (including down your shirt, if you’re so unlucky to have to walk through a corn field during pollination).  If a corn plant is damaged somehow, like stepped on, cut off, drowning, sprayed with the wrong chemical, in a storm, or missing nutrients it needs, chances are the ear didn’t develop properly.  In that case, since pollen is a dime a dozen and it can get away with creating a tiny bit of its own and receive pollen from its neighbor, the stressed corn plant will change its tassel to become a partial ear. 

Just to prove I’m not pulling your leg, here’s proof:

 

I call it transgender corn.  Kinda neat, huh? 

 

 

Wow.  So it is more “natural” for a plant to be transgender than seedless!!!  

Yet another demonstration of why you shouldn’t believe everything you read in advertisements. 

 

 

 

Thanks for reading!

 

December 30, 2019

Julie S. Paschold

Reference: Biology: Concepts & Connections by Neil Campbell & Jane Reece & Larry Mitchell. 1994. Benjamin/Cummings Publishing Company, Inc. Redwood City, CA

Beyond the Horizons: Eating Your Soil

 

Beyond the Horizons—Eating Your Soil

Do you really understand what is under your feet… and what it took to get it there?

 

When I was young, I didn’t ponder on the purpose of that dark stuff under the grass.  It was something that got stuck under my fingernails and was fun to dig up and find bugs in.  It was everywhere—even in the house, if you didn’t wipe your feet. 

So when I opened my textbook on my first day of Soil Science 101, I was nervous.  I knew that there was more to soil than a block of dark matter that held roots and water.  I barely knew anything about farming, much less the intricate details of the teeming ecosystem underneath the crops I was learning about. 

But you know what?  The book actually had some familiar words!  Soil really isn’t that different from you or I in some regards, believe it or not. 

In my first blog, we established that soil is NOT dirt, and that dirt is soil where you don’t want it.   

But what is soil?

Soil is the natural medium for the growth of land plants. 

Therefore, not all of earth’s land surface is covered with soil.  If it can’t grow plants, it isn’t soil.  What isn’t soil?  Polar ice, high elevation areas, hardened lava, salt flats, and bare rock mountain slopes.  If an area has anything that would make a plant recoil its little roots and say “Nope, not going there”—that is not soil. 

Sounds simple, right?  Well, enter NASA and explorers asking about mineral substrates on other planets.  Have you read or seen “The Martian”?  Is that soil?  It isn’t on earth….is oxygen required to make something soil?  I’m not going down that path—that’s for another day and another argument. 

Where did soil come from?

Well, where did YOU come from?  Your parents, right?  Soil has a parent, too—the substance from which the soil was made is called its parent material.  Most soils came from minerals and rocks.  Parent materials go through chemical and physical processes called weathering over many, many years to create loosened material.  In this case, weathering doesn’t mean a soil is checking the radar or the forecasted high temperature.  It means a rock is being worn down into something useful to a plant.  So your mom isn’t the only one who is worn down.  And mom?  Next time you’re frazzled, you can say you are being weathered!  Ha! 

Why aren’t all soils the same?

You may have noticed that not all soils look alike.  Some are deep, almost black, crumbly, and grow just about anything.  Others are light tan, grainy, and seem to blow around too much.  Some soils are red, some salty, some deep, some barely there.  How a soil forms depends on these factors:

·         Parent Material: You aren’t the only one who inherited things from your parents!  Properties such as rates of weathering, nutrient composition, and particle size depend on the substances that the soil came from. 

·         Climate: Precipitation and temperature are the main things in a climate that affect how a soil develops. 

·         Biota: This is a fancy word for living things and their waste, including dead parts and poop of plants and animals of all sizes—even the ones you can’t see. 

·         Topography: This is how the earth’s surface is shaped.  A soil will be affected by how level or sloped the land is, elevation, and even what direction the soil is facing on the slope (does it see lots of sunshine, or is it hidden from the light and heat?). 

·         Time: A soil can take 200 to thousands of years to develop. 

What does a plant need from soil?

So if soil is a medium or substance that can grow plants, what is needed in order to call it soil?  Soil provides the following growth factors to plants:

·         Support: No, not positive affirmations, or tight pantyhose.  Plants need help standing up, and soil provides support as the roots grow into the substrate. 

·         Oxygen: It’s often misunderstood that a plant only gives off oxygen.  It is true that oxygen is a product of photosynthesis, but a plant also needs to breathe, and oxygen is required for this.  Roots need oxygen in the soil.  Little tiny spaces between the loosened parent material hold air that contains oxygen. 

·         Water: Part of those tiny spaces between soil particles hold water, too, and the roots absorb the water as they need it. 

·         Proper temperatures: The roots can’t freeze or fry.  Temperature requirements depend on the species. 

·         Nutrients: Plants require 16 nutrients, 13 of which are supplied by the soil, either by sticking to the soil particles themselves or being dissolved in the water in the pores. 

A soil has layers?

Nope.  And yes.  But read on. 

First, you have the weathering, or creation of small particles.  Then, you have soil development.  These two put together are called soil formation.  It doesn’t all happen at once.  If you dig a deep hole, from the top all the way down to the parent material at the bottom, you would see what looks like layers of soil.  But they aren’t layers. 

Layers are for cakes.

Don’t eat it.  It’s not a cake. 

These areas of variation are called horizons.  The horizon with the least amount of formation will be at the bottom, and the most developed horizon that will grow the best plants will be at the top. 

What kind of horizons are present depends on where you are.  Most soils in my area, the midwestern United States, have an A horizon (the topsoil, where you would find the roots and the most critters crawling around and where a farmer would till and plant crops), a B horizon (a little less developed than the A horizon), and a C horizon (resembles the parent material, but has started to break down).  There are many versions, amendments, subgroups, and additions to this basic idea. 

I can friend a soil on Facebook?

Ha.  Caught you there.  You know when you see someone that is particularly good looking from the side, and think, “nice profile”?  Well, a soil has a profile, too.  Does that mean it can fill out information on Instagram and post silly photos and quips? 

          “The earthworms are tickling me particularly vigorously this morning”

          “This rain is really bringing me to field capacity”

I heard you groan. 

We were just talking about the soil’s profile earlier and you didn’t even know it.  Remember that hole you dug from the top of the soil all the way down to the parent material so you could look at the horizons?  The collection of horizons is the soil’s profile.  A soil profile is a vertical section of the soil through all its horizons and extending into the parent material. 

 

Now that you’ve become a little more familiar with soil, I hope it makes you feel more grounded.  (You’re supposed to laugh here). 

And I hope since you learned that soil has a parent that it has worn down just like you, you’ll feel a little closer to it.  So the next time you see its profile exposed, you can tell it, “Gee, I like you’re A horizon”.  (Ahem….laugh again, please). 

 

Thanks for reading!

 

November 8, 2019

Julie S. Paschold

Reference: Soils in Our Environment by Raymond W. Miller & Roy L. Donahue. 1995. Prentice-Hall, Inc. Englewood Cliffs, NJ