Hail – Hell on Crops

They’re violent, loud, dangerous, destructive and often are precursors to tornadoes. Hail storms. The average hail storm lasts less than a couple of minutes but depending on the intensity and size of hail stones, damage can vary from barely noticeable to total crop destruction.

A healthy and complete crop canopy provides the highest yield potential for growers.

Hail damage to crops basically comes down to these questions – will the plants survive and, if so, will yield be affected? In my experience, more so for corn, the most noticeable effects of hail damage are three-fold: twisting of the leaf canopy, leaf loss, and stem bruising.

Twisting of the leaf canopy is the result of leaves being shredded by hail stones with the shredded remnants being wrapped or twisted by excessively strong winds. (This phenomenon is more prevalent in young corn, usually V6 or smaller.) The reason this can impact plant survival is that the newly emerging leaves in the whorl can’t advance as the plant recovers. Survival rates of plants can improve if the dying, twisted leaves can somehow detach from the plant, making emergence of the new leaves possible. The impact on yield depends on plant death (stand loss) and distribution down the rows (plants that recover quicker can shade out and out-compete adjacent plants.)

Leaf loss is the most obvious effect of hail on plants. The leaves are the photosynthetic factory – capturing sunlight and converting it to energy that supports plant growth. Believe it or not, there are times when complete leaf loss will not impact yield. Such is the case in corn where leaf loss up to about V3 is not detrimental. Reason being, this is before ear development commences and the plant is still dependent on the seminal root system for support.

A healthy corn canopy (left) compared to one after a hail storm (right).

An excellent chart on the effects of leaf loss on corn yield can found in the University of Nebraska publication: http://extensionpublications.unl.edu/assets/pdf/ec126.pdf. This is my go-to extension publication on this subject and it includes examples of various field situations. For a discussion on hail damage effects on forage/silage quality: http://corn.agronomy.wisc.edu/Management/L039.aspx.

Whorl or stem bruising is often overlooked in assessing hail damage. Hail stones are dense and hard. Young corn plants, however, are tender – very little lignin formation has occurred and so a somewhat rigid stalk rind has yet to develop. As the winds bend over the stalks, the lower sections are exposed and vulnerable to being struck by hail stones. The thing to remember is that the growing point is near or above the soil surface around V5 or V6. If the stone penetrates deep enough, it can bruise and kill the growing point. When this happens, the plant is finished. A sharp knife (and the appropriate protective gear) can help determine the depth of penetration of a hail stone. The growing point should be near white while a damaged or dying growing point will turn brown.

Hail stone bruises on the lower stalk.

For a discussion of hail damage on young corn, I highly recommend this site, authored by Dr. Robert (Bob) Nielsen at Purdue University: https://www.agry.purdue.edu/ext/corn/news/timeless/HailDamageYoungCorn.html

As with most storm events, its too wet to do anything in the field afterwards so the best advice is to wait and assess plant recovery over a period of about a week. Give the plants time to recover! In the meantime, don’t hesitate to call your seed rep and agronomist and get their opinion. Here are some other resources for various crops:

Soybeans: https://crops.extension.iastate.edu/files/blog/files/Hail%20Damage%20Assessment%20to%20Soybeans.pdf

Sorghum: http://extensionpublications.unl.edu/assets/pdf/ec129.pdf

Cotton: https://arizonaipm.files.wordpress.com/2013/06/assessing-cotton-yield-loss-to-hail-damage-in-southern-arizona-2011.pdf

Alfalfa: https://cropwatch.unl.edu/managing-hail-damaged-alfalfa

Sunflower: https://www.ag.ndsu.edu/pubs/plantsci/rowcrops/a1331-09.pdf

Gardening: https://www.denverpost.com/2019/06/11/garden-hail-damage-tips

As always, I want you to do well. ~ph.

Goodbye to a Hybrid

An Essay on the Rise and Fall of Hybrids in the Seed Business

Since the beginning of hybrid corn development in the early 1900s, breeders have made step changes in product performance.  (A step change is where the new hybrid is not just a little better than the previous generation of products but so much better that growers will demand only that hybrid.)  These changes might encompass significant improvements in disease tolerance, lodging or insect resistance and of course, yield.  Sometimes the step change is extraordinary.  The seed industry has seen this over the years where a hybrid performs at such a high level that it takes traditional breeding programs literally years, sometimes decades, to catch up to it.  Pioneer Hi-Bred has a wonderful history of these, most notable being corn hybrid Pioneer® brand 3394 (early 1990s) and sorghum hybrid Pioneer® brand 84G62 (late 1990s).

Understandably, growers can become emotionally attached to these extraordinary hybrids.  After all, their success is tied to the performance of the products they plant.  Yes, it’s mostly yield that drives this success, but not just yield in one year – yield across multiple years.  In the seed industry, we describe a hybrid that yields consistently over time and across environments as “stable.”   As an experienced agronomist with over 20 years of experience, stable hybrids are few and far between.  These are the hybrids that growers request for many years knowing that the hybrid will perform and that they won’t have to worry about whether the latest and greatest new product will let them down.  In a business that’s often “year to year,” this stability is often welcomed.  It’s peace of mind.

Unfortunately, or fortunately, depending on which side of the ledger you’re on, stability is not always the driving factor in selling hybrids.  It’s no secret that seed companies will literally introduce and drop a hybrid after only one year.  This speaks to the rapid improvements in breeding science but also the drive for yield and financial success in a very competitive market place.  So, hybrids that are stable – meaning, not always winning the yield contest but certainly above average – are not always in demand.  This makes life difficult for a seed company in deciding what to grow for the next selling season.

After harvest, a seed company must decide what hybrids to produce the following summer in order to have the seed supply needed for their customers to plant in the spring more than a year later.  To do this, they must predict what hybrids their customers will likely buy for the following year.  But growers often base their purchase decisions on the current year’s performance and don’t always consider previous years.  Weather plays a key role in product performance but no two years are alike and the best hybrid this year might not be the best next year.  As you might imagine, it’s very difficult to predict which hybrids will perform best when you don’t know what the weather will bring!  Given this, stability seems like a good thing, doesn’t it?

The complexity of growing hybrid seed is nearly overwhelming.  Below is an example of a corn hybrid that’s widely adapted (image courtesy of Pioneer Hi-Bred) that literally has 221 variations.  For this hybrid, there are nine versions of trait offerings for various market opportunities.  A few examples include a “conventional” version – no traits for the organic market; an herbicide tolerant version – no insect traits but needed for refuge acres and a below-ground insect protection version for areas with known corn rootworm pressure.  Next are seed treatments – various rates of insecticide, formulations, active ingredients, etc.  Then there are several packaging options of which the most common are boxes and bags but imagine various sizes of these units to accommodate field research needs.  My personal favorite is the last tier which is seed size – rounds and flats of which there are small, medium and large.  Depending on the hybrid, there can also be extra small and extra large.  Today’s high-tech planters can often be fickle about seed size.  Take my word for it, you can have all the right genetics, traits, seed treatments and packaging but if you don’t have the right seed size for the planter, you can lose the sale!  Seed size is mostly determined by genetics but can be manipulated to a certain degree by management.  Historically, hybrids have been dropped because they consistently produced seed that was either too small or too large.

This complexity in seed offerings for the grower has value.  A seed company is a business and assigns a cost to every one of the 221 variations in this example.  It must do this to keep track of production costs and understand what “value” each variation contributes to the overall picture.  So, what happens when a hybrid doesn’t perform to expectations and growers decide to move on?  Demand drops and now the cost of producing these variations starts to increase.  (Imagine growing seed based on demand that fizzles for one reason or another – you now have a bunch of processed seed sitting in storage that nobody wants.)   Again, this is a business.  Just as every company assigns a cost to each variation, they also assign a threshold cost where it doesn’t make sense to continue producing it.

As you observe sales of seed over time, you’ll notice that all hybrids have a “lifecycle.”  If they make the cut after the first year, sales grow for a time (they’re new and exciting), then stabilize (above-average but starting to fall behind), then drop (stable yield but just simply getting left behind by newer genetics).  Not long after the final stage, they are no longer produced.  The decision to drop a hybrid is not easy.  Typically, near the end of a hybrid’s lifecycle, production acres (the production fields where the male and female inbreds are grown to produce the hybrid seed) become more difficult to manage (small acreage needed at this point) and variability in production per acre tends to go up.  Thus, production costs also go up. 

Finally, regional differences (a hybrid does well in one area but not others) can often accelerate a product’s lifecycle.  This, honestly, is the demise of most hybrids in the industry.   When a hybrid is widely adapted –  grown on a lot of acres by a lot of producers – the production process is more efficient and frankly, more profitable.  But when demand drops quickly, as might be the case when a large growing area completely walks away from a hybrid, a decision to keep producing that hybrid must be evaluated even knowing that it might still be one of the best performers in other areas of the country. 

The seed business is complex, business-driven and very emotional.  Emotions around a hybrid can be strong as growers gain an affinity for something that feels like family.  Livelihoods thrive on the success of hybrid seed production and seed company employees often feel equally emotional at the loss of hybrids.  Given all of this, there’s an axiom about the seed business that I often share with customers: “Don’t fall in love with this hybrid. There’s a good chance it’ll be gone next year.”

I want you to do well. ~ PH