Hoegemeyer - the right seed

Hello from the Eastern Region! Planting seems to be winding down with many growers finishing up soybeans by the end of the week. It truly is astonishing at how fast our crop can go in if given 10 days of favorable planting conditions. Corn emergence and overall field stands look good considering the temperature roller coaster that we were exposed to in late April. A few fields had reduced emergence from temperature imbibition chilling but nothing really out of the ordinary. Black cutworm larva activity seems to remain low for the most part with only a few fields requiring treatment but fields still need to be monitored for the next couple weeks. White grub activity seems to be increasing a little each year. No rescue treatments provide reliable control for this pest so the best advice is to remember any problem fields for the future as a preventative insecticide at or before planting may be justified.

Corn imbibition

Black Cutworm Tunneling into Base of Stalk 

White grubs feeding on corn roots below ground

Some reports of purple corn have been reported in Missouri. What causes this? Purpling of corn is evidence of a couple of things. For one, some corn germplasm just tends to exhibit more purple color as seedlings than others. But for those fields with significant visual purpling it is usually due more to environmental stresses like wet soils, compaction, cool temps, and others. The plants produce a larger amount of anthocyanin pigment under these conditions causing purpling. Restricted seedling root growth can also hinder the plant from phosphorus uptake as well. Typically most of these plants will recover with minimum yield loss once good growing conditions set in unless the symptoms are very severe.

Purple Corn

The last of the Hoegemeyer research replicated corn and soybean plots went in the ground May 14th compared to June 6th last year. What a difference in planting seasons! It is worth noting that growers should be aware that we are well ahead in terms of heat unit accumulation this year. Many insect species are showing up ahead of normal time frames. This may alter when and if they migrate into crops as food sources.  In general, a younger crop is more susceptible to insect injury than a more mature crop.
Now is the time to check fields for emergence and stand counts. Don’t assume that field off the beaten path is fine. Crusting of soil can form quickly with high temps and windy conditions, especially if the field was slightly damp at planting. It is only the middle of May so we are still in a window where any replant will be able to at least approach 90% of optimum yield potential, but the clock is ticking and each day now we lose significant bushel potential. Sunlight drives yield in our crops and delayed plantings will not be able to utilize full photosynthesis potential, especially as you move north where the growing season limits us.
 

DID YOU KNOW???  The state of Alaska is famous for being able to grow tremendous vegetables.  Cabbages get as big as beach balls with a record of 100 lbs. How is this so?  The trio of fertile soil, cool to moderate temperatures, and SUNLIGHT!  At one point during the growing season Alaska has close to 24 hours of daylight. This makes for one incredible photosynthetic factory!
 

This year’s abnormally warm spring has allowed for Mother Nature to speed up the spring development of the landscape.  Trees and flowers bloomed early and insects got off to a jump start on their life cycles.  With these early developments taking place in nature, farmers were close to follow getting crops in the ground at an incredible pace and well ahead of the norm.  Overall things have gone well and farmers have been catching the warm weather they had hoped for resulting in good emergence.  However I have noticed corn imbibition in some fields causing minor stand losses of 1-4%.  Imbibition is caused by warm soil temperatures which germinate the seed, but a cold snap keeps the above ground temperatures cool enough to cause the emerging seedling to start growing downward to warmer soil temps.  After a few of these cool/warm cycles on emerging seed, a corn plant can look like a twisted up knot (see image below).  In some cases many of the seeds will germinate and outgrow these imbibition symptoms allowing for a few seeds with less vigor to meet their eventual fate, minor imbibition in a field typically does not affect yields.

Warmer than average temperature has also caused wheat to jump out to an unbelievable start.   Wheat has been headed out for weeks in Kansas, Missouri, and Oklahoma.  Many farmers are talking about harvest being 3 to 4 weeks ahead of schedule with moisture to spare.  This outlook for a very early harvest is increasing demand on soybeans for double cropping behind their wheat, harvest may even be so early soybeans planted are almost  a second crop.  While observing the phenomenal growth in wheat, I have noticed some Wheat Streak Mosaic Virus (WSMV) in Kansas.  Most commonly the WSMV infects wheat in early spring by feeding pressure from aphids which carries the virus in their saliva.  Wheat that is infected in the spring typically does not severely affect yields.  Unfortunately, fall infected wheat fields can have a drastic reduction in yield; this is commonly caused by WSMV transmission during the fall when wheat is emerging. The best way to steer clear of WSMV is to plant varieties strongly resistant to infection from the virus.

In corn, every one thousand in plant population lost in a field may mean 6, 7, 8 bushels or more in yield loss in the fall.  Bean population loss adds up too.  Seed treatments, traits and chemicals can help preserve the planted population but it is still very important to check those fields as the crop emerges and beyond.  Here are a few potential insects to look for early this spring. 

1. Wireworm: Major crop losses are to corn and small grains. The larvae live and develop in the soil. They injure plants by eating the newly planted stems, and by boring into stems and roots.

2. White Grub:  In the spring, the grubs move toward the soil surface to feed on plant roots, including roots of both corn and soybeans. They continue to feed throughout the summer.

3. Cutworm:  There are several species of cutworm and all of them can do damage, or worse, to the crop.  Early instars of cutworm feed on leaf tissue and resulting damage may be hard to spot.  Cutworms can move under the soil surface along the seed furrow to feed.  These plants may be completely removed or may begin to wilt and die with little sign of injury above ground. It is important to know that cutworm larvae are primarily nocturnal and will hide under debris or in the soil during the day to escape sunlight, so finding larvae in the daytime is rare or hard to do.

4. Damping Off: The single term used to describe underground, soil line, or crown rots of seedlings due to unknown causes is damping-off. The term actually covers several soil borne diseases of plants and seed borne fungi. 

5. Bean Leaf Beetle:   Early planted soybeans and especially the first fields to emerge in an area may exhibit seedling injury due to feeding by overwintering adult Bean Leaf Beetle populations. Foliar injury due to adult BLB feeding will again appear in late June and continue until fall as a succession of 1st and 2nd generation Bean Leaf Beetle adults emerge and feed on the crop

Click here to see pictures of the insects listed above.

If you have questions, contact your local Hoegemeyer District Sales Manager or Agronomist.