Thursday, September 14, 2017

What's Your Fall Herbicide Program?

With harvest coming to an end, it is time for growers to begin prepping for the next year by applying fall herbicide to their fields.  Fall herbicide applications are often made on no-till fields targeting winter annual species such as marestail (horseweed), purple deadnettle, henbit, and chickweed.  Applying a herbicide in the fall can help control these weeds prior to them reaching the reproductive stage and will allow for a cleaner field prior to planting next year’s crop.

Did you know?
Purple deadnettle (top) and henbit (bottom) are both alternative hosts of soybean cyst nematode (SCN).  If these weeds are not controlled in the fall, SCN levels can continue to increase rapidly and infect the following soybean crop.

University of Kentucky, College of Agriculture, Food & Environment

Application timing
In the Burrus footprint, the application timing is likely between early October and Thanksgiving.  Since the target of the fall herbicide application is the emerged winter annual species, it is important to allow the weeds time to germinate and emerge through the crop residue.  Applying the herbicide too late can cause issues with poor herbicide efficacy due to reduced activity within the plant. 

Fall programs typically include dicamba and/or 2,4-D plus glyphosate to control weeds that are currently emerged.  To get residual control of emerging winter annual species, residuals can be applied as well.  The chart below shows recommended herbicide programs based on next year’s crop.  It is important to not rely on the residual to provide control of spring emerging weeds.  Most university research shows that a soil residual herbicide in the fall will deteriorate and not control the summer annual weeds (i.e. waterhemp) in the spring. 
Any crop next spring
Glyphosate + 2,4-D
Autumn™ Super + glyphosate or 2,4-D
Metribuzin + 2,4-D (excluding dandelions)
Authority® MTZ + 2,4-D (excluding dandelions)
Basis®/Harrow™ + 2,4-D
Dicamba + 2,4-D
Express® + 2,4-D
Soybeans next spring
Canopy® EX/Cloak® EX/Fallout™ + 2,4-D
Canopy®/Cloak® DF + 2,4-D (excluding chickweed)
Corn next spring
Simazine + 2,4-D

Adapted from 2017 Weed Control Guide Ohio, Indiana and Illinois

As always, follow the herbicide label when making a herbicide application.  For more information regarding fall herbicide programs for your farm, contact your Burrus agronomist. 

By Jamie Long, Burrus Sales Agronomist

Friday, September 8, 2017

What is a Tassel Ear?

This year, many asked about tassel ears, which is when corn plants form an ear (female flowers), instead of the tassel (male flowers).  Normally, the female parts of the tassel and the male parts of the ear shoots abort, on a corn plant,which results in unisexual flowers (ear and tassel). However, every once in a while, the development of the tassel is altered and the female parts result in the development of kernels.  This results in the tassel and ear on the same structure on top of a corn plant.  The physiological factors for the development of female flowers on the tassel is thought to be hormonally-driven, but the environmental trigger that alters the hormonal balance is not exactly known.  

Tassel ear

Some hybrids could be more likely to form a tassel ear.  Tassel ears can be on tillers or suckers. These tassel ears can form when the growing point is damaged by hail, wind (green snap), animal feeding, frost, flooding, herbicides, and mechanical injury before V6.  For example, we see many tassel ears near plot alley ways  that were cut earlier in the season.  Tillers or suckers are more likely to be found in low plant densities.  Tassel ears can also be found on field edges where early season soil compaction and saturated soil conditions could be the reason for this abnormality.

This year's early season wet weather could be the reason we could be finding more tassel ears, but do not to confuse tassel ear with the disease, crazy top, where infection causes tassel or shoot development to be an abnormal mass of leaf tissue.

Tassel ear found in a drowned out spot in a field