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Questions of the Week!!!

Below are various questions I received this week. They include forage moisture, weed control in corn and cotton, and Aspergillus crown rot. Also during the last couple of weeks we planted a few on farm corn demonstrations.

What should my forage moisture be for baled silage?

Considering all factors, the optimum whole-plant moisture for baled silage is 50-60%. Baling at the proper moisture content is a key to success in producing baleage. Forage containing less than 40% or more than 65% moisture should not be baled for silage in order to avoid excessive molding or spoilage. Producing bales with too much moisture reduces forage quality and increases the chance of undesirable butyric acid fermentation. Baling with low moisture reduces fermentation and increases mold production, which greatly increases storage losses.

How do I determine forage moisture?

I have received a question or two about how to determine forage moisture this week.  Growers need to make sure they are baling forages at the proper moisture depending on storage method.   The most accurate method of determining moisture is by using a microwave.  The microwave method of determining forage moisture can be found HERE. 

Also, Dr. Lisa Baxter, UGA Forage Specialist, has a great job discussing various methods of moisture determination in forages. This YouTube video can be seen HERE.

What are the plant-back intervals for Valor and Direx in my cotton burndown?

Cotton growers have been applying burndown treatments this week before the rain. It is essential to start clean at planting and residual herbicides are very critical to help growers keep Palmer amaranth from emerging. The table below illustrates the plant back intervals for Valor or Direx applied at burndown. 

HerbicideTime Interval Before PlantingSpecial Comments
  ValorIn strip-till, where the strip-till rig (including ripper shank) is run after application and before planting.
1) > 30% ground cover = 7 days
2) 10-30% ground cover = 14 days plus 0.5” rain/irrigation
3) <10% ground cover = 21 days plus 1.0” rain/irrigation.

In no-tillage production or when the strip is implemented prior to application.
Valor plant-back interval should be 28 days. Additionally, 0.5” (>10% ground cover) or 1” (<10% ground cover) rainfall/irrigation is needed.
Do not exceed 2 oz/A if planting within 30 days.

If applying Reflex (or generic PRE), add an additional 7 days to no-till planting intervals.
  Direxno till: 10 d
strip till after application and before planting: 0 d
Do not exceed 1 qt/A, see label for rate on your soil. 
Source: 2021 UGA Cotton Production Guide

How do I manage Aspergillus crown rot in my peanuts?

According to Bob Kemeriat, UGA Plant Pathologist, Aspergillus crown rot is an important seedling disease, especially when conditions are hot and dry at planting, or when seed quality is a concern.  Farmer-saved seed is often at the greatest risk.  Let’s discuss some ways to manage this disease. 

  1. Ensure quality of seed.
  2. Ensure effective fungicide seed treatment with excellent seed coverage. 
  3. In 2021, Rancona will likely be the predominant fungicide seed treatment for peanuts.
  4. Use in-furrow products such as Velum and Proline.  Note that azoxystrobin products have been widely used as in-furrow treatments in peanuts, but are less effective against Aspergillus crown rot now than in the past. 
  5. Manage insect such as Lesser Cornstalk Borers.
  6. Avoid planting into hot and dry soils.
  7. Irrigate to cool hot soils. 

What herbicide options do I have to terminate my first corn stand so I can replant?

Growers sometimes get into a situation when they have to replant sub optimum corn stands. So I asked Dr. Eric Prostko, UGA Weed Specialist, about herbicide options for controlling an existing stand of RR corn in order to replant…

Below are slides from Dr. Prostko illustrating various treatments. Volunteer corn control with Gramoxone + Atrazine or Liberty was incomplete and these plots still made some yield (27-28 Bu/A).  Select Max  will result in complete control but it does take about 14 days to get to 100%. According to the UGA Pest Management Handbook, growers need to wait 6 days before re-planting corn when using the 6 oz/A rate of Select Max or 3 oz/A of a 2 lb product. Tillage is also an option for a replant situation. If you have questions about this subject please contact your local county Extension agent.

Annual Morningglory Control in Field Corn
One of the most troublesome weeds to control in field corn is annual morningglory. In Georgia,
morningglories are particularly difficult to manage due to the fact that residual herbicides do not provide
full-season control and corn maturation in late June/July allows ample sunlight to reach the soil surface
which stimulates late-season emergence/growth. In heavy infestations, complete control of
morningglory is almost impossible in our environment. A few things to consider:

1) Use a PRE (1 qt/A) and POST (1.5 qt/A) application of atrazine (4 lb ai/gal). The second application
of atrazine must be applied before the corn exceeds 12” in height. POST applications can be delayed
until that time to extend residual control.
2) Consider using the Liberty-Link (LL) system. Generally, Liberty is more effective on morningglory
than glyphosate. Atrazine can be tank-mixed with Liberty for residual control.
3) Other herbicides that can be tank-mixed with glyphosate to improve the control of morningglory
include, 2,4-D, dicamba, Status, Aim, and ET.
4) Consider using a LAY-BY or PDIR application of Evik.
5) Consider using a harvest-aid such as Aim. Late-season applications of Aim will not completely
remove morningglory plants from a field but will desiccate the vines enough to improve harvest.
Aim has no effect on smallflower morningglory.
6) Harvest corn early before morningglory plants take over the field. Obviously, this management
tactic will necessitate the use of on-farm drying/storage facilities.

Volunteer Peanut Control in Field Corn
Volunteer peanut plants can be one of the most difficult weeds to control in field corn. Peanut plants are
sensitive to POST applications of glufosinate (Liberty), split applications of glyphosate (Roundup), or
dicamba (Clarity, Engenia, Fexapan, Status, Xtendimax). Lay-By/PDIR applications of ametryn (Evik)
may also provide some control

2021 Colquitt County Corn Demonstrations…

We also planted several on farm demonstrations evaluating corn varieties, in furrow fungicides, and various seed rates.

.If you have any questions please contact the Colquitt County Extension office…

Have a good weekend

Jeremy M. Kichler

Colquitt County Extension Coordinator

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