Dry Weather and Fall Herbicide Options

OSU’s Dr. Mark Loux provided an overview of dealing with fall herbicide applications during dry conditions in the most recent CORN Newsletter. I have summarized a few basic points below:

  • don’t be in a rush to apply. There is really no risk of less effective control by delaying treatment, even through mid to late November
  • herbicides are more effective on dandelion after a frost in late October or November
  • waiting until early November could also allow for a more informed decision on whether fall treatment is actually necessary

This same thinking can be applied to winter weed management in no-till wheat:

  • postemergence herbicides applied in November,  such as dicamba plus Express (or the equivalent generic product), can be an effective option
  • cautionary note: labels for many wheat herbicides specify that they should not be applied in the fall until wheat has 2 to 3 leaves, which does allow substantial time for growth of weeds that have already emerged

Full podcast available here:


September 28, 2010 at 5:51 pm

Fall is a Great Time to Fertilize Lawns

The September issue of Purdue’s Turf Tips (http://www.agry.purdue.edu/turf/tips/2010/09102010_fertilizer.html) has a few simple and straightforward recommendations for lawn care:

The amount of nitrogen fertilizer required by turf depends on various management and environmental/management factors. A good rule to follow is to never apply more than 1.0 lb N/1000 sq. ft.  in any one application.

So the question remains, what type of fertilizer to use? There are many different brand names, marketing tools, as well as different analyses of fertilizer.  All these factors can make the decision on which fertilizer to use seem a bit confusing. Purdue offers the following advice:

There are many fertilizer choices available to the professional and the homeowner. Organic, inorganic, and synthetic organic products are all available. As with all plants, turfgrasses cannot tell the difference between the sources of nutrients. Some products contain high amounts of slow-release N while others contain none. Our recommendation is to use a mixture of quick and slow-release nitrogen sources in most situations. Although there are exceptions to the rule, it is good practice to use products with a greater percentage of slow-release nitrogen sources during warmer months and a greater percentage of quick-release nitrogen sources during cooler times of the year. Your soil test report will help you to choose which fertilizer might work best for your lawn.

Full podcast here:  


September 20, 2010 at 11:53 am

Strategies to Control Marestail

This is easily one of the worst marestail years I have seen. Marestail is a weed that can follow a winter or summer annual life cycle. Marestail plants start out as a rosette, generally bolt in April/May, flower in July, and set and disperse seed from August to October. Each plant can produce up to 200,000 seeds that travel via the wind.

For those of us who deal with marestail, we know that post-emergence control of many marestail populations is close to impossible. As such, the goal of a marestail management program is to ensure that the combination of fall and spring burndown and residual herbicides results in a weed-free seedbed at the time of soybean emergence, and little to no emergence of marestail between soybean emergence and crop canopy closure. But keep in mind that even the most effective marestail management programs can fail to completely achieve this, but they often keep the populations low enough in the soybeans that they are not problematic.

For marestail control suggestions, OSU Extension Weed Specialist Dr. Mark Loux suggests the following as one possible approach:

Apply a combination of glyphosate and 2,4-D in the fall, followed by application of residual herbicide in the spring prior to soybean emergence. At the time of soybean planting, the field is likely to be infested with marestail that emerged earlier in spring, so include effective burndown herbicides to control emerged plants. Keep in mind these plants can be very small and not noticeable.

The idea here is to apply an herbicide treatment in the fall that adequately controls emerged marestail, but does not break the bank and allows use of residual herbicide in the spring. Canopy herbicide can also be used in the fall, but use of metribuzin in the fall preserves the option to plant corn the following spring. Follow the OSU Extension CORN newsletter for the latest updates at corn.osu.edu


September 7, 2010 at 3:04 pm 1 comment

How Soybean Sudden Death Syndrome Looks at the Root

Most agronomists and farmers are good at identifying soybean Sudden Death Syndrome (SDS) through leaf symptoms (below image courtesy of Glen Arnold, OSU Extension Putnam County):

Click image for full view

.

However, there is another diagnostic feature that can be used as well.  OSU’s Anne Dorrance will also use blue spores of the SDS fungus on a soybean tap root as a diagnostic feature.  This avoids incorrect diagnosis, that is, diagnosing brown stem rot or interveinal chlorosis from nutrient deficiency as SDS.

Click image for full view

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Full podcast here:  


August 24, 2010 at 12:07 pm 1 comment

Controlling Troublesome Crabgrass in Turf

The follwing is a repost from the 8/5/10 OSU Extension BYGL Newsletter

Crabgrass is flourishing in some lawns this year, and in some cases these are lawns that have been ‘crabgrass free’ for several years. What’s happening? According to Dave Gardner (Turfgrass Science, OSU Department of Horticulture and Crop Science) the answer can be summed up in three words: hot, wet, and humid. The 2010 growing season has been unusually hot and humid with many areas experiencing successive days above 90F. And until recently, much of Ohio has had consistent rainfall events keeping soils wet.

It is hard to mistake crabgrass. Crabgrass has spreading stems and wide, flat leaf blades that lie on the ground. The spike-like seed heads are arranged like fingers which is described by the name of the genus, Digitaria. Crabgrass is an annual plant, which means that once seed is produced, the plants die. This life cycle presents a serious problem for lawns that are dominated by crabgrass; the lawns become dominated by dead crabgrass plants in the fall. Of course, this also presents an opportunity since the best time to seed turfgrass is in late summer to early fall. The new turfgrass plants will rise just as the crabgrass declines.

Crabgrass is a “warm-season” plant meaning that conditions have been ideal for their growth and development. Most grasses used in Ohio lawns are cool-season plants, meaning that high temperatures stunt their growth; consequently, they are at a disadvantage when competing head-to-head with warm-season plants. This is particularly a problem in lawns with thinning stands of turfgrass. Short-term control of nutsedge and crabgrass usually focuses on herbicide applications. Long-term control focuses on growing dense stands, utilizing high populations of turfgrass to maximize competition with these weeds.

A herbicide application targeting crabgrass may be combined with a turfgrass “rejuvenation” program, as long as care is taken to observe the waiting period between the time of the application and the time of seeding. For example, quinclorac (e.g. Drive) may be used effectively as a postemergent selective herbicide for late-season crabgrass control. The targeted crabgrass must have 6 or more tillers; it will not control crabgrass that has just started to tiller. Seeding of Kentucky bluegrass may be done 28 days after a quinclorac application, and seeding of turf-type tall fescue or perennial ryegrass may be done 14 days after an application.

Full podcast available here:


August 11, 2010 at 8:15 am

Insect Damage to Soybeans? Nah… It’s Wind Damage.

Winds in excess of 40 mph on August 4 left a few soybean leaves in tatters. A few who walked into their soybeans the next morning immediately thought ‘insect damage’.

Overview image showing torn, tattered soybean leaves in the upper trifoliates.

Another view showing torn, tattered soybean leaves.

Here's a closeup shot. Notice the irregular shape of leaf damage.

An indication that this isn't insect damage is that insect damage would not be so 'jagged'.

Final clue that this isn't insect damage. Wind damaged pieces of torn soybean leaf on the soil under soybean plants.

More torn soybean leaf pieces on the ground.

Nah, not insect damage. This was a clear-cut case of wind damage to soybeans (soybean stage R2).

August 6, 2010 at 8:15 am

Who Pays for Dead and Dying Ash Tree Removal?

The below article is a repost from the July 29, 2010 OSU BYGL Newsletter available at: m http://bygl.osu.edu/index.php?option=com_content&view=article&id=904:bygl-july-29-2010&catid=1:latest-news&Itemid=74

As more and more ash (Fraxinus spp.) trees succumb to the EMERALD ASH BORER (EAB), some tree owners are asking who will pay for the removal of these infested trees.

In 2002, the EAB was first discovered in Michigan, and then in 2003 it was first found in Ohio. Early on in the program, there were eradication efforts in place. Ash trees were identified, marked, removed and chipped, as part of the eradication efforts and was done at no cost to the property owners. The goal was to eliminate the insect, thus saving ash trees outside of the core of the infestation. Additional finds keep popping up in several states, and eradication efforts were halted as the insect was more wide spread than anticipated.

With this change in the program came some options for individuals managing ash trees. Chemical treatments to protect trees became a tool for those wanting to “save” their tree(s) from EAB, but with that also came the responsibility to deal with dead and dying ash trees, especially those with adherent risk to people and property if they were to fall. Since that time, communities, businesses, woodland owners, and homeowners are responsible for the management of their own ash trees, which includes the removal costs; costs that can often range from several hundred to several thousands of dollars.

Wood utilization is an opportunity that some may have not thought much about before EAB. Ash trees from infested areas have been transformed into beautiful furniture; carved into walking sticks, bowls and other pieces; sculpted by chainsaw artist into unique pieces; used for railroad ties, mulch, firewood, and more. Michigan has led the way in the ash wood utilization, and Ohio is hoping to learn some valuable lessons. Check out some of the great work folks working with the Southeastern Michigan RC&D at http://semircd.org/ash/

Podcast:  


August 5, 2010 at 9:41 am 4 comments

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This blog is no longer being maintained. Information on this blog may still be relevant, but for the latest agronomic information and farm management information please visit http://corn.osu.edu and http://ohioagmanager.osu.edu, respectively.

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