Fall is a key time for controlling diseases and weeds that can cause long lasting problems on turfgrass. Bayer has a range of solutions with StressGard Formulation Technology for controlling fall diseases on cool and warm season turf such as dollar spot, take-all patch, leaf spot and large patch. Fall control of annual bluegrass and winter broadleaf weeds can be done efficiently and effectively with pre-emergent herbicide applications. Specticle Flo, a new herbicide, can be a solution for these problems. Timing for the control of these pests is the most important and being aware of the critical temperatures or dates for these will greatly aid in easily managing them.

Although almost everyone can agree that the summers in the Mid-Atlantic can be brutal for turf management, the fall is a critical period for disease and weed control that can help make life easier going into the next year. Diseases of both cool and warm season turf can still be active causing problems in the fall through winter and the fall is an important time for stopping annual bluegrass invasions, especially into warm season turfgrass.

Fall Diseases of Cool Season Turf
Dollar spot is undoubtedly the most important disease of creeping bentgrass in the Mid-Atlantic, and can have three distinct periods of activity: spring, summer and fall. It's often most active when daytime temperatures are between 70-90°F but as long as temperatures remain above 60°F, the door is open for dollar spot to develop. Although it is traditionally thought of as a summer, hot temperature disease, in recent years fall epidemics have become more troublesome and intense in severity. Part of the reason is that extended hot weather with daytime temperatures above 90-95°F can shut down the dollar spot fungus in the summer and the intense fungicide programs used at that time can often keep turf ahead of the disease. But fall conditions, with moderate temperatures and increased moisture, coupled with reduced day lengths that result in less turfgrass vigor, can bring back a resurgence of dollar spot.

To complicate matters, by the fall, many populations of dollar spot have been exposed to multiple fungicide applications and in some cases, the frequency of fungicide resistance, especially to the DMIs, can be quite high at this time, making control of them problematic.

Bayer Solutions for fall dollar spot outbreaks include Tartan and Interface, with StressGard Formulation Technology to help control disease and improve plant health in fall conditions. Tartan has triadimefon which is a very dollar spot active DMI plus trifloxystrobin that can help provide dollar spot control and pick up a broad spectrum of diseases like leaf spots, brown patch and gray leaf spot that may develop in the fall. Interface, being a non-DMI fungicide, can help take care of DMI-resistant dollar spot and provide control of brown patch, leaf spots and even some early snow mold or Microdochium patch that develops.

Take-all Patch is often considered a spring and summer disease of creeping bentgrass but the most effective prevention actually starts in the fall. Take-all actually starts infecting roots as soil temperatures drop into the 50-65°F range, and then again in the spring as soil temperatures warm up into the same range. Often it's not until you have summer stress that you see the damage when plants with rotted root systems are unable to function and die off in heat or drought conditions.

The best plan of action for take-all patch (along with improving soil conditions and providing adequate manganese levels) is to focus on fall fungicide applications. Start with an application when soil temperatures dip down past 65°F and then 28 days later to provide enough material to control the fungus. Since the disease is in the soil and root zone, fungicides should be watered in to the root zone for best effect. A third application may be needed in the spring in the 50-55°F soil temperature range if take-all patch has been a chronic, severe issue.

Chipco Triton FLO is a great choice for fall and spring applications. As a systemic DMI fungicide, it can penetrate into the roots to get to where the fungus is attacking. With its StressGard Formulation Technology, it has less PGR effects than many other DMI fungicides, helping to make sure that you're not adding any stress to the situation when trying to control take-all.

Fall Diseases of Warm Season Turf
Bipolaris leaf spot can be a very problematic cool weather stress disease of warm season turf. With the increase in bermudagrass putting greens in the southern Mid-Atlantic, leaf spot has become more of a problem in the region. Leaf spot is most active when bermudagrass growth slows down and it's most common when daytime temperatures are between 55 to 85°F with wet or cloudy conditions.

Interface is an ideal fungicide to use in a leaf spot control program. The combination of iprodione and trifloxystrobin have excellent activity versus leaf spot fungi and the StressGard Formulation Technology helps reduce down plant stress that opens the door for this disease to occur. Since leaf spot has a good risk of fungicide resistance development, rotating Interface with contact fungicides is a good idea. Tank mixes of contacts with Chipco Signature can be especially helpful to increase plant health and reduce susceptibility to the disease.

Large patch is caused by Rhizoctonia solani and most destructive on zoysia grasses, but can also affect bermudagrass. The disease is most common on poorly drained soils like heavy clays on fairways or even landscapes. The disease typically starts in the fall as soil temperatures drop into the 70-75°F range, and the fungus attacks warm season turf that is slowing down and starting to go dormant, and then reactivates in the spring as the turf is coming out of dormancy. Fall infections are the most important to control as they can cause damage that can't be recovered from until next summer when warm season turf is actively growing again.

Bayer solutions include preventive fungicide applications using Chipco Triton FLO or ProStar WG. Bayer has guaranteed programs for large patch control using both fungicides when used in a program approach.

Fall Weed Control
Annual bluegrass Poa annua is well adapted to cool fall conditions and preventing its establishment in the fall is a key to stopping its spread. On dormant bermudagrass, winter clumps of annual bluegrass can be unsightly and provide negative competition for bermudagrass growth in the spring and summer. Control of annual bluegrass with pre-emergent herbicides in the fall can be one of the most cost effective ways to manage this weed.

A Bayer solution for annual bluegrass in bermudagrass is Specticle Flo, a new pre-emergent herbicide that can be used at low rates with long lasting residual control. It can be used on golf courses, sports turf and landscape turf to control annual bluegrass and many winter broadleaves like henbit, bittercress and chickweed. There a number of annual bluegrass and weed control programs that can be used in the Mid-Atlantic that guarantee up to 8 months of weed control all the way through March or April of 2014 as detailed here: http://bit.ly/172ItIo

Specticle Flo can only be used on warm season turfgrass and should never be applied to cool season turfgrass. See the Specticle Flo label and technical sheets for more information on how to use this product.

For post-emergent control of poa annua, Revolver is a great option. Revolver also provides control of other cool season grassy weeds, such as tall fescue clumps, and perennial ryegrass clumps.

Summary
Fall is a great time in the Mid-Atlantic for cooler weather, family fun like Halloween and all kinds of football, but it's also a time to stay on top of key pests for turfgrass. Bayer provides a number of solutions for tough diseases and weed problems. More information on Bayer solutions can be found at the Backed by Bayer webpage www.backedbybayer.com