By Mike Stanyard, NWNY Dairy, Livestock & Field Crops Team – Field Crops Specialist and Team Leader
It has always been encouraged to spray the earliest planted fields for winter annual weeds (purple deadnettle, chickweed, chamomile) in late fall. However, there are so many other things going on in the fall and your windows of opportunity for spraying can be slim to none. You never know what the weather will be like in the spring and timely weed control can be tricky. Here is an update on broadleaf and grass control products for this spring with two new products just registered in 2018.
Broadleaf Weeds. Harmony Extra and Harmony SC are still the backbone of many spray programs. Harmony Extra (Harmony + Express), controls a wider range of broadleaves and it is favored over other products because of its control of corn chamomile, wild garlic and chickweed. A recent point of concern has been the number of marestail/horseweed plants that are making it through until harvest. This may be an indication that you have an ALS resistant marestail population. Both of these products can be applied up until the flag leaf is visible (before Feeke’s stage 8).
Growth regulator products like Clarity, Banvel, MCPA and 2,4,-D are effective against many broadleaves and should take care of ALS resistant marestail. They are usually tankmixed with Harmony products for extra control of winter annuals and perennials. Application past Feek’s stage 6 (jointing) is not advised as it could lead to plant injury and yield reductions. Unfortunately, I have seen annual marestail emerge after this stage.
Huskie (Bayer Crop Science) just received a 24(c) Special Local Needs label for New York on March 2nd. It is a combination of pyrasulfotole (an active not labeled in NY yet) and two formulations of bromoxynil (ie Buctril). The SLN labeling is for marestail/horseweed control in wheat, barley, rye and triticale. Huskie can be used for control of marestail in winter malt barley as well. Talking with Dwight Lingenfelter, Penn State weed scientist, Huskie would be best tank-mixed with Harmony Extra for complete broadleaf control. In fallow ground trials over the past two seasons, Penn State has been seeing (90-95%) control of 8 inch marestail with Huskie at the highest rate. Huskie can be applied up until flag leaf emergence.
Grasses. NYS has a 24(c) Special Local Needs label for Osprey for control of roughstalk bluegrass and cheat in winter wheat. It expires at the end of 2018. Osprey can be applied in the fall and spring but must be applied early in the spring, prior to the jointing stage in winter wheat.
Prowl H2O can be applied to wheat and triticale in the fall and the spring but must be applied before weed seeds germinate. It is very effective on our annual grass spectrum and some of our annual broadleaves but must be applied early in the spring prior to weed emergence.
Axial XL (Syngenta) was just registered on January 12 in NYS and is labeled for the control of grasses in wheat and barley. The active ingredient is pinoxaden which is in Group 1 (ACCase mode of action). Axial can be applied to wheat and barley from the 2-leaf stage to pre-boot stage. It is labeled for Foxtail (giant, green and yellow), volunteer and wild oats, annual ryegrass, barnyardgrass and canarygrass. Axial XL can be used for annual grass control (foxtails most importantly) in spring malt barley. For optimal control, it is recommended to apply when grasses have between 1 and 5 leaves on the main stem or prior to emergence of the 3rd tiller. THIS PRODUCT IS NOT LABELED FOR OATS!!!
We are still advising growers not to mix your herbicide and nitrogen applications and spray separately. The leaf burning can cost us up to 10 bushels and could get worse as temperature and humidity increase.