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Channel Field Check Up
KAYLISSA HALTER
ROBINSON, ILL.
“Start clean, stay clean” is our motto in Southern Illinois to fight unruly weeds and 2016 should be no exception. We all remember the monsoon we faced in 2015 that caused many herbicide applications to be short-lived or not get applied at all, which resulted in a lot of weed escapes. In our case, those escapes turned into a sea of waterhemp plants that produced seed heads and replenished our seed bank. Growers should anticipate the potential of heavier weed pressure than normal and have a weed management plan of attack. When creating a weed-management plan for your farm’s situation, you should consider:
Importance of early weed control. Crops are most vulnerable to weed competition at planting and as the new plants emerge. Significant yield is at risk if weeds are allowed to compete with crops during the first several weeks after planting. If not controlled, they can also decrease harvest efficiency and produce seed, which can impact future crops. The timing and intensity of weed emergence determines which species will be the most competitive with the crop, as not all weed species compete equally.
Timing. Ideally, weeds should be controlled at least a couple of weeks prior to planting, to allow for decomposition of the plant material. Planting into existing weeds, or heavy weed residue that has not had time to decay, can interfere with seed placement and reduce emergence due to poor seed-to-soil contact. If the burndown is delayed, planters should be adjusted to compensate for the increased crop residue.
Burndown applications. Starting with clean fields at planting is an essential step for proper weed management. Preplant burndown tank mixtures remove early weed infestations and provide broad spectrum foliar and residual weed control. A burndown plus residual herbicide tank mix, or tillage, may be required to remove early weed infestations. Residual herbicides applied with burndown several weeks prior to planting may encounter environmental conditions that limit residual activity into the growing season. An earlier than normal post herbicide application may be required to limit weed competition. The early post application requires a residual component to control late emerging weeds that impact yield potential. You should always check individual product labels for precise instructions.
Environmental factors. Environmental conditions affect the rate of weed growth, crop development, crop tolerance to herbicides, and herbicide performance. Fluctuating day and night temperatures are typical in the spring. The efficacy of a burndown herbicide application can be reduced by cold temperatures. It is recommended to wait on applying herbicides until nighttime temperatures are above 40°F and daytime temperatures are in the high 50’s to low 60’s. Weed control may be even more effective if there are several days of warmer weather prior to herbicide applications rather than applying on the first warm day of the season.
http://www.channel.com/agronomics/Pages/Considerations-for-Burndown-and-Early-Season-Weed-Management.aspx
Tank mixtures: The applicable labeling for each product must be in the possession of the user at the time of application. Follow applicable use instructions, including application rates, precautions and restrictions of each product used in the tank mixture. Monsanto has not tested all tank mix product formulations for compatibility or performance other than specifically listed by brand name. Always predetermine the compatibility of tank mixtures by mixing small proportional quantities in advance. ∆
KAYLISSA HALTER: Channel Agronomist
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