Conservation tillage, a vital observe in farming for a carbon market, calls for a special strategy to weed control.
“Weed management in conservation tillage systems puts an increased burden on chemical control,” says Josh McGinty, Texas AgriLife Extension agronomist, Corpus Christi.
McGinty mentioned the challenges farmers face with weed administration, particularly herbicide resistant weeds, throughout a “Carbon Farming in Texas” workshop, held in-person and on-line not too long ago in Robstown.
The finer factors
McGinty mentioned no-till manufacturing places “a greater emphasis on the ‘finer points’ of weed control.” These factors embrace:
- Scout and establish drawback weed species, together with herbicide resistant species.
- Overlap residual herbicides from preplant by early- to mid-season.
- Apply postemergence herbicides on the proper time and to the best dimension weed.
- Handle weeds in area margins and roadsides.
- Rotating crops and expertise are extra essential than earlier than.
McGinty additionally mentioned cowl crops could be helpful in weed control. “But it’s a balancing act with moisture, providing enough for the cover without robbing the cash crop.”
A strip-tilled area on the Corpus Christi Texas A&M AgriLife Analysis Middle the place Valor is used to maintain it clear over the winter. (Picture by Josh McGinty.)
He mentioned producers must be able to go early within the season. Figuring out key drawback weeds is crucial. He cited pigweed, frequent waterhemp and careless weed as resistance challenges.
“Pigweed and waterhemp are prolific seed producers,” McGinty mentioned. “One female plant can producer 200,000 or more seed and may exceed one million under favorable conditions.”
He mentioned these weeds have proven resistance to atrazine, glyphosate, and ALS herbicides in South Texas.
He mentioned pre-plant included/preemergence herbicides are vital in managing these weeds. In cotton, he recommends a preplant/pre-plant included utility with yellow herbicides. He would add a preemergence utility of Cotoran/Caparol plus a bunch 15 product. In sorghum, he recommends atrazine plus a bunch 15 herbicide. “We may have mesotrione as an option in the near future.”
McGinty recommends a postemergence utility of glufosinate/2,4-D/dicamba for cotton. For sorghum, he recommends atrazine plus Huskie/Starane NXT.
Different drawback weeds
False ragweed, a difficult warm-season annual, germinates from 48 to 97 levels Fahrenheit and produces 15,000 to twenty,000 seed. “False ragweed is resistant to glyphosate, atrazine and paraquat, as documented in South Texas,” McGinty mentioned.
Control ought to begin with a pre-plant burndown. “Sharpen is an easy option in grain,” he mentioned. “Glufosinate is good for cotton.”
Pre-plant included and preemergence herbicides for false ragweed control in cotton embrace a preemergence choice with Cotoran/Caparol plus a bunch 15 product. For grain, he recommends atrazine plus a bunch 15 and maybe mesotrione quickly.
Postemergence recommends embrace:
- Cotton, “primarily glufosinate. Auxins are only effective on very small seedlings.”
- Corn, glufosinate.
- Sorghum, atrazine plus Huskie/Starane NXT.
Texas panicum is a tough-to-manage, heat season grass, “McGinty mentioned. “It’s more durable to control than different annual panicums.
“Control is no problem in cotton and corn,” McGinty mentioned. “We have plenty of options. It’s different for grain sorghum, and we need to consider managing Texas panicum with rotation or herbicide tolerant grain sorghum hybrids.”
He supplied a number of choices together with Inzen from Corteva. “Inzen provides very good control of small Texas panicum, postemergence with Zest,” he mentioned. Inzen affords no soil exercise.
Igrowth, from Advanta is imidazolinone tolerant. “It provides good control of small Texas panicum, postemergence with Imiflex. Preemergence control of panicum is similar to a group 15,” he mentioned.
Double Staff, from S&W is ACC-ase tolerant, with “excellent grass control, postemergence with First Act.” Double Staff has no soil exercise.
McGinty mentioned Pennsylvania pellitory, a cool-season annual, could change into “a major issue after a few years of no-till or strip-till management. It will mature at cotton or grain planting time and is difficult to control with any herbicide. Evaluation of herbicides is underway.”
McGinty mentioned area residue can have an effect on herbicide exercise, however the South Texas local weather usually “burns up residue quickly. We see adequate reason to treat and prevent weed emergence,” he mentioned.
He additionally cautioned producers about weed escapes. “Some applications will burn the top of the weeds but will not get the lower canopy.” These escapes usually survive and produce seed that add to the weed seed financial institution in coming years.
He mentioned most weed peak for Liberty to be efficient is 3 to 4 inches. “We see a significant difference in control on 4-inch weeds compared to 8-inches or 16-inches.”
McGinty mentioned controlling weeds in conservation tillage methods comes with new challenges however is feasible. “Timing is critical,” he mentioned.
To view the workshop in its entirety, go to https://youtu.be/dWX5usx7LoE.