I am constantly searching for articles that contain information that may benefit crop producers in the Midsouth, and then recommending that producers read those articles that I think have information they can use in their operations. My hope is that this will put additional producers in contact with what I consider to be valuable information that will help them in the coming growing season.
In this case, I am providing links to two articles by Emily Unglesbee, DTN Staff Reporter. I believe that the information contained in these articles is of value to Midsouth soybean producers, and that they should be aware of the helpful content contained therein.
The first article titled “Navigating Nutrient Products (Dec. 9, 2021)” contains information that producers can use to determine if a touted new fertilizer or biological soil additive is actually needed or will do the intended job if used. The following questions should be asked and answered to help with this decision.
• WHAT DOES THE PRODUCT DO? Identify the active ingredient(s) and what it/they are supposed to do, and look for third-party data from replicated trials that support the manufacturer’s claim that in fact the product will produce measurable economical effects.
• DO I NEED THAT ON MY FARM? A soil test is the best way to determine if soil at a production site will actually benefit from application of a product that has an ingredient that is touted to address a specific soil problem.
• WHAT IS YOUR MEASURABLE GOAL? Is there a specific goal such as increased nutrient-use efficiency with concurrent less fertilizer applied that will maintain or even increase yields? Don’t look at these products as a replacement for a portion of a fertility program or as a quick fix for problem fields, but rather as a means to improve production on an otherwise properly managed production site. Will a chosen product potentially do this?
• HOW ARE YOU GOING TO MEASURE IT? Start small with any chosen product (don’t go all-in at first use), use production data from multiple years to account for the vagaries of weather and to measure possible cumulative effects, and leave check strips in every field or area where a product is applied.
• HOW WILL THE MYRIAD PRODUCTS WORK TOGETHER? Will there be positive synergies among the myriad products that may be applied together? A “yes” answer to this question could provide additional impetus for the use of specific soil additives.
• Bottom Line: More and more soil additive products are coming into the market. This means that producers will have to become/stay vigilant about their true worth and effectiveness, and depend on trusted private and public researchers to provide the data that will verify their economic contribution to crop production enterprises.
Producers are encouraged to read the above-linked article and “digest” its information before making a final decision about using soil additives that are touted to accomplish certain goals.
Click here for an article on this website that discusses using biological pesticides applied to the soil as part of an IPM strategy.
The second article titled “Nothing Simple With Herbicide Resistance–The New Resistance (Dec. 31, 2021)” contains information about herbicide-resistance development in weeds provided by Dr. Larry Steckel, Univ. of Tenn. Weed Scientist, Dr. Aaron Hager, Univ. of Ill. Weed Scientist, and Dr. Pat Tranel, Univ. of Ill. Molecular Weed Biologist. Pertinent points from the article follow.
• Separate populations of dicamba-resistant waterhemp have been confirmed in Tennessee and Illinois.
• In Tennessee, the resistant populations were determined to be a classic case of the weed evolving resistance as a result of long-term heavy use of dicamba. In Illinois, the resistant population was deduced to involve a new mechanism known as metabolic resistance, which lets a weed species escape damage from a herbicide by its rapid metabolism of the herbicide chemical.
• Metabolic resistance allows a weed species to survive the application of multiple classes of herbicides, even those that it has not been exposed to. Thus, mixing multiple modes-of-action herbicides, which is a cornerstone of managing herbicide-resistance development in weeds, will not prevent the development of metabolic resistance.
• The identification/development of metabolic resistance in weeds further underlines the need for non-chemical weed control measures such as harvest weed seed control (HWSC) to minimize weed seed input into the soil weed seedbank.
• Herbicide resistance, especially metabolic resistance, in a weed species will not undo itself, and weed plants with the resistance trait are equally as hardy as those weed plants without it. The only sure solution is to ensure there are no viable weed seeds left in a field at the end of the season.
• Dr. Hager discusses 1) Target-Site Resistance (TSR), which is a weed’s genetic mutation that alters the targeted binding site of a herbicide. This type of resistance is promoted by the overuse of the same class of herbicides against a weed species. and 2) NonTarget Site Resistance, which is any type of resistance that does not involve target site alteration. The most concerning type of this resistance is metabolic resistance, where weeds become capable of metabolizing a herbicide active ingredient before it can kill the plant. A weed with this type of resistance can become tolerant to several herbicide classes without having been exposed to them.
• It has been suggested that the popular method of avoiding TSR–namely using a tank-mix of herbicides from multiple classes–may have contributed to the proliferation of weeds with metabolic resistance.
• Bottom Line: 1) Herbicide resistance/development in weeds is here to stay (i.e. there is no reset once a resistant biotype develops) and is becoming more complex, 2) chemical-only weed control may no longer be successful or a viable production practice, and 3) current and forthcoming non-chemical weed control methods such as HWSC will have to be used more and more in the future.
Click here for a White Paper on this website that discusses the general concepts for managing herbicide-resistant weeds.
Composed by Larry G. Heatherly, Jan. 2022, email@example.com