Saturday, October 16, 2021

Be In The Know On Weeds

peter dotray
Texas A&M AgriLife
Extension Weed Specialist

Although we are still a few months from peanut planting, it is a good time to think about principles for successful weed management. Preplant and at-plant considerations are as follows

1. Know your weeds. Successful weed management starts with knowing the types of weeds we need to control. Many weeds look similar, but may respond differently to mechanical and chemical weed control. There are several weed identification references available in print and online.

2. Know what weed control options are available. We generally think of herbicides as the only option for weed control. However, other options include physical (hand pulling and hoeing), mechanical (plowing, cultivation), cultural (seeding date, seed population, row pattern, crop rotation, variety selection), biological (use of insects, mites, and other biological control agents), and prevention (weed seed dissemination by seeding and movement of equipment).

3. Know what your herbicides can and cannot do! Sometimes we fall into the trap that all herbicides are alike. In fact, they can be quite different. Differences may include water solubility (movement in soil), soil activity, length of soil activity, movement within the plant, and spectrum of weed activity. Knowing what our herbicides can and cannot do will help us make better choices. Always carefully read and follow labeled instructions and pay close attention to rotational crop restrictions, weed size, and the addition of spray additives (crop oil concentrate, fertilizer, non-ionic surfactant, etc.).

4. “Yellow” herbicides are a good foundation for weed control. The dinitroaniline herbicides (Prowl, Sonalan, trifluralin) are effective on annual grass and small seeded broadleaf weeds. The success of these herbicides is based on using appropriate labeled rates for your soil type and thorough and uniform incorporation to ensure germinating weeds come in contact with the herbicide prior to emergence.

5. Start with a clean seedbed. Winter weeds and early emerging summer weeds like Russian thistle (tumbleweed) should not be present at the time peanuts are emerging. Early season weed competition can slow peanut growth and compete with the crop for water and nutrients. Tillage and/or burndown herbicides such as paraquat can help us “start clean.”

6. Are additional soil-applied herbicides needed? The yellow herbicides are effective on annual grasses and several small seeded broadleaf weeds, but larger seeded broadleaf weeds such as annual morningglory and wild sunflower will not be effectively controlled. At-plant herbicides such as Valor (flumioxazin) are effective for early season weed control. The most critical time for weed control is the first 4 to 6 weeks after peanut emergence.[divider]

Plan Before Planting

scott monfortThe 2019 planting season is approaching, and many growers are still dealing with the aftermath of 2018. It was a tough year, especially for cotton and pecan growers, but peanuts fared well with an average yield of 4,450 pounds per acre. This was a pleasant surprise as I had our state average estimated at around 4,000 pounds per acre because of disease and nematode problems. The increase in yield means that the industry does not need an increase in peanut acreage in 2019.

The problem for most growers is that low commodity prices for other crops puts pressure to plant a few more acres of peanut. It is still early but I am hopeful cotton prices will go back up, allowing growers to plant more cotton and thus improve their current rotation.

If we remain at the current acreage level or increase slightly, growers need to start preparing for the crop year. In all of the peanut production meetings this winter, growers were encouraged to take care of the basic necessities to make a high-yielding but profitable peanut crop. Growers do not need to spend top dollar to make the crop, but do need to make every dollar count.

First, growers should take soil samples and address any fertility and/or pH issues before the first seed is planted. It is hard to recover from most fertility deficiencies after planting. To reduce the chance of a nitrogen deficiency, growers are recommended to apply an inoculant (Bradyrhizobium) in fields out of peanut for more than three years. I consider an inoculant to be a good investment, typically $6 to $10 per acre and double that on twin rows, even in shorter rotation.

peanuts showing roots Other important items to consider before planting:

Buy Quality Seed! Know your percent germination of the seed so you can properly adjust seeding rates.

Make sure soil temperatures are 68 degrees F in the top 4 inches for at least three days with no chance of a cold snap in the week following planting.

⇒ Use Thimet to control thrips if you are planting early. Thimet is the only insecticide that suppresses TSWV.

Plant 6 seed per foot to obtain a uniform 4 plants or better per foot of row.

Plant seed in good moisture: Not too dry or too wet!

Do not plant into dry, hot soils and then water afterwards. This can lead to erratic germination and emergence. Irrigate 0.25 to 0.5 inches and then plant.

 Calibrate your planter and in-furrow applicators.

Plant at a safe speed. Planting too fast can cause erratic stands.

Call your county agent if you have any questions regarding this information or if you need further information.[divider]

Spread The Risk

kris balkcomWhat a ride the 2018 crop season gave us. We went from the highest of expectations to some of the lowest of lows. We needed moisture and heat units this past fall to finish the late-planted crop, which was because of excessive rainfall in mid-May — the optimum planting date. Fortunately, it looks like we will average around 3,500 pounds per acre on 163,000 acres. This excludes the tonnage that came from across state lines.

This 2018 harvest season will not be easily forgotten. Beginning with Hurricane Michael, we then had continuous pounding rains every three to four days that made harvest a struggle. We received 20-30 inches of rainfall after Hurricane Michael in some locations. Based on the experiences of this past year and the uncertainty of what is around the corner, take advantage of the earliest opportunities, along with the capabilities of these new varieties, and start planting a little sooner.

This past year was the acid test for disease packages in the newest varieties. Producers need to spread their risk, and one way to do this is variety selection. Currently, a very high percentage of the crop is in Georgia-06G. History has shown us that varieties generally last around 10 years, and we have had this one for 13 years now.

At this stage, we could see a downturn, and we have had some cases where 06G has let us down in virus resistance and yield. Variety trials over the past few years have proven that breeders have done their due diligence to provide varieties that will carry us into the next era.

Let’s look at a few of the newest varieties:

Georgia-16HO is a high oleic variety that responds to more intensive management and will stand out on well-rotated land with a “Cadillac” fungicide program.

FloRun 331 peanut variety FloRun ‘331’ a high oleic variety has shown some of the highest yield potential of the newer releases with more disease resistance than 511 and 297.

AU-NPL 17, which is another high oleic variety, may not be at the top of every variety test at every location, but does have one of the most disease resistance packages of any high oleic variety out currently and that alone makes it a great fit in several different regimes across the peanut belt.

ACI 3321 is a new release from Dr. Kim Moore. I haven’t seen this variety as much but it looks and performs similar to AUNPL17.

TifNV-HighO/L, a nematode-resistant variety with high oleic oil chemistry from USDA peanut breeder Dr. Corley Holbrook, demonstrated a lot of merit last year. It was planted all over the state and performed respectably even in areas without peanut root-knot nematode pressure.

Georgia-12Y has normal oil chemistry and continues to have a place in a producer’s tool box, whether it is to cover the ground in vines, spread out the harvest interval, or just trying to make the best yield possible in some tough ground from heavy disease pressure or deep sand. I have seen it rise to the top in several different circumstances.

The biggest drawback with this variety that I have seen is that it doesn’t dry down to harvest like the other varieties. I believe this is not because of the amount of vines, other varieties grow just as much vines, but the limbs seem to be larger in diameter and hold more moisture delaying dry down.[divider]

Timeliness Is Key

David Jordan
North Carolina State University

Many growers are deciding whether or not to continue with their historical plantings or decrease in anticipation of lower contract prices this spring. Those arrangements are made directly by individual growers and shellers. In the V-C region, peanut yield as a whole was off, though not by much, from what we consider the new average of 2 tons per acre.

We had a decent crop even with the challenges during the growing season and at harvest. This has resulted in significant inventory. With lower than hoped for prices, many growers are looking closely at production costs.

Typically, I might say this is a good year to cut back on production in fields that may not yield the best, especially when considering risk and lower prices. This approach would also lead to gains down the road with improved rotations as well in decreasing inventory.

The challenge is limited alternatives to peanuts. At the current time prices are depressed for just about every other crop, and production costs have increased significantly. We encourage growers look at their realistic yield potential and pick the best fields in their rotation plan that will maximize income per acre and minimize overall risk.

With respect to risk, there are corners we simply cannot cut in the production budget. Getting pH to the right level and controlling pests almost always pays a dividend.

One can look closely at the options that are available and shop around, but the basics need to be in place to ensure efficient production. All states have production budgets and the elements listed in those are essential. In grower surveys, we often find that their “keys to success” include timeliness of practices.

In a year with concerns about price and profit margins, being as precise and timely with the practices we know are essential may be the key.

While digging is a long way off, being on time with digging is one of the best examples of how timeliness pays. Being timely with all pesticide applications and other inputs can set the stage for greater yields with similar input costs. While I have been known to point out the obvious, “timeliness makes a big difference over the growing season.”

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