Weed Wednesday

Smooth Bedstraw: Pretty to Look At, Problematic in the Pasture

Thu, 22 Sep 2022 02:03:41 GMT

As planting season quickly approaches, weeds are plotting their own entrance to the fields. Often an afterthought, experts say smooth bedstraw is a weed to keep an eye on.

Smooth Bedstraw, or False Baby’s Breath, has been a problematic weed in northeastern United States pastures. In states like Wisconsin, Smooth Bedstraw is primarily found growing along roadsides and woodland edges.

Anne Pearce of the University of Wisconsin-Madison’s First Detector Network says the invasive species is easy to spot.

Smooth Bedstraw key characteristics:
1. Squared, smooth stems—as opposed to other straws that have rough stems
2. Smooth, whirled leaves that are stacked in 6 to 8 leaf groups
3. Large clusters of small, white flowers with four petals

For more on Smooth Bedstraw, visit the Wisconsin First Detector Network .

Late-Maturing Soybeans Might Reduce Weeds, Based on Research from Illinois

Thu, 22 Sep 2022 02:03:41 GMT

Are weed pressure and changes in the climate unsurmountable? A new study from the University of Illinois looked at climate variability, yield losses and potential relief measures.

Researchers analyzed several factors leading to soybean yield loss in a 26-year herbicide study conducted across the state of Illinois.

Based on their findings, the researchers say inadequate late-season weed control—what they define as any application below 76%—was responsible for a 48% loss in yields. When drought and heat hit, the research showed high levels of weed control also didn’t stop significant yield loss to weeds.

The researchers say with the vast majority of U.S. soybean growing regions developing into a drier, warmer climate along with herbicide resistance, soybean yields will continue to decrease unless significant improvements are made to weed management systems.

“You need almost perfect weed control to avoid yield losses in hot, dry conditions. Unfortunately, we have a lot of weed escape in soybean,” says Marty Williams, USDA-ARS ecologist and affiliate professor in the Department of Crop Sciences at Illinois.

Martin Williams, the lead author of the study, says later-maturing soybeans might be able to reduce the risk of incomplete weed control in a more variable climate.

Science at Work

A new weed control system may help to fight weeds, particularly broadleaf weeds and grasses.

Bosch high-tech cameras and Xarvio agronomic intelligence are combined in the Smart Sprayer capable of photographing weeds at more than 1,000 per second.

With cameras spanning the entire operating range of the sprayer, the software and hardware identify the weed, signal a set of nozzles to spray the exact product needed on the weeds, and records the information in real time for farmer review within milliseconds.

The joint venture between BASF and Bosch is in the proof-of-concept stage for U.S. growers. The companies hope to have a limited introduction in 2023.

Read more on sprayers:
> Joint Venture Brings ‘Smart Spraying Solution’ To Farmers

WEED WEDNESDAY: How to Recognize Your Enemy

Thu, 22 Sep 2022 02:03:41 GMT

It’s called the “king of weeds” and can be resistant to common herbicides, but before you can fight it you have to be able to identify it. Doctor Christy Sprague of Michigan State University takes us out in the field for a lesson about Palmer amaranth for Weed Wednesday.

Are You Spraying The Right Weeds? Apps Can Help

Thu, 22 Sep 2022 02:03:41 GMT

Attacking weeds early on is key to stopping them from spreading. In order to do that, you need to know what weeds you’re up against. There are several apps available to distinguish which weed you’re fighting, but how accurate are they?

Researchers at Michigan State University (MSU) have been measuring app identification accuracy for four years. This year, the researchers tested eight apps:

1. Picture This
2. Planet Net
3. PlantStory
4. LeafSnap
5. iNaturalist
6. Seek
7. PlantSnap
8. GardenAnswers

All the apps tested used photo recognition software to identify plants, but some tested in the past required more descriptive input from the user, similar to traditional plant keys. The students tested numerous plants at various growth stages.

They say the apps correctly identified anywhere from 11% to 67% of the plants they photographed, while 25% to 80% of the images were partially identified correctly.

According to the researchers, Picture This—found on the Apple App Store and Google Play—came out on top, successfully identifying 67% of the 130-plants photographed. This app has reigned champion in the test for four years in a row.

Grassy varieties proved the most challenging for many apps, with less than 10% accuracy. According to MSU, grasses are difficult to identify using whole plant images, as close inspection of fine structures is often required for grass identification.

MSU researchers say these apps are a great starting point, but it’s important to double-check the results with a trusted source.

Purdue Warns Against Planting Callery Pear Trees

Fri, 13 May 2022 17:28:02 GMT

Callery pear—a commonly planted shade tree—is usually in full bloom this time of year. A tree that was once thought to be an ornamental, low-maintenance decoration, Callery pear is now being banned in some states.

The tree may look beautiful from the outsets, but an up-close look shows some varieties are thorny, making it difficult for humans and wildlife to pass unharmed.

While most Callery pear cultivars are sterile, they can produce viable seeds when they mix with a “volunteer” pear tree. For example, a Bradford pear and another Bradford pear cannot produce viable seeds. However, a Bradford pear and a White House pear can produce viable seeds. Due to this cross-pollination, the “volunteer” trees have been self-seeding far too rapidly.

According to Purdue University, the tree easily spreads to forests and parks, where it crowds out native plants at a rate that has earned it a spot on the invasive species list.

Effects of Callery pear are still being studied, but one thing is clear: The caliper problem will not go away without proper management, says Purdue Extension Intern Danny Thomas.

Thomas shares key identifiers to look for in Callery pears:
1. Symmetrical crown shape
2. Branches sometimes thorny
3. Rotting fish scent during flowering in early spring

Despite the foul smell and the weak branches Callery pear cultivars are still being used to replace the American Elm as America’s street tree of choice.

Most nurseries have removed the tree from sale floors, but the tree is still available in some areas. Purdue advises against Callery pear’s, suggesting native alternatives such as serviceberry, Eastern redbud or flowering dogwood.

More from Weed Wednesday:
> Blue Light: A Proven Weed Destroyer

> Late-Maturing Soybeans Might Reduce Weeds, Based on Research from Illinois

> Giant Salvinia’s Hidden Uses Unlocked by LSU Students

Giant Salvinia’s Hidden Uses Unlocked by LSU Students

Thu, 05 May 2022 13:59:13 GMT

Weeds aren’t just a problem on land, but also in water. One weed continues to pose a major problem in Louisiana waterways.

It is far too common to see waterways in Louisiana clogged by giant salvinia, an invasive aquatic plant native to South America. Chris Mudge, Louisiana State University (LSU) adjunct professor of plant, environmental and soil sciences, has been studying aquatic weeds for several years and has seen just how damaging the plant is.

Upcycle Opportunities

LSU AgCenter Reporter Craig Gautreaux says students in art class are developing at an alternative use for the invasive plant.

“Initially we see a few plants, then it becomes a monoculture, meaning there’s no other plants, native or invasive, that can hang on,” says Mudge. “Then the plant stops things like navigation. Irrigation is blocked. So those homeowners and farmers or nursery owners can no longer use the water anymore.”

Mudge and others have been looking at ways to control giant salvinia. Now, Mudge and Leslie Koptcho, an art professor at LSU, are looking at an alternative use for the noxious plant — making paper for student art projects.

“Instead of stockpiling them and piling them up on the ground and making compost, which they have low nutritional value, why not take them and find alternative uses,” Mudge says. “And that was to make paper out of it.”

Worth the Wait

The papermaking class uses a variety of invasive plants found in Louisiana. It can take several days to make the paper because of the many steps involved, but Koptcho believes using them can shed light on the problems the plants create.

“We really wanted to use invasives and feature invasives this time because — one, it’s part of my research,” says Koptcho. “We really want to look at those aquatic plants that are unique to the region, and they’re posing a real problem for us in Louisiana.”

Koptcho says the class teaches her students about these problems, and in turn, the students can educate others through their art. While she understands upcycling may not solve the problem, Koptcho believes her class is creating awareness through artwork.

More on weeds:
> 7 Tips to Manage Herbicide Supplies
> Late-Maturing Soybeans Might Reduce Weeds, Based on Research from Illinois
> Blue Light: A Proven Weed Destroyer
> From Sawdust to Herbicide Drift Solution

7 Tips to Manage Herbicide Supplies

Thu, 28 Apr 2022 17:14:06 GMT

Post-emergent herbicide supplies can be hard to find this year. To overcome this challenge, make a plan and consider a new approach to weed management.

You might end up using some products for the first time in years or ever. Or, you might need to lean more heavily on soil-applied pre-emergent products.

“We can start out with a good foundation program,” says Christy Sprague, Michigan State University Extension weed specialist. “That will help us to not rely so heavily on those postemergent herbicides that are probably going to be in short supply this year.”

This season calls for staying flexible and coming up with a plan A, B or even C.

“We’re telling customers in the 21 days after planting to have residual post-application out there,” says Scott Stout, Co-Alliance’s protection and seed business manager. “We can’t rely on trying to clean it up like we have in the past. We’re still waiting for some of these key chemistries to come off the line.”

These specialists suggest spraying any breakthrough weeds early — while just 1" to 4" tall — to help keep weeds in check and maximize the effectiveness of the postemergent pass.

Here are management tips to consider implementing this spring:

1. Layer your Approach to Herbicides

Use a soil-applied herbicide around planting and prior to emergence. Add other active ingredients that can target specific problem weed species. Twenty days later, use a postemergence herbicide while weeds are small (shorter than 4").

2. Don’t Cut Rates
Research shows dropping rates drives weed resistance. Even non-resistant weed escapes that go to seed can remain in the soil bank for years.

3. Manage Without Herbicides
Some farmers might choose to implement a mechanical tillage pass rather than a spring burndown. Cover crops can be an option since they hold back weeds. Plant in narrower rows or at higher populations to reach canopy cover more quickly. Soybean populations that get too high, however, tend to see more lodging later in the season.

4. Dial In Perfection
Take time to calibrate your sprayer, make appropriate adjuvant or surfactant selections and then work during appropriate humidity, sunlight intensities, temperatures and time of day. These strategies can make a world of difference in the effectiveness of a product.

5. Add More Water
It takes more time to use but increasing the amount of water sprayed per acre can improve coverage and efficiency. Make sure you’re using sufficient water, per the label, especially for systemic herbicides.

6. Understand Residuals and Rotation
Make sure you factor in chemistry residuals and soil carryover when using a diverse cropping rotation. Different soil types can affect residual performance in different ways.

7. Focus on Plant Health
Maintaining early and midseason fertility and vigor helps plants grow more quickly and shade out weed competition. That means keeping an eye out for plant diseases and defoliating insects. Biostimulants or growth regulators can also be useful in pushing vegetative elongation and biomass growth.

Read More: 16 Ways to Boost Results from Glyphosate

From Sawdust to Herbicide Drift Solution

Thu, 21 Apr 2022 20:30:31 GMT

Adjuvant based on wood waste reduces herbicide drift

By Fred Miller and Rhonda Brooks

Today’s sawdust could be tomorrow’s solution to controlling herbicide drift, thanks to work by two young entrepre-neurs, Joseph Batta-Mpouma and Gurshagan Kandhola.

Their research, while students at the University of Arkansas, has led to a patent-pending, product formulation based on biodegradable cellulosic nanoparticles made from wood waste. The nanoparticles can bind with herbi-cides and prevent off-target movement.

Nanoparticles, as the name implies, are minuscule and range between 1 to 100 nanometers in size. One nanometer is one-billionth of a meter.

For reference, a sheet of paper is about 100,000 nanometers thick. A strand of human DNA is 2.5 nanometers in di-ameter.

HOW IT WORKS

Batta-Mpouma and Kandhola’s plan is for farmers to be able to use the product, recently trademarked as

BioGrip, as an adjuvant in herbicide tank mixes.

BioGrip adds weight to herbicide droplets, causing them to fall faster and more directly on target during field ap-plications. It also prevents volatilization of herbicide active ingredients, so they stay put on the weeds.

Batta-Mpouma and Kandhola are working on the commercial application of the BioGrip through their recently launched company, CelluDot.

The pair developed the product formulation in cooperation with Jin-Woo Kim, professor of biological and agricul-tural engineering for the Arkansas Agricultural Experiment Station, which is the research arm of the University of Arkansas System Division of Agriculture.

FROM WASTE TO TREASURE

The raw material being used to develop the product is wood waste that’s readily available from timber companies, Kim says.

The U.S. timber industry generates 97 million dry tons of waste annually, reports the Department of Energy.

Beyond wood waste, Kim is looking at how rice hulls, other grain husks and straw can be used to develop similar technologies.

“They all have the added advantage of being biodegradable,” he says.

No petroleum-derived surfactants are being used in the BioGrip formulation, enhancing its environmentally friendly footprint.

Kim says the technology used to create BioGrip has many potential applications. In addition to agricultural uses, researchers are evaluating the use of nanoparticles in biomedical and manufacturing industries.

BioGrip is in the early stages of development. The team has received several grants, but commercialization timing has not been determined.