Using Precision Agriculture to Control Herbicide-Resistant Weeds in Brazil

Region, in red, infested with resistant weeds in Brazil (Embrapa, 2015).

The occurrence of weeds in agricultural fields of grain and fiber production has caused losses to farmers for a long time. With the introduction of resistance genes in cultivated species such as soybean and cotton, many believed that this problem would be solved. In Brazil, glyphosate-resistant soybeans have been cultivated since 2003. But after almost 15 years, the problem with weeds has not been solved and has regained importance, mainly due to the occurrence of glyphosate-resistant weeds. As can be seen in the map, the problem is spreading in the main producing regions of Brazil, mainly in the areas where glyphosate-resistant crops, such as soybean, corn and cotton have been cultivated.

The photo below illustrates a common scene in Brazilian fields, the presence of three species of glyphosate-resistant weeds in the same area (Digitaria insularis, Conyza canadensis, and Eleusine indica), plus a dozen other species, but with a spatial occupation of less than 50% of the total area. Naturally, weeds are not evenly distributed throughout the fields. Most of the time they are aggregated in reeds mainly due to the dispersion form of the seeds. In others, the outbreaks may be very sparse or isolated plants.

Resistant-weeds-in-Brazil
A common scene in Brazilian fields: the presence of three species of glyphosate-resistant weeds in the same area (Digitaria insularis, Conyza canadensis and Eleusine indica), plus a dozen other species.

Due to this spatial variability, there is a great potential for localized herbicide application. Real-time localized weed spraying is based on plant identification by sensor and instant application of herbicide only on the target. The process of identifying a plant is performed by recognizing a reflectance pattern when subjected to a radiation source. In this case, the sensors are generally “active” because they have their own source of radiation, allowing them to work both day and night.

Currently, there are two commercial equipment in Brazil that perform the identification and spraying of weeds in real time: WEEDit and WeedSeeker. For the detection of plants, the first system is based on the technique of detection of chlorophyll fluorescence that is created by the action of a powerful light source, while the second one uses reflectance in two spectral bands. The technology of these tools is not just about the sensors but the extremely fast speed of the valves responsible for opening and closing the nozzles. In the case of WEEDit, Pulse Width Modulation (PWM) technology at a frequency of 60 Hz allows the right rate of herbicide to be accurately sprayed over the weed independent of variations in the speed of the machine. This type of technology can bring potential savings varying from 20% to 90% and is directly proportional to the level of weed infestation in the area.

Another benefit of these types of systems is the possibility of carrying out the applications with a higher frequency. Because it will only be sprayed on the weeds, it is not necessary to wait for all the weeds to germinate and to take the risks of low control due to the presence of weeds out of the right control stage. In addition, waiting may give these plants the chance to produce new seeds, which aggravates the problem for future crops. More frequently applications will naturally reduce the seed bank in the area over the years. There are reports from Australian producers with 98% herbicide savings after 7 years using the technology.

One of the limitations of using these tools lies in the limited ability to differentiate plant species. Both of the aforementioned equipment have adjustable detection limits that allow the targeting of larger or smaller targets, yet without the full capacity to differentiate species. Aiming to solve this limitation, there are technologies being developed and tested at the research level, mainly using pattern recognition in RGB images (leaves format) and hyperspectral cameras (reflectance intensity in specific regions of the spectrum). An example of this type of technology is being developed by the American startup Blue River Technology. Their concept of intelligent machine for viewing and spraying makes use of computer vision and artificial intelligence for the differentiation of plant species and application in real time.

The presence of weeds at different infestation levels within a single field makes it possible to use precision farming tools as a more efficient way of weed control through localized application using the right rates required for each part of an agricultural area. The increase in the occurrence of herbicide-resistant weeds generates a greater demand for these technologies, since the traditional forms of control have high costs and low efficiency. The risk of introduction or selection of new resistant species, associated with the slow development of new herbicide molecules, makes correct weed management increasingly important for the maintenance of a sustainable production system. Localized weed control with sensor identification and herbicide application in real time enables large product savings, as well as reducing impacts on the environment and contributing to reducing the problem in the long term. New technologies must be developed to meet these demands in the coming years, as there will certainly be a huge market to be explored.

Leave a Reply

International Stories
Israel-Irrigation-system-featured-image
InternationalIsraeli Precision Ag Companies Lead in Water Use Efficiency, Ag Technology
August 16, 2017
In the last week, AgriHub, formed by farmers and consultants from Brazil, visited 10 Israeli agribusiness companies, including the Ministry Read More
Lisa-Prassack-Photo-Credit-Weekly-Times-Now
InternationalAgtech: What the Umbrella Term Really Means
August 10, 2017
Acclerator, incubator, start-up, connectivity — the buzzwords of the digital age can be clear as, well, mud, writes Alex Sampson Read More
New-Zealand-Precision-Ag-Tour
InternationalNew Zealand Study Tour to Demonstrate Recent Advances in Precision Agriculture
August 10, 2017
If you’re interested in an intense, week-long immersion in the use of high-tech products and practices in New Zealand agriculture, Read More
Yield Data Image
Data ManagementYield Data: More Than a Pretty Picture
July 13, 2017
It is mid-July, which, for the Australian cotton industry, means that picking is still going on for some growers. A Read More
Trending Articles
Agri-AFC-cotton-baler
Business ManagementBringing a Southern Sensibility to Precision Agriculture
August 7, 2017
Amy Winstead considers herself blessed to have gotten in on the ground floor of precision ag adoption in the Southeast. Read More
Sensors/IoT2017 Yield Monitor Calibration Checklist — Part I
August 4, 2017
With fall harvest a few weeks away for most of the country, ag service providers from every walk of life Read More
Wade-Barnes
Excellence AwardsBuilt By Agronomists: 2017 Award Of Excellence Winner Wade Barnes on the Making of Farmers Edge
August 2, 2017
Farmers Edge President And CEO Wade Barnes reflects on the process of building his company, shortly after receiving the Crop Adviser/Entrepreneur Award during the InfoAg Conference in July. Read More
Data ManagementInfoAg 2017 Recap: Service Providers Take Center Stage
July 28, 2017
As I sit here and ponder just what it was that we all experienced last week, off the top of Read More
Resistant-weeds-in-Brazil
InternationalUsing Precision Agriculture to Control Herbicide-Resistant Weeds in Brazil
July 24, 2017
The occurrence of weeds in agricultural fields of grain and fiber production has caused losses to farmers for a long Read More
Yield Data Image
Data ManagementYield Data: More Than a Pretty Picture
July 13, 2017
It is mid-July, which, for the Australian cotton industry, means that picking is still going on for some growers. A Read More
Latest News
Israel-Irrigation-system-featured-image
InternationalIsraeli Precision Ag Companies Lead in Water Use Effici…
August 16, 2017
In the last week, AgriHub, formed by farmers and consultants from Brazil, visited 10 Israeli agribusiness companies, including the Ministry Read More
Gregoire-tractor
ProfessionalsMechanization Key to the Future of Vineyard Management
August 15, 2017
Precision technology moves at different speeds across different segments of agriculture. For example, technologies like curve compensation, precision spraying, and Read More
Area-of-Interest-Web-Soil-Survey-screenshot
Data ManagementSignificant Updates Made to SoilWeb, Web Soil Survey Pr…
August 15, 2017
Agronomic professionals and technicians dealing with precision farming must understand the soils within the field before writing effective prescriptions.  A Read More
Univ.-of-Illlinois-Palmer-in-soybean1
Business ManagementOpinion: How to Leverage Precision Agriculture to Launc…
August 14, 2017
To continue where my last article left off (which you can check out here), a precision ag company that specializes Read More
Industry NewsFarm Dog Inks Non-Funded Cooperative Agreement with USD…
August 14, 2017
Farm Dog, a pest and disease management platform for growers and agronomists, has entered into a Non-Funded Cooperative Agreement (NFCA) Read More
Lisa-Prassack-Photo-Credit-Weekly-Times-Now
InternationalAgtech: What the Umbrella Term Really Means
August 10, 2017
Acclerator, incubator, start-up, connectivity — the buzzwords of the digital age can be clear as, well, mud, writes Alex Sampson Read More
Spray Drift
Data ManagementJanzen: Data to Play Key Role in Sorting Out Dicamba Di…
August 10, 2017
You would have to live under a rock to not have heard about farmers’ issues with dicamba this growing season. Read More
New-Zealand-Precision-Ag-Tour
InternationalNew Zealand Study Tour to Demonstrate Recent Advances i…
August 10, 2017
If you’re interested in an intense, week-long immersion in the use of high-tech products and practices in New Zealand agriculture, Read More
Data ManagementDuPont Acquires Ag Tech Startup Granular for $300 Milli…
August 9, 2017
DuPont announced that it has signed a definitive agreement to acquire San Francisco-based Granular, Inc., a provider of software and Read More
EventsSDSU Prof to lead Profit-Focused Panel at Upcoming Inno…
August 9, 2017
Convening a day prior to this summer’s Farm Progress Show at the I Hotel in Champaign, IL (about an hour’s Read More
AGCO White planter 9800VE
ProfessionalsAGCO Crop Tour 2017 Features Precision Planting Add-Ons
August 8, 2017
Higher yields and greater returns are the ultimate goals for crop producers. To help corn growers better understand the role Read More
Corn
Business ManagementCrop Pro Insurance Closes $8 Million in Series A Fundin…
August 8, 2017
Crop Pro Insurance today announced the close of an $8 million Series A round of financing co-led by top agriculture Read More
Agri-AFC-cotton-baler
Business ManagementBringing a Southern Sensibility to Precision Agricultur…
August 7, 2017
Amy Winstead considers herself blessed to have gotten in on the ground floor of precision ag adoption in the Southeast. Read More
Satshot imagery
Imagery/SensingImagery in Agriculture: Some Sage Advice
August 6, 2017
SatShot President Lanny Faleide has been a fixture on the remote imagery scene for as long as about anyone still Read More
Blue-River-See-Spray-technology
ProfessionalsHow Blue River’s See & Spray Technology Could Chang…
August 5, 2017
The blistering West Texas heat rocketing towards triple digits, the affable cotton grower trudged across his dusty field and approached Read More
Grower Services & Solutions2017 Yield Monitor Calibration Checklist — Part II
August 4, 2017
(EDITOR’S NOTE: This is Part II of Tim Norris’ Yield Monitor Calibration checklist, Part I of which was published in Read More
Sensors/IoT2017 Yield Monitor Calibration Checklist — Part I
August 4, 2017
With fall harvest a few weeks away for most of the country, ag service providers from every walk of life Read More
Bowles-Farming
ProfessionalsSoil Sampling in 2017: Data Driven
August 4, 2017
Generally speaking, any ag service provider’s most important job is to help grower-customers produce more with less. According to Jill Read More