Crop response, weed resistance and drift management

Question 1

crop response

Is Rinskor^TM active selective to registered crops?

Answer 1

Rinskor^TM active is selective to registered crops when applied following product label recommendations. Rinskor applied at the most common broad-spectrum label recommended rate, will offer effective control of susceptible weeds while keeping the adequate crop selectivity.

Question 2

crop response

Can Rinskor^TM active be used for weed control on all major types of rice?

Answer 2

Yes, Rinskor^TM active can be used for weed control on Indica (long-grain), Japonica (medium-grain) and hybrid rice types, showing good selectivity over a wide window of rice stages. Rinskor^TM active also fits well into Integrated Weed Management (IWM) program on Clearfield and Provisia rice, which has been modified to tolerate certain ALS or ACCase herbicides, respectively.

Question 3

crop response

Rinskor^TM active is selective to transplanted rice, but not so to direct seeded rice. True or False.

Answer 3

False. Rinskor^TM active is selective under different rice growing cultures in all major rice production areas globally. Its product line has been successfully used in direct seeded and transplanted rice, either under flooded or irrigated rice growing conditions.

Question 4

crop response

Rinskor^TM active is so safe to rice and other registered crops that no crop response has ever been observed under any circumstance. True or False.

Answer 4

False. Rinskor^TM active can be selectively used on rice and other registered crops. When applied following label directions, growers will see selectivity and expected weed control. In certain circumstances, however, some crop response may appear following application.

Question 5

crop response

What is crop response anyway?

Answer 5

Under some conditions, selectivity is reduced and crops can react with visible symptoms to a herbicide application, including a Rinskor^TM active application, that we know as Crop Response. The reaction (symptoms) observed in the crop can be less or more visible, depending on many factors involving the herbicide, application, crop and environment.

Question 6

crop response

Why should I care about crop response?

Answer 6

The severity of crop response is dependent on the type of chemical, the rate used, variety and planting method of the crop, depth of flood irrigation, environmental conditions and other external factors affecting plant health and the application. Following Corteva’s use recommendations and label use practices will help minimize the occurrence of crop response when making a chemical application.

Question 7

crop response

What are the symptoms that I can see on rice if Rinskor^TM active causes a crop response?

Answer 7

Most common symptoms of rice crop response observed with Rinskor^TM active applications are:
1. leaf yellowing, especially in young plants; 2. leaf rolling, also known as onion leaf, observable mostly in more mature rice plants; 3. leaf rolling can also display a darker green color along the affected plants; 4. plant stunting, also with slight stand thinning in some cases.

Question 8

crop response

Under what conditions does crop response most likely occur on rice?

Answer 8

Crop response is usually observed when rice plants are under levels of stress caused by external environmental factors, when higher than recommended doses are used and/or the application is made outside the recommended rice growth stage.

Question 9

crop response

What is the most commonly used application rate of Rinskor^TM active for control of a proposed spectrum of weeds while maintain sufficient crop selectivity?

Answer 9

Rinskor^TM active will control a broad spectrum of weeds, including Echinochloa species, while maintain sufficient crop selectivity at rates around 30 g ai/ha for foliar applications. The rate might vary according to factors such as weed development stage and weed spectrum, as well as local regulations.

Question 10

crop response

Describe the best practice, in terms of use rate and application, for selective weed control with Rinskor^TM active.

Answer 10

1. Use Rinskor^TM active at recommended label rate. Do not overdose; 2. Avoid overlapping. Properly calibrate and adjust application equipment and application practice so product is evenly distributed in the field; 3. Implement good practices of crop management (including flood irrigation and fertilization) after Rinskor application.

Question 11

crop response

For selective weed control with Rinskor^TM active, what is the best rice growth stage to make an application?

Answer 11

1. Preferably apply Rinskor^TM active on rice >2-3 leaf development stage. Younger rice could be more susceptible to Rinskor^TM active applications; 2. Applications on young direct seeded rice could result in higher crop response vs. transplanted rice, because of enhanced development and vigor of the latter. Do not make applications to young direct seeded rice with exposed roots.

Question 12

crop response

Proper water management is important to prevent or mitigate crop response with a treatment of Rinskor^TM active in rice. True or False.

Answer 12

True. Proper water management will include irrigation conditions for application to saturated soils and re-entering the water as soon as possible after product application to benefit rice health and weed control.

Question 13

crop response

Which environment conditions should I avoid when planning for an application of Rinskor^TM active in rice?

Answer 13

You should avoid environmental conditions that could affect rice health and crop safety. 1. Extreme heat (>35oC) or cold (<15oC) affecting rice normal metabolism; 2. Drastic temperature fluctuations in short time spans (from high to cold or vice versa); 3. Drought conditions affecting normal rice growth and metabolism; 4. Weakened rice due to poor fertilization practices; 5. Weakened rice due to diseases or insects’ attack, or burning or stunting caused by previous herbicides applications; 6. Weakened rice due to long lasting overflooding (deep irrigation) affecting normal rice development and metabolism.

Question 14

crop response

Is there a relationship between Rinskor^TM active selectivity and rice materials?

Answer 14

Yes. Rinskor^TM active selectivity could vary depending on treated rice materials. Some rice hybrids are more sensitive to a Rinskor^TM active application. Special caution should be taken following label recommendations to avoid undesirable crop response levels on those materials. Rinskor^TM active is not approved for weed control in rice sown for hybrid seed production. Do not recommend or approve such product use.

Question 15

crop response

What should I do if I see a rice crop response after an application of Rinskor^TM active?

Answer 15

If after an application such response is observed, management practices oriented to strengthen rice vigor are recommended, including proper and timely fertilizations and proper water management.

Question 16

crop response

How does crop response, if any, observed following a product containing Rinskor^TM active affect my rice yield?

Answer 16

In certain circumstances, some crop response may appear following application. But, in most cases this crop response is transient, and no negative impact to yield has been observed under common circumstances.

Question 17

crop response

Why will rice yield not be affected even if some crop response occurs following a Rinskor^TM active application?

Answer 17

Numerous yield observations carried out at a global level demonstrate that rice has the capacity to overcome these symptoms and keep its regular growing pattern & physiological process to reach the expected yield.

Question 18

crop response

As an overall product stewardship recommendation, Rinskor^TM active should be applied on healthy growing rice, not stressed by external factors, at the recommended approved rate and at the right rice development stage. True or False.

Answer 18

True. Rinskor^TM active applications made correctly under the favorable environmental conditions, and following the correct use recommendations will not present crop response. These applications could result in improved yields thanks to the outstanding weed control achieved by Rinskor^TM active eliminating weed competition and allowing rice to express its maximum yield potential.

Question 19

weed resistance

What is herbicide resistance?

Answer 19

Herbicide resistance is the natural ability of a weed biotype to survive an application of a herbicide that would normally kill it. These biotypes survive herbicide application at doses that usually give effective control of the species.

Question 20

weed resistance

How does herbicide resistance develop?

Answer 20

Once a weed population is exposed to a herbicide to which one or more plants are naturally resistant, the herbicide kills susceptible individuals, but allows resistant individuals to survive and reproduce. With repeated herbicide use, resistant weeds that initially appear as isolated plants or patches in a field can quickly spread to dominate the population and the soil seed bank.

Question 21

weed resistance

Please describe the differences between target site resistance (TSR) and non-target site resistance (NTSR).

Answer 21

Herbicide resistance mechanisms can be classified into target site resistance (TSR) and non-target site resistance (NTSR). TSR can be caused either by the mutation or the overexpression of the target protein. NTSR is less understood, more complex, unpredictable, and can be caused by several factors, such as altered metabolism (conjugation and detoxification); the herbicide is not able to reach its site of action due to reduced uptake/translocation or herbicide compartmentalization/sequestration.

Question 22

weed resistance

What are cross resistance and multiple resistance?

Answer 22

Cross resistance and multiple resistance, either by TSR or NTSR, may also exist if resistance is reported or suspected for herbicides with different MOA. This type of resistance can complicate control strategies and require enhanced practices for effective weed control.

Question 23

weed resistance

What is integrated weed management (IWM)?

Answer 23

Integrated weed management (IWM) is an approach to managing weeds using multiple control strategies/tactics sharing the common objective of effectively controlling economically important weeds. The purpose of IWM is to include many methods in a growing season to allow producers the best chance to control troublesome weeds.

Question 24

weed resistance

Why resistant management is important to Rinskor^TM active?

Answer 24

Rinskor^TM active has been proved to be a powerful, effective tool for the control of a wide range of weeds including driver grass, broadleaf and sedge weeds in rice and other cropping systems. It is critically important to understand how to maximize the use of Rinskor^TM active as an effective weed management tool and how to properly use the product to ensure its long-term viability by helping prevent the development of herbicide resistance, ultimately resulting in higher grower satisfaction.

Question 25

weed resistance

As Rinskor^TM active is an auxinic herbicide and the incidence of resistance to this group of herbicides is relatively low, there is no need to implement a resistance management strategy for it. True or False.

Answer 25

False. Compared with other herbicide families such as ALS and ACCase inhibitors, the incidence of weed resistance to synthetic auxinic herbicides (SAH) is relatively low considering their long-term global application. However, resistance to SAH is gradually evolving and a good understanding of the context and mechanisms of SAH resistance evolution followed by informed resistance management practices is extremely important to sustain the longevity and utility of this important class of herbicides including Rinskor^TM active.

Question 26

weed resistance

Rinskor^TM active have a good fit to integrated weed management (IWM)? True or False.

Answer 26

True. Its high post-emergence efficiency, alternative mode of action, broad spectrum of activity, including resistant weeds and low use rates make Rinskor^TM active an excellent fit in IWM programs.

Question 27

weed resistance

Because Rinskor^TM active is an effective herbicidal tool to manage weeds that have shown to be target-site resistant to ALS, ACCase, quinclorac, propanil and glyphosate chemistries, it must be the only option for weed management under any circumstances. True or False.

Answer 27

False. Although Rinskor^TM active is an effective herbicidal tool to manage weeds that have shown to be target-site resistant to ALS, ACCase, quinclorac, propanil and glyphosate chemistries, it should be used as part of an integrated weeds management program where multiple modes of action are considered to prevent/slow down the development of weed resistance to Rinskor^TM active itself.

Question 28

weed resistance

What would happen if Rinskor^TM active is repeatedly used in the same field?

Answer 28

If herbicides with the same mode of action are used repeatedly in the same field, resistant biotypes may eventually dominate the weed population and may not be controlled by these products. This also applies to Rinskor^TM active.

Question 29

weed resistance

For resistance management purpose, what would be the maximum number of applications of Rinskor^TM active within a single rice growing season?

Answer 29

Generally, do not use more than two applications of Rinskor^TM active or any other HRAC/WSSA Group 4 herbicide within a single rice growing season. Always follow the label instruction to determine the allowed number of applications.

Question 30

weed resistance

I have a field where Echinochloa is hardly controlled by any of the herbicides I have been using and are commercially available. Can I use Rinskor^TM active to effectively control this weed that seems to be resistant to multiple modes of action?

Answer 30

It seems that you are dealing with a case of metabolic multiple resistance, which means levels of control with Rinskor^TM active could also be compromised. The recommendation is to make a small scale application in a portion of your field to verify Rinskor^TM active performance and use Rinskor^TM active as part of an IWM program.

Question 31

weed resistance

What should I do if I see weed escapes in my field after an application of Rinskor^TM active?

Answer 31

If resistance is suspected, treat weed escapes with a herbicide with a mode of action other than HRAC/WSSA Group 4 or use non-chemical methods to remove escapes, with the goal of preventing seed production.

Question 32

weed resistance

I should use 2X label rate of Rinskor^TM active to control hard-to-kill weeds. True or False.

Answer 32

False. The labeled rates are determined based on multi-year studies, with consideration of performance, crop selectivity and resistance management. Therefore, you should use labeled rates, not higher or lower than prescribed, and apply at the right (crop and weed size) application timing.

Question 33

weed resistance

Does application condition have anything to do with resistance management for Rinskor^TM active?

Answer 33

It does. Applying Rinskor^TM active under the appropriate recommended conditions (weed and crop health, soil moisture and irrigation conditions) can ensure the product will deliver its best performance and minimize weed escape. This in turn will reduce the risk if resistance development.

Question 34

weed resistance

What are the recommendations to reduce the risk of weed resistance evolution to Rinskor^TM active?

Answer 34

There are many standard, proven tactics to reduce the development of weed resistance including, but not limited to: using a herbicide program approach with multiple modes of action (including pre and post emergent herbicides), monitoring treated areas for weeds before and after applications, making timely applications of Rinskor^TM active and other herbicides, and implementing other agronomic and cultural practices.

Question 35

weed resistance

Would you please recommend a chemical control program in which Rinskor^TM active serves as a key herbicide while resistance management is appropriately considered?

Answer 35

Rinskor^TM active should be used as part of a herbicide program that incorporates multiple modes of action, including a soil residual pre-emergent herbicide, followed by a post-emergent application containing a pre-mixture or tank-mix of Rinskor^TM active and cyhalofop or penoxsulam. The use of a program helps improve the level and spectrum of control, as well as reduces the potential for resistance development.

Question 36

weed resistance

In addition to chemical control, what are the agronomic and cultural practices that should be considered for resistance management purpose?

Answer 36

The non-chemical portion of IWM and resistance management strategies that help to delay or prevent the development of herbicide resistance include timely field scouting, use of weed free crop seed, active water management, correct weed identification, proper crop rotation, immediate hand-weeding of escaping weeds and false seeding with mechanical weed control.

Question 37

weed resistance

Please tell me a little bit more about field monitoring with consideration of resistance management.

Answer 37

Active field monitoring is important to resistance management because an early detection can help limit the spread of these weed populations and allows for the implementation of alternate weed management practices. The practice include: 1. Scout fields, before planting and before application, to ensure the herbicide and use rates are appropriate for the weed spectrum and weed size present; 2. Scout fields following application for escaped weeds that can be controlled chemically with a different mode of action or with mechanical methods.

Question 38

weed resistance

I should thoroughly clean plant residues from equipment before leaving the fields. True or False.

Answer 38

True. Thoroughly clean plant residues from equipment before leaving fields suspected to contain resistant weeds will reduce the chance of spreading the resistant materials to other areas.

Question 39

weed resistance

Water management is key to the herbicidal performance of Rinskor^TM active, but would not help on resistance management. True or False.

Answer 39

False. Adequate water management is key to reduce weed escapes and helps prevent weed resistance. If water remains in the field at the moment of Rinskor^TM active application, at least 75% of the weed’s foliage should be exposed so product can contact the foliage. For best results, reflooding should occur from 1 to 3 days after application and no later than 5 days after application. Keep water levels consistent throughout the season. Properly manage irrigation water to avoid movement of seeds of resistant weeds across fields. Avoid drought conditions with proper irrigation pre and post Rinskor^TM active application, so Rinskor^TM active can display optimum herbicidal performance.

Question 40

weed resistance

Describe the actions I should immediately take if a nonperformance of herbicides is observed.

Answer 40

Report any incidence of nonperformance of Rinskor^TM active against a particular weed species to a Corteva Agriscience representative. Contact local extension or a crop advisor for IWM and resistance management information.

Question 41

drift

What is pesticide drift?

Answer 41

Pesticide drift is the airborne movement of pesticides from an area of application to any unintended site. Drift can happen during pesticide application, when droplets or dust travel away from the target site. It can also happen after the application, when some chemicals become vapors that can move off-site.

Question 42

drift

Why pesticide drift can pose a potential risk to human and environment?

Answer 42

Pesticide drift can pose health risks to people and pets when sprays and dusts drift to nearby areas such as homes, schools, and playgrounds. Wildlife and plants are also at risk when drift affects natural areas and water sources. Herbicide drift can damage other nearby crops or make them unsellable if the active ingredient is not registered for a particular crop. Pesticide drift also results in wasted pesticide product. EPA estimates up to 70 million pounds of pesticides are lost to drift each year.

Question 43

drift

Describe the principle of drift management for Rinskor^TM active.

Answer 43

Rinskor^TM active straight, as a tank-mixture partner, or as pre-mixes should be applied only when the potential for drift to adjacent sensitive areas (e.g. residential areas, known habitat for threatened or endangered species, bodies of water, non-target crops) is minimal. Always read and follow label instructions as well as local regulations and requirements related to application of pesticides including Rinskor.

Question 44

drift

When preparing for an application with Rinskor^TM active, what are the key factors to consider to minimize drift potential?

Answer 44

To minimize potential for spray drift, consider these factors to decide when and how to apply Rinskor^TM active: 1. Awareness of sensitive surrounding crops; 2. All weather conditions, such as wind direction, wind speed, temperature and relative humidity are consistent with the label; 3. Application method and application equipment settings are consistent with the label; 4. Application equipment are properly calibrated.

Question 45

drift

Please share the most effective way to reduce drift potential.

Answer 45

The most effective way to reduce drift potential is to apply the largest droplets that provide sufficient coverage and control. Applying larger droplets reduces drift potential, but will not prevent drift if applications are made improperly, or under unfavorable environmental conditions.

Question 46

drift

I am planning a backpack/tractor spray with Rinskor^TM active, what are the drift management details I should pay attention to ?

Answer 46

For ground applications, pay attention to: 1. Total spray volume (commonly 10 gallons or more per acre or 94 L/ha, but it may be different across rice geographies); 2. Application pressure (use spray equipment designed to produce large droplet and low-pressure sprays, while ensuring sufficient coverage; 3. Number, orientation & type of nozzles, and application boom (refer to the spray equipment manufacturer’s recommendations); 4. Height of spray boom (no higher than is necessary to produce a uniformly overlapping pattern between spray nozzles).

Question 47

drift

What basic rules should I follow to prevent/minimize drift when making aerial applications with Rinskor^TM active

Answer 47

Here are the basic rules: 1. Use at least the minimum spray volume listed on the label; 2.Use low-drift nozzles or straight-stream nozzles oriented straight back, so the spray is released parallel to the air stream; 3. Use the minimum number of nozzles that provide uniform coverage; 4. The boom length should be 70% or less of the wingspan or 80% of the rotor width; 5. Spray at the lowest safe height to reduce exposure of droplets to evaporation and wind; 6. Applications at a height greater than 3 m (10 feet) above top of the largest plant are not recommended.

Question 48

drift

What is the effect of drone application on drift management for Rinskor^TM active?

Answer 48

Drone application is a new trend in many countries. This method is highly efficient, with less risk of exposure for operators and the potential to save labor/time/water. Due to its early stage of development, however, professional knowledge and skills are relatively low for application service company. To minimize drift risk when applying a Rinskor^TM active product by drone, like other application methods special attention must be paid to the following factors: nearby sensitive crops, weather conditions, and application equipment setting/calibration. Furthermore, different countries may have different requirements that could require frequent updates to the labels. This application method has not yet been approved by many authorities globally, including the United States Environmental Protection Agency.

Question 49

drift

Would you help me understand the relationship between environmental conditions and drift management for Rinskor^TM active?

Answer 49

Environmental conditions are a critical factor to consider when managing drift with Rinskor^TM active applications. They include the followings: wind speed & direction, temperature, humidity, temperature inversions. Please refer to “Rinskor^TM active Technical Bulletin” and “Rinskor^TM active Drift Management ILT” available on Product Technical Information Center for details.

Question 50

drift

I have a crop of tomatoes / cotton / soybeans / sunflowers / vine adjacent to my rice crop that I am going to spray. Rinskor^TM active is formulated with an adjuvant system that does not allow for off target movement so I don’t have to be concerned with potential drift. True or False.

Answer 50

False. Broadleaf crops are particularly susceptible to Rinskor^TM active. All Corteva Agriscience application recommendations should be followed to avoid or minimize drift risk that can affect susceptible neighboring crops. Refer to Rinskor^TM active literatures for more information or ask your trusted Corteva Agriscience advisor.