Knowledge Refresher on Reklemel™ Active

Question 1

What is the ISO chemical common name of Reklemel™ active?

Answer 1

Fluazaindolizine

Question 2

What are some of the symptoms on target plant-parasitic nematodes exposed to Reklemel™ active?

Answer 2

1. Body coiling and other abnormal body postures, such as zig zag, Z or J shapes.
2. Reduced motility followed by total paralysis.

Question 3

How soon do intoxication symptoms occur on target nematodes after exposure to Reklemel™ active?

Answer 3

Intoxication symptoms may begin after a few hours of exposure and normally within 24-72 hours. Mortality is observed within a few days.

Question 4

What is the global formulated product, based on Reklemel™ active?

Answer 4

The main global brand is Salibro™ nematicide (500 g a.i./L SC). Additional brands may be registered in some countries.

Question 5

What are some key attributes of Reklemel™ active?

Answer 5

1. Unique mode of action
2. Rapid root protection
3. True nematicidal activity
4. Low use rate
5. Long-lasting control (depends on various factors such as application rate and method)
6. Fits with a broad range of application technologies
7. Compatible with integrated nematode and soil health management programs
8. Favorable toxicological and ecotoxicological profiles

Question 6

Does Reklemel™ active have quick knockdown activity?

Answer 6

Yes. Target plant-parasitic nematodes show symptoms of slow movement (decreased motility) within hours of exposure. These symptoms progress over the course of several days until eventual nematode death.

Question 7

Does Reklemel™ active offer quick root protection?

Answer 7

Yes, the rapid onset of symptoms such as reduced motility and activity and abnormal body postures prevent affected plant-parasitic nematodes from moving across soil pores to find and infest new roots.

Question 8

Is Reklemel™ active a true nematicide?

Answer 8

Yes. After plant-parasitic nematodes become visibly symptomatic, effects are irreversible even when nematodes are transferred to freshwater for recovery. Plant-parasitic nematodes treated with Reklemel™ active don’t recover and will eventually die.

Question 9

Does Reklemel™ active impact beneficial soil organisms, like beneficial nematodes, earthworms, bacteria, and fungi?

Answer 9

Multiple laboratory studies demonstrate that Reklemel™ active has high compatibility with common species of earthworms, soil mites, springtails, water-bears, and beneficial nematodes, fungi, and bacteria, some of which are sold as commercially available biological products.

Question 10

True or false: Reklemel™ active has insecticidal, fungicidal, and bactericidal activity.

Answer 10

False. Reklemel™ active does not have insecticidal, fungicidal, nor bactericidal activity.

Question 11

True or false: Reklemel™ active has a unique mode of action, different from any other currently available nematicide.

Answer 11

True. While mechanistically unknown, the mode of action of Reklemel™ active is classified as N-UN (unknown) by IRAC and has been shown to be different from fumigants, organophosphates, carbamates, abamectin, fluopyram, fluensulfone, tioxazafen, and new actives that are coming in the future such as cyclobutrifluram.

Question 12

Is Reklemel™ active compatible with biological commercial products?

Answer 12

Yes. Reklemel™ active has been tested and been shown to be compatible with important groups of beneficial fungi and bacteria, many of which are sold as commercial biologicals. It is recommended to check with your local Corteva representative for guidance before directly tank mixing Reklemel formulations with biological products of interest.

Question 13

When will Reklemel™ active most commonly be applied?

Answer 13

Most often, Reklemel™ active will be applied around transplanting time, preferably shortly before or at transplanting for annual crops and at seasonal root flush in permanent crops. Depending on the crop and local labels, in-season applications may also be made to help extend the crop lifespan or to help protect harvest quality and quantity. Always check and follow label recommendations.

Question 14

Should Reklemel™ active be the only nematode management strategy used?

Answer 14

No. A long lasting and successful nematode management strategy should never rely on a single method or product. Reklemel™ active is a high efficacy, compatible addition to a local integrated nematode management program that should include other strategies such as cultural (crop rotation, green manures, composts, etc.), physical (heat, inundation, etc.), and biological tactics.

Question 15

How is Reklemel™ active applied?

Answer 15

Reklemel™ active has broad application technology flexibility. It can be applied via many methods including drip application, soil surface spray incorporated, in-furrow spray, micro-sprinkler chemigation, and transplanting hole drench. Application methods will depend on crop and country. Follow local label recommendations.

Question 16

What plant-parasitic nematode species are highly susceptible to Reklemel™ active?

Answer 16

Highly susceptible species include root-knot nematodes (Meloidogyne spp.), reniform nematodes (Rotylenchulus spp.) and some species of root-lesion nematodes (Pratylenchus spp.)

Question 17

Is Reklemel™ active nematostatic or nematicidal?

Answer 17

The intoxication symptoms of Reklemel™ active are irreversible and eventually lead to nematode death. Thus, Reklemel is a true nematicide and not a nematostatic nematicide.

Question 18

How long does Reklemel™ active protect plant roots?

Answer 18

Many factors can impact duration of control including soil type, application rates and methods, weather conditions, etc. Root protection generally lasts between 20 - 50 days and can allow roots to remain healthy and functional up to 60 – 90 days after an at-plant application.

Question 19

How does Reklemel™ active protect roots from plant-parasitic nematodes?

Answer 19

Reklemel™ active impairs the mobility of target nematode species, preventing them from reaching, infecting, and damaging plant roots. These symptoms are irreversible and eventually kill the nematodes, making Reklemel a true nematicide.

Question 20

What crop groups will be included in the Reklemel™ active label?

Answer 20

On a global scale, Reklemel™ active will be used in a wide range of crops, including annual vegetable, row, perennial, turf, and ornamental crops. The listed crops will vary by country. Consult local labels for specific crop groups.

Question 21

What is the current Mode of Action classification given to Reklemel™ active by IRAC?

Answer 21

N-UN. The mode of action of Reklemel™ active is mechanistically unknown but available data demonstrates it is unique and different from all other commercially available nematicides.

Question 22

Are the symptoms of Reklemel™ active intoxication in target nematodes reversible?

Answer 22

No. Even after transfer to freshwater for recovery, symptoms are irreversible, and plant-parasitic nematodes typically die within a few days.

Question 23

Does Reklemel™ active kill nematode eggs?

Answer 23

At labeled rates and typical soil concentrations, Reklemel™ active does not have ovicidal activity and does not stop egg hatching. Reklemel targets juvenile nematodes upon egg hatching and before they infest new roots.

Question 24

Which of the following are true about Reklemel™ active?

1. It has well-balanced soil mobility
2. It has excellent root zone distribution
3. It has high leaching potential
4. It is compatible with many beneficial soil organisms

Answer 24

1, 2, and 4 are true. Reklemel™ active has well-balanced soil mobility, contributing to its excellent root zone distribution and low leaching potential. Reklemel is compatible with many beneficial soil organisms.

Question 25

When controlling a nematode infection, does Reklemel™ active have curative activity or preventative activity?

Answer 25

Reklemel™ active has preventative activity. Reklemel acts to prevent infective juvenile nematodes from reaching and infecting roots. Once nematodes are inside a root, they are not controlled by Reklemel.

Question 26

Does Reklemel™ active have flexibility to be used on different soil types?

Answer 26

Reklemel™ active is effective on a wide range of soil types including those above 5% organic matter.

Question 27

Is nematicide resistance a common problem?

Answer 27

Nematicide resistance has been observed under lab conditions, but many factors decrease the risk of nematicide resistance under field conditions. Even with a low risk of resistance development under field conditions, Corteva Agriscience and IRAC continue to recommend the implementation of an integrated nematode management program.

Question 28

What is the chemical class for Reklemel™ active?

Answer 28

Sulfonamide. Reklemel™ active is the first and currently the only nematicide under the sulfonamide chemical class.

Question 29

True or false: Reklemel™ active is a soil-applied nematicide.

Answer 29

True. Since Reklemel™ active has contact activity, it must be applied to the soil to reach where target plant-parasitic nematodes are, in the soil pore water around the root zone.

Question 30

What factors may impact the performance of soil applied chemical nematicides like Reklemel™ active?

Answer 30

1. Application rate
2. Soil distribution (water volumes and soil type interactions)
3. Timing - Application synchronization with susceptible nematode life stage(s)
4. Soil mobility
5. Soil degradation rate
6. Nematode population pressure
7. Nematode species

Question 31

What is the typical range of application rates for Reklemel™ active?

Answer 31

Reklemel™ active application rates in proposed labels globally range from about 250 g a.i./ha up to 2.24 kg a.i./ha. Typical application rates in most crops and countries are around 500 – 1500 g a.i./ha

Question 32

Which of the following describe Reklemel™ active?

1. Volatile
2. Systemic in plants
3. Ovicidal activity
4. Contact activity

Answer 32

Only 4 is correct. Reklemel™ active has contact activity. Reklemel is not volatile, is not systemic in plants and does not have ovicidal activity at labeled rates.

Question 33

Is Reklemel™ active crop-safe?

Answer 33

Yes. When used according to the label, Reklemel™ active shows good crop safety.

Question 34

What temperatures are optimal for Reklemel™ active performance?

Answer 34

The toxicological effects of Reklemel™ active are observed at temperatures as low as 4°C (39°F) as well as above 35°C (95°F). However, the “time to effect” can be longer under temperatures that are below the physiological optimum of the target plant-parasitic nematode.

Question 35

Is Reklemel™ active compatible with beneficial insects, pollinators, and aquatic organisms?

Answer 35

When used according to label instructions, Reklemel™ active poses minimal impact to non-target organisms and does not bioaccumulate.

Question 36

What are the main pathways of Reklemel™ active degradation?

Answer 36

Reklemel™ active is stable on soil surfaces and to hydrolysis but quickly degrades when water solutions are exposed to sunlight. In the soil, Reklemel undergoes microbial degradation to several non-nematicidal metabolites and poses a low risk to groundwater.

Question 37

What are some benefits of Reklemel™ active to support crop yield protection?

Answer 37

By protecting crop roots and allowing better water and nutrient uptake, Reklemel™ active may lead to an increase in crop quality and marketable yield. Typically, this increase may range from 10 to 30%. However, it varies greatly depending on nematode pressure and crop type. Besides promoting crop yield and quality, another key benefits of Reklemel are its excellent environmental profile and the low impact to beneficial organisms that play important roles in sustaining soil health over time.

Question 38

True or false: Nematicides, such as Reklemel™ active, can completely eliminate damaging plant-parasitic nematodes from a field.

Answer 38

False. Though Reklemel™ active has very high efficacy, it cannot entirely eliminate plant-parasitic nematodes from the field due to the huge volume of soil colonized by nematodes that does not receive treatment. An integrated nematode management program should be used to keep damaging nematode population levels under sustained control across seasons.

Question 39

Is the Reklemel™ active formulation (Salibro™ nematicide) compatible to tank mix with other products?

Answer 39

Yes. Reklemel™ active and its formulated products are compatible with many fungicides, insecticides, herbicides, and liquid fertilizers. Given the large number of products and combinations, a jar test is always recommended before preparing a tank mix.