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The Value of Insecticide Seed Treatments in Corn Following Cover Crops

The Value of Insecticide Seed Treatments in Corn Following Cover Crops published on No Comments on The Value of Insecticide Seed Treatments in Corn Following Cover Crops

Cover crops can provide producers a variety of benefits from nutrient cycling and soil cover to nitrogen fixation and pollinator food sources. Cover crops come in many varieties including grasses, legumes and brassicas, however; cover crops maintain a “green bridge” throughout the fall and early spring that may facilitate the movement of pest insects into above and below ground plant structures.

Seedling corn, in Louisiana, is often adversely affected by many factors including excess moisture, cold temperatures and a complex of above/below ground insect pests. The complex of underground insects includes southern corn rootworm, wireworms and white grubs, while the above ground complex includes sugarcane beetles, chinch bugs and cutworms. Most of these insects require a food source that is present in fields for them to successfully overwinter and subsequently begin reproduction when temperatures begin to warm in the spring. The inherent benefits of cover crops often include the presence of large volumes of biomass and an abundant root structure that anchors soil or penetrates a hard pan. Yet, these attributes make cover crops an ideal source for the buildup of yield limiting insects.

Insecticide seed treatments (ISTs) are neonicotinoid based insecticides that coat the outer layer of the seed offering protection from below and above ground early season insect pests. The systemic nature of ISTs make these compounds water soluble and facilitate the vascular movement of the insecticide into the plant tissue. The value of ISTs in Louisiana varies among crops and environmental conditions, most agricultural commodities will usually not benefit from ISTs when planted under optimal environmental conditions (adequate soil temperature, optimal soil moisture and low pest pressure). However, insecticide seed treatments will typically produce an economic benefit when conditions are sub-optimal including very late or early planting, reduced tillage field arrangements, double cropping systems (soybeans behind wheat), pests that are present every year and consecutive plantings (i.e., corn behind corn). In addition to the above mentioned situations, data from the LSU AgCenter’s Macon Ridge Research Station confirmed the need of an IST when corn is planted behind cover crops (Figure 1). A statistically significant increase in yield was observed in corn treated with Poncho 500 IST in Berseen Clover, Crimson Clover and Hairy Vetch while a significantly lower yield was measured in corn planted behind Tillage Radishes treated with the IST (Figure 1). No fungicide seed treatment was used in this study. The measurable difference in yield may be due to the presence of below ground insects that also produced a notable decrease in vigor (Figure 2). Unfortunately for producers, there are no rescue treatments available for below ground insect injury in corn or any other agriculturally managed crop in Louisiana. Therefore, the use of an IST can help safely and effectively control below above and below ground insect pests in corn planted behind cover crops.

Figure 1. Yield of corn treated with Poncho 500 IST vs non-treated following cover crops.
Figure 1. Yield of corn treated with Poncho 500 IST vs non-treated following cover crops.

Aside from the use of ISTs, there are other management practices that can be done to minimize the effects of pest insects, from cover crops, on corn. Burning down cover crops in a timely fashion (6 weeks before planting) will provide enough time for available biomass above the soil to dessicate and force any harbored insects off of the plants. Yet, this timing may not allow enough time for below ground insects to cycle out or succumb to a lack of forage. Earlier burn down timings and the use of minimum tillage may allow enough time for insects to cycle out or be physically removed or destroyed with implements. If you elect to destroy your cover crops earlier than intended, check with your local NRCS representative or LSU AgCenter county agent to ensure enough time has passed that your preplant intentions are met (ie. Nitrogen fixation, nutrient cycling, etc.).

Figure 2. Vigor of corn treated with Poncho 500 IST vs non-treated following cover crops.
Figure 2. Vigor of corn treated with Poncho 500 IST vs non-treated following cover crops.

The use of ISTs is a best management practice recommended by the LSU AgCenter and will help ensure your crop is protected from yield limiting insects. The use of ISTs is highly recommended if you choose to plant corn behind cover crops particularly Berseen Clover, Crimson Clover and Hairy Vetch. If you have any questions or concerns please contact your local LSU AgCenter extension service.

Louisiana Pollinator Cooperative Conservation Program

Louisiana Pollinator Cooperative Conservation Program published on 1 Comment on Louisiana Pollinator Cooperative Conservation Program

The Louisiana Pollinator Cooperative Conservation Program (LPCCP) has been established to foster cooperation among bee keepers, pesticide applicators and agricultural producers for the purpose of preventing honey bees and pollinators from the unreasonable exposure to pesticides through education and stewardship recommendations in the state of Louisiana.

Cooperative Stewardship Recommendations Adopted by the Louisiana Pollinator Cooperative Conservation Program

Active and Open Communication Between Farmers, Applicators and Beekeepers:

Beekeepers, farmers and applicators are encouraged to cultivate and maintain open communication between all parties involved in cooperative activities concerning farming and beekeeping. Farmers, beekeepers and applicators should exchange contact information with one another to facilitate a strong level of communication that should be present in any partnership. Basic information should include: name, telephone number (cell and home), hive locations on the property, agricultural and non-agricultural commodities grown in fields adjacent to hive locations, and information regarding the pesticides applied on these commodities or areas and application timings throughout the growing season.

“Bee Aware” Flag:

The LPCCP has elected to adopt Mississippi’s “bee aware” flag to clearly identify hive locations adjacent to an agriculturally managed crop or area. The “bee aware” flag was developed by the Mississippi Farm Bureau to increase awareness of hive locations to farmers, applicators and beekeepers. The use of Mississippi’s “bee aware” flag creates a unified recognition system that is highly visible to pesticide applicators and farmers that manage commodities across state lines. The flags should be placed in an area that is easily visible to aerial and ground applicators and serve as a reminder that bees are in the vicinity and consideration should be taken when making pesticide applications. Farmers and beekeepers should work together in deciding on flag locations so it is visible to both aerial and ground applicators.  Flag ordering information can be found here: http://www.mississippi-crops.com/wp-content/uploads/2014/03/Bee-Aware-Order-Information.pdf

Hive Locations and Placement:

Hive location is an important consideration that should be discussed between farmers and beekeepers. Farmers are very familiar with their property, equipment and areas that may offer a natural refuge from accidental exposure to pesticides, while beekeepers know the best habitats for bee yards, appropriate orientation of hives so the opening is not directly facing an agricultural field and areas that are easily accessible to beekeepers to facilitate honey collection and hive transportation. Farmers and beekeepers should discuss apiary locations and bee yards that are acceptable for both parties.

Hive GPS Locations:

Beekeepers should make every effort to establish GPS coordinates of their hives and provide this information to the farmer and his applicator to establish precise hive locations on farm property.

Hive Identification and Bee Flag Placement:

Beekeepers are strongly encouraged to place visible placards on at least one hive that provides contact information in case of an emergency or if an issue arises. The placard should clearly indicate the owner of the hives and should be visible from a distance. Farmers should work with beekeepers in selecting the best location for placement of the bee flag so it is visible to ground and aerial applicators. The LPCCP strongly encourages all beekeepers commercial and hobby to register their hives with the LDAF.

Applicator Awareness of Hive Locations:

The farmer should make every effort to notify his employees of apiary locations and related bee flags on farm property.  Farmers should also notify contractual parties and aerial applicators of apiary locations and related bee flags as well.

Annual Apiary Location Review:

Farmers and beekeepers should annually review hive locations on farm property. This is especially important if an accustomed apiary location is moved to a new location on farm. Physical locations on a map or pinned locations on a smart phone may help facilitate this process.

Pesticide Application Timing

Farmers and applicators should consider applying pesticides to areas immediately adjacent to hives as late in the afternoon as possible. Most honey bees have ceased foraging by late afternoon (3 pm) and late applications will help reduce many risks of bee injury. Pesticide applications should only be made when wind conditions are blowing away from colonies and bee yards. Label guidelines should always be followed and applications should only be made when an economic threshold is met.

Sorghum Midge and White Sugarcane Aphid Concerns

Sorghum Midge and White Sugarcane Aphid Concerns published on 3 Comments on Sorghum Midge and White Sugarcane Aphid Concerns

David Kerns and I have been receiving numerous phone calls this week about problems with applications of pyrethroids tank mixed with Transform for control of midge and white sugarcane aphid. The use of a pyrethroid for control of sorghum midge is a common practice in Louisiana; however, pyrethroids are very toxic to beneficial insects and are very likely to flare white sugarcane aphids in grain sorghum. Co-appliations of Transform and a pyrethroid have led to white sugarcane aphids recolonizing fields very rapidly and often resulting in poor control of aphids overall.

Therefore, automatic insecticide applications for midge should be avoided, and applications should only be made if midge are present.  The Louisiana threshold for midge in sorghum is at 25 – 30% bloom, treat for one or more midge per head.  If midge and sugarcane aphids are present, tank mixed applications of chlorpyrifos and Transform will offer good midge control while also reducing the risk of flaring aphids. Chlorpyrifos may not be quite as effective as a pyrethroid for sorghum midge and large populations may require a second application 3 – 4 days later.  Transform tank mixed with Dimethoate is another option for midge and aphid control; however, producers should be prepared to follow up with a dedicated midge application 3 – 4 days later.

Also, pyrethroid applications for the headworm complex in grain sorghum are strongly discouraged. Pyrethroid resistance is very common in sorghum webworm and corn earworm in Louisiana, and insecticides such as Belt or Prevathon should be used for headworms. These chemistries are Lepidopteran specific and will not harm beneficial insects or flare sugarcane aphids.

 

Sugarcane Aphids in Sorghum

Sugarcane Aphid Numbers Increasing in Grain Sorghum

Sugarcane Aphid Numbers Increasing in Grain Sorghum published on 1 Comment on Sugarcane Aphid Numbers Increasing in Grain Sorghum

Infestations of sugarcane aphids in boot to heading grain sorghum are increasing in Louisiana. Many of these populations start off small and exponentially increase in a span of 5 to 7 days. Pyrethroid applications for midge control can reduce natural enemy numbers allowing sugarcane aphids to reach damaging numbers faster.  Honey dew produced by sugarcane aphid feeding will give the crop a glossy appearance and large accumulations will often result in sooty mold growth and harvesting issues later season.

Sugarcane Aphid Damage to Pre-boot Sorghum
Sugarcane Aphid Damage to Pre-boot Sorghum

Sugarcane aphids are difficult to control with currently labelled insecticides; however, Louisiana was granted a section18

Sugarcane Aphids in Sorghum
Sugarcane Aphids in Sorghum

emergency exemption for the use of Transform 50WG for the 2014 production season.  Transform applications should be initiated before grain sorghum becomes heavily infested and producers in Texas are making applications at 30% infested plants with 100 to 250 aphids per leaf present. Use lower aphid numbers with increasing stress due to plant water deficit. This treatment threshold appears to be working for Texas growers; however, these recommendations are not supported by university research due to the recent introduction of this pest to grain sorghum in the United States. Transform applications of 1 oz/acre should be used on medium to high sugarcane aphid populations with the largest gallonage per acre (GPA) feasible for applicators (5 GPA by air or 20 GPA by ground). If 1 ounce applications of Transform are not providing adequate control the rate should be increased to 1.5 oz/acre.

2014 Northeast Research Station Pest Management and Crop Production Field Day

2014 Northeast Research Station Pest Management and Crop Production Field Day published on No Comments on 2014 Northeast Research Station Pest Management and Crop Production Field Day
NERS Field Day Flyer
NERS Field Day Flyer

Transform Granted Section 18 for Control of Sugarcane Aphid in Louisiana Sorghum (Forage, Grain or Stover)

Transform Granted Section 18 for Control of Sugarcane Aphid in Louisiana Sorghum (Forage, Grain or Stover) published on No Comments on Transform Granted Section 18 for Control of Sugarcane Aphid in Louisiana Sorghum (Forage, Grain or Stover)

Transform WG Sec 18 Label for Sorghum                                                     Approval Letter With Effective/Expiration Use Dates

Please follow the link above to access the section 18 label.  The link to the approval letter outlines the effective and expiration dates for the use of Transform in sorghum, as well as specifics regarding number of applications and maximum acreage treated in Louisiana.

If you have any questions or concerns about sugarcane aphids or use of Transform in Sorghum please contact:

Sebe Brown at 318-498-1283 (cell) or 318-435-2903 (office)

Dr. David Kerns at 318-439-4844 (cell) or 318-435-2157 (office)

Dr. Julien Beuzelin at 337-501-7087 (cell) or 318-473-6523 (office)

Mid-South Tobacco Thrips Resistant to Thiamethoxam

Mid-South Tobacco Thrips Resistant to Thiamethoxam published on No Comments on Mid-South Tobacco Thrips Resistant to Thiamethoxam

Syngenta has confirmed resistance to thiamethoxam, the active ingredient in Cruiser, Avicta Complete, Avicta Duo and Acceleron N seed treatments in four populations of tobacco thrips collected in the Mid-South.  Early indications suggest that this resistance is confined to the Mid-South.  Thiamethoxam is a widely used seed treatment for cotton, corn, soybeans and rice in Louisiana; however, thrips rarely inflict enough injury to corn and soybeans to cause economic losses

Over the past three years we, as well as our colleagues around the Mid-South, have seen a decline in efficacy of thiamethoxam treated cotton seed against tobacco thrips.  Based on limited information, resistance appears to be confined to thiamethoxam and has not been detected with imidacloprid.

Additionally, current data suggests that resistance to thiamethoxam is limited to tobacco thrips; thus western flower thrips, which occur in high numbers some years in Louisiana, still appear to be susceptible.

A larger resistance screening program will be conducted in 2014 and more information and specifics will provided as production meetings commence in the winter and spring.

Please see the following link by Gus Lorenz for additional information.

http://www.arkansas-crops.com/2013/11/08/cruiser-thiamethoxam-seed-treatment-may-be-ineffective-on-tobacco-thrips-in-cotton/

If you have any questions or concerns, please contact the Sebe Brown or  David Kerns for more information.

Sebe Brown     Cell: 318-498-1283       Office: 318-435-2903

David Kerns    Cell: 318-439-4844     Office: 318-435-2157

 

Section 24c Granted for Acephate in Louisiana Soybeans

Section 24c Granted for Acephate in Louisiana Soybeans published on No Comments on Section 24c Granted for Acephate in Louisiana Soybeans

This special local need label allows soybean producers to apply a maximum of  2lbs (ai/acre) of acephate  per season. The previous maximum was 1.5lbs (ai/acre)  per season.

For more information or if you have any questions or concerns, please contact:

Sebe Brown at 318-498-1283 (cell) or 318-435-2903 (office)

Dr. David Kerns at 318-439-4844 (cell) or 318-435-2157 (office)

Dr. Julien Beuzelin at 337-501-7087 (cell) or 318-473-6523 (office)

Dr. Jeff Davis at 225-747-0351 (cell) or 225-578-5618 (office)

 

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