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Getting ready to plant – Burndown considerations

Getting ready to plant – Burndown considerations published on No Comments on Getting ready to plant – Burndown considerations

Drs. Daniel Stephenson and Josh Copes

LSU AgCenter

 

 

I have received many calls concerning burndown over the past couple of weeks.  The warm weather we have experienced recently has most farmers itching to get started.  Research has shown that the optimum time to burndown winter vegetation is 4 to 6 weeks prior to planting.  This is primarily to reduce the risk of insect damage to seedling crops.  Think of it this way, winter vegetation in the field is like a buffet for the worms.  Removing the buffet 4 to 6 weeks prior to planting will cause the worms to die or move on to another food source.  If a crop is planted into green or dying vegetation, the possibility of those worms feeding on the seedling crop is very high.  Also, removal of winter vegetation 4 to 6 weeks prior to planting reduces the risk of physical competition between the weed and the crop.  Corn, for example, is determining its yield as it is spiking and if growth is hampered by any physical competition, i.e. weeds, then yield will be reduced.  Acreage that had a burndown application greater than 6 weeks prior to planting may need to be sprayed again prior to planting, especially if a residual herbicide was not applied with the burndown.  The take home message is simple, plant into a clean, weed-free seed bed.

 

Use of residual herbicides tank-mixed with the burndown application is pretty common.  Many herbicides utilized for residual control in a burndown application need to contact bare soil to provide residual.  If a field is completely covered by winter vegetation (cannot see much bare soil), that vegetation will intercept the burndown application cocktail, thus the “residual” herbicide may only act as a foliar herbicide and offer little to no residual herbicide.  Metolachlor or S-metolachlor are examples of herbicides that are tightly bound by plant biomass, so don’t expect residual control if it doesn’t reach the soil surface.

 

Research has shown that glyphosate plus 2,4-D at 1 lb ae/A is the best broad spectrum burndown treatment.  Notice I wrote 1 lb ae/A, not 0.5 or 0.75 lb ae/A.  For a 4 lb ae/gal 2,4-D formulation, 1 lb ae/A of 2,4-D equals 1 quart/A.  In my opinion, this holds true no matter if you add another herbicide like Sharpen, Goal, LeadOff, etc. to the burndown application.  Essentially, if you are going to make the trip to apply the herbicide, why not apply enough 2,4-D that research has shown will kill almost all of the winter weeds Louisiana farmers deal with.

 

If a producer does not want to or can’t use 2,4-D in their burndown application, then the choice of burndown herbicide depends upon weed spectrum.  I’m not going to go through every scenario because there can be many options.  Give your local county agent a call for help in this situation.

 

In conclusion, the main item all consultants and producers need to strive for with burndown is to ensure that any crop is planted into a weed-free seedbed.  Good luck and please call us if you need any help.

The LSU AgCenter Projected 2017 Rice Farm Cash Flow Model is now available.

The LSU AgCenter Projected 2017 Rice Farm Cash Flow Model is now available. published on No Comments on The LSU AgCenter Projected 2017 Rice Farm Cash Flow Model is now available.

 

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The Projected 2017 Rice Farm Cash Flow Model (Click Here) and Instructions (Click Here) are now available.

The Projected Rice Farm Cash Flow Model was developed to assist producers in planning for the 2017 crop year.  The model is an Excel spreadsheet which allows rice producers to enter projected acreage, yield, market price and production cost data for 2017 to estimate net returns above variable production costs and to easily evaluate the impact of changing percent of base planted on net returns.

2016 Louisiana Rice Variety by Parish Survey results are now available

2016 Louisiana Rice Variety by Parish Survey results are now available published on No Comments on 2016 Louisiana Rice Variety by Parish Survey results are now available

LSU AgCenter Extension Agents in rice producing parishes conduct a survey every year to determine the rice varieties which are grown in their respective parishes.  The data is then broken down further into rice classes including long grain, medium grain, special purpose, hybrid, and Clearfield rice acres.  In addition, information about planting methods, reduced tillage acres, and ratoon rice production is included in the survey.  Graphical parish maps and pie graphs are also provided.  This information can be found on the LSU AgCenter’s website by clicking the following links: Tabular Data & Parish Maps or a complete summary by clicking the image below.

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Click here for PDF Summary

Economic Impact of Excessive Rain to Louisiana Agriculture Exceeds 276 Million Dollars

Economic Impact of Excessive Rain to Louisiana Agriculture Exceeds 276 Million Dollars published on No Comments on Economic Impact of Excessive Rain to Louisiana Agriculture Exceeds 276 Million Dollars

Click here to download full report

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Louisiana Rice Notes #9 – 2nd Flood Edition

Louisiana Rice Notes #9 – 2nd Flood Edition published on No Comments on Louisiana Rice Notes #9 – 2nd Flood Edition

The 9th installment of Louisiana Rice Field Notes is now available. This is the second flood edition this week.  This edition covers recommendations on how to proceed with harvest with all of the flood damaged rice, a very important proposed changed to the crop insurance “practical to replant” definition and the final planting dates (FPD) for rice, corn, sorghum, cotton and soybeans, and an important flood recovery meeting in Crowley tomorrow.

LA Rice Notes 9T_Page_1
Click to open

 

Louisiana Rice Field Notes – 2016 Flood Edition

Louisiana Rice Field Notes – 2016 Flood Edition published on No Comments on Louisiana Rice Field Notes – 2016 Flood Edition

The 8th installment of Louisiana Rice Field Notes is now available.  This edition covers potential damage to rice caused by the flood, an estimate of the economic impact of the flood to the unharvested rice crop, effects on the ratoon rice crop, comments and pictures from rice producers and consultants.

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click to view

 

 

Post-harvest Weed Control

Post-harvest Weed Control published on No Comments on Post-harvest Weed Control

Assessment of Weed Control Programs and Post-harvest Weed Control in Problem Fields.

Josh Copes, Donnie Miller, and Daniel Stephenson

 

Assessment of weed control programs.

With corn harvest underway and soybean and cotton fields approaching maturity, this is a great time to evaluate this year’s weed control programs. Things to consider include: what herbicides were applied, when they were applied in respect to crop and weed growth stages, what were weather conditions like before and after application, and what weed species are present after final weed control efforts. In addition, knowing which fields contain glyphosate-resistant weeds and other difficult to control species that escaped control can help us better plan and budget for more effective herbicide programs. These factors will help critically evaluate weed control programs and may offer insights into becoming more effective at herbicide selection, improving application timing, and how environmental conditions may dictate the need for more aggressive weed control tactics in certain fields.

 

Post-harvest weed control.

The time period from corn harvest and the first killing frost can range from 1 to 4 months. The average first frost date in North and Central Louisiana is November 15 and 25, respectively. A lot of money and effort is spent in controlling weeds during the growing season to negate yield loss. With the extended window from harvest to first frost, weeds will continue to emerge and produce seed. Timely weed control practices following harvest (post-harvest weed control) can reduce weed seed return to the soil, thus ensuring fewer weeds to fight in future cropping seasons. Post-harvest weed control is especially important in fields containing herbicide resistant weeds. A good example to illustrate the importance of post-harvest weed management is the ability of glyphosate-resistant Palmer amaranth to produce mature seed in as little as 30 days after emergence during late summer and early fall. Many other grass and broadleaf weeds are capable of setting viable seed in a similar time frame.

For weeds that are present in the field at harvest time, mowing and/or tillage should be conducted as soon as possible upon harvest to ensure viable seed set is eliminated or reduced. Rainfall will influence subsequent germination of weed seed and therefore the need for additional weed control. Furthermore, rainfall following cultivation could increase weed seed germination, however, if the weeds are controlled the soil seedbank would be reduced.

Other methods of weed control include the use of herbicides. Herbicide applications should be targeted from late-September through October when the time period from application to first killing frost is shortened. Multiple herbicide applications for post-harvest control of summer annual weeds should be avoided. Residual herbicides such as S-metolachlor, pyroxasulfone, linuron, and diuron, among others, can be applied in the fall following harvest. However, rotation interval restrictions must be followed and length of residual control will be influenced by soil temperature and saturation. Glyphosate plus 2,4-D and/or dicamba or paraquat plus diuron and/or linuron are some choices for late-fall post-harvest applications. Diuron and linuron will offer soil residual; however, if soil temperatures are warm and rainfall frequent, do not expect long residual from these products. Likewise the lack of rainfall to properly activate residual herbicides to minimize weed germination can negatively impact treatment effectiveness.  Maximize water volume to ensure good weed coverage as this is critical for good weed control, especially for paraquat plus diuron and/or linuron.

To reiterate, weeds are capable of setting viable seed within 30 days after emergence during late summer and early fall. Post-harvest weed control is especially important when combatting glyphosate-resistant weeds such as Palmer amaranth, waterhemp, or johnsongrass. Problem fields should be identified and receive top priority for preventing seed return. Once harvested these problem fields should be mowed or tilled shortly after harvest to prevent and/or reduce seed set. Fields should then be regularly scouted for emerging weeds and additional control tactics applied prior to seed set. This will require close inspection of weed species to determine when they are flowering. Once a weed species is observed flowering a weed control operation should be implemented. Depending on weather conditions following harvest, weed control tactics may need to be implemented approximately every 3 to 4 weeks until a killing frost has occurred. If glyphosate-resistant Palmer amaranth or waterhemp is an issue, a management tactic (i.e. mowing, tillage, herbicide application) should be done every 3 to 4 weeks.

 

If you have any questions please contact us.

Josh Copes

Cell: 318-334-0401

Office: 318-766-4607

jcopes@agcenter.lsu.edu

 

Donnie Miller

Cell: 318-334-0401

Office: 318-766-4607

dmiller@agcenter.lsu.edu

 

Daniel Stephenson

Cell: 318-308-7225

Office: 318-473-6590

dstephenson@agcenter.lsu.edu

H. Rouse Caffey Rice Research Newsletter now avaliable

H. Rouse Caffey Rice Research Newsletter now avaliable published on No Comments on H. Rouse Caffey Rice Research Newsletter now avaliable

This issue contains information on the South American rice miner, the new Provisia rice system, grain spotting and pecky rice, Field Day highlights, north east Louisiana research in 2016, and rice sustainability.Click to open click to open

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