Tobacco and Peanut News

— Written By Al Cochran

Potassium: A tobacco crop removes about 90 pounds of potassium per year and no more than 120 pounds. On medium to fine textured soils, with a K-I of 51 or greater, and less than 10 inches to clay, an average rate of 75 pounds of K20 can be broadcasted prior to bedding in order to meet the potash demands of the crop. To determine the amount of K20 existing in a field, multiply (K-I times 3.484 times 1.2)

Sulfur: If the soil sample was taken in the spring and the S-I is greater than 25, a response is unlikely. A tobacco field that is less than 12 inches to clay and is showing signs of sulfur deficiency, the deficiency is likely to be temporary. A sulfur deficiency misdiagnosed as a nitrogen deficiency will result in excess nitrogen being applied and the crop not responding.

Magnesium: Deficiencies are more likely on soils which are greater than 15 inches of clay. Lower pH levels can also contribute to a higher risk of magnesium deficiency. Fields which are at a higher risk of this deficiency should be sampled 2-3 years after liming. Fields in the coastal plains should have a %Mg of 17 or higher.

During the 2015 tobacco growing season, there were concerns of calcium deficiency. Calcium deficiency was likely seen by bud or tip leaves that had a downward cupping or hooded look. The deficiency typically occurs at flowering and this is the result of rapid growth and often disappears once topping occurs due to the removal of affected tissue and then causes root stimulation. How do we address calcium issues in the field? Collect routine samples in tobacco fields. Top plants as early as possible because topping will stimulate root growth, which increases calcium uptake. Calcium deficiency is transient and will correct itself. Foliar calcium applications are not recommended.

Boron deficiency symptoms are deformed bud, misshapen leaves and twisted bud. This is likely caused by low soil boron, excessive rainfall, and or rapid plant growth. How do we address boron issues in the field? Consider using a base fertilizer material that will supply .25 to .5 pounds of boron per acre. Only apply foliar boron if tissue samples are deficient. A half pound boron per acre in a single application should correct deficiency. Do not over apply boron.

There are many ways and times to make fertilizer applications to tobacco crop. Applying 50 percent at transplanting plus 50 percent at layby often does not supply the nitrogen in a wet year but often supplies too much nitrogen in a dry year. One thing that researchers have studied is to consider making more than two applications. Apply 50 percent at transplating plus 25 percent at layby and 25 percent two weeks after layby with liquid nitrogen if needed. By doing this you can add more nitrogen if needed during wet year or not make the last application during a dry year.

Weed Management
In recent years, there has been an increase focus on weed control in tobacco. The weed seed contamination in exported leaf has been the driver. Many of the weed species are listed on the Chinese governments’s quarantine list. Weed seed contamination is a likely result of mechanical harvesters pulling in entire plants during the harvesting process. Growers should be aware that even when whole plants are removed prior to curing, the seed is often left behind.

The following are practical ways to reduce weed seed in cured tobacco:
•Use an appropriate weed control program. Weed control programs are comprehensive plans that involve the use of labeled herbicides for tobacco production, post-transplanting cultivation, and hand weeding to remove larger weeds that herbicides or cultivation do not control.
•Keep field borders free of weeds. As mechanical harvesters turn around at the end of harvest rows, they can pull up any large weeds that are present.
•Be aware that the high temperature (165°F) reached during the stem-drying phase is not high enough to kill seed.
•If fields display excessive weed pressure during the season, use manual labor to remove them before they begin to develop seed. If seed development does take place, hand removal may spread the seed to tobacco leaves. In addition, once weeds are pulled, remove them from the field as this will prevent the seed bank from being replenished.

Certain herbicides may be soil incorporated or applied to the soil surface before transplanting within seven days after transplanting. Pretransplant-Incorporated or herbicide application to soil surface before transplanting are ways of managing weeds in tobacco.

Spartan 4F has been the formulation for sulfentrazone used for several years in flue-cured tobacco. Sulfentrazone is also sold under the brand name of Spartan Charge, which contains a premix of sulfentrazone and carfentrazone-ethyl, the active ingredient in Aim herbicide. Both Spartan and Spartan Charge are labeled for use in flue-cured tobacco. However, the formulated amount of the active ingredient sulfentrazone is different. Growers should refer to the label as well as the table below for conversion of the rate of Spartan Charge to deliver the correct amount of active ingredient.

Command and Spartan Charge are labeled for soil surface application before transplanting. Before transplanting, knock down the beds to transplanting height and apply herbicides to the soil surface. For best results, knock down the beds as close as possible to the time of transplanting (keeping in mind the worker reentry restriction on the Spartan Charge and Command labels). Do not knock off additional soil during transplanting. Studies have shown that tank mixing Spartan 4F with below-labeled rates of Command can enhance control of large crabgrass when compared to equivalent rates of Command alone. Spartan 4F tank-mixed with half the labeled rate of Command controlled large crabgrass as well as a full rate of Command applied alone. Therefore, not only can tank-mixing Spartan Charge/Command reduce injury to tobacco from Spartan Charge; you can use a reduced rate of Command and still obtain excellent control of large crabgrass.

Rates: Coarse soil apply 4.5 to 5.5 fluid ounces of Spartan 4F/acre (Pre-Transplant)
Fine soils apply 6 to 7 fluid ounces of Spartan 4F/acre (Pre-Transplant
Apply 1.5 to 2 pints Command/acre (PPI, Pre-T, or POST) (Use lower rate if planting small grains after tobacco)

Command and Devrinol are labeled for application overtop of tobacco within 7 days after transplanting. This method provides weed control similar to PRE-T application and offers the flexibility of application after transplanting.

Disease Control
Black shank is a serious field disease. The symptoms of black shank are well known to tobacco growers. Once infection occurs, death usually follows quickly. When stalks are split, the pith often appears blackened and separated into discrete discs. Black shank can be controlled by rotation; resistant varieties destroy talks and roots, plant on wide high bed and cultivate infested fields last. In fields with histories of black shank use all cultural practices. Use Ridomil Gold just before transplanting. Apply again at first cultivation and or layby. Ultra Flourish 2E brand of mefenoxam used at two times the rates of Ridomil may be used in place of Ridomil Gold 4EC brand of mefenoxam. More information about Ridomil Gold and Black shank can be found on page 142 of Tobacco Production Guide.

New 2016 Presidio Label for Black Shank control. The application rate for Presidio will be 4 fl oz/A and no more than one soil application per season can be made. No transplant application can be made. The Re-entry Interval is twelve hours; pre-harvest interval is seven days and rainfast two hours.

There is a new product that can be used in 2016 for black shank control. The new fungicide will be market as Orondis Gold from Syngenta. This product has systemic and translaminar movement and is the first of a new class of fungicides. Only one application per seson can be made of Orondis Gold. Precerably at transplant via the transplant water, but it could be applied at first cultivation or layby. In 2016 the product will be sold as a co-pack of Orondis Gold and Ridomil. The Orondis Gold Case will have four containers, two 48 oz. jugs of Orondis Gold 200 and two 2.5 quart jugs of Ridomil Gold SL. The application rates are 4.8 fl. oz./Acre of Orondis Gold 200 and 8 fl. oz. /Acre of Ridomil Gold SL.

For more information about tobacco production, see the 2016 Flue Cure Tobacco Guide or contact our office at 789-4370.

Peanut Newsletter

New Aldicarb Product For Georgia Growers

There is a new Aldicarb product (formally Temik) that will be on the market for peanuts. The product is MEYMIK 15 G and will be only labeled in Georgia. There is a good chance this will be available for North Carolina for the 2017 season. Temik was a good product and if this new product gives similar results, this will be another option for insect control in 2017.

Propiconazole Taken Off The Market

The European Union has reduced the MRL or residue levels for propioconazole in peanuts. Because of this, the manufactures of Stratego and Tilt have removed peanuts from their label of approved crops to apply this fungicide on. These products are still labeled for other crops just not for peanuts. Growers need to check with their peanut contract companies to see if they can apply product they have on hand.

Soil Zinc Levels For Peanuts

Peanuts are very sensitive to Zinc. Soil levels of over 250 parts per million can cause zinc toxicity problems for peanuts. Manure and chicken litter have high levels of zinc in them. Be very cautious about applying manure products to land that may have peanuts planted on it. Zinc builds up in the soil and does not leach out. Once a field has high levels of zinc, there is nothing that can be done to lower the zinc levels.

EPA Intends To Cancel Registration Of Flubendiamide Products

EPA has informed the industry that they plan to cancel registration of Flubendiamide products. Belt is the common name of this insecticide. Bayer CropScience is appealing this decision. Stay tuned to see if EPA carries out this plan to stop the registration of Belt.

For more information, call Al Cochan at 789-4370.

Written By

Photo of Al CochranAl CochranCounty Extension Director (252) 789-4370 al_cochran@ncsu.eduMartin County, North Carolina
Updated on Apr 19, 2016
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