Johnston County Ag Report
March 10, 2014
The Johnston County Ag Report is edited weekly by Agricultural Extension Agents at the Johnston County Extension Center. If you have any questions about the content, please call the Extension Center at 919-989-5380.
Tim Britton, Extension Agent – Field Crops
Dan Wells, Extension Agent – Livestock
Amie Newsome, Extension Agent – Horticulture
Shawn Banks, Extension Agent – Horticulture
Bryant Spivey, County Extension Director
Private Applicators Recertification/Safety Classes
The North Carolina Cooperative Extension Service is inviting all private applicators
whose license expires in 2014 to attend one of the last two Private Applicator Pesticide Recertification/Safety classes. These two-hour classes will be held on the following dates:
Monday, March 24, 2014 beginning at 3:30-5:30 PM
Thursday, September 11, 2014, beginning at 6:30-8:30 PM
The classes will be at the Johnston County Ag Center in Smithfield on NC 210 Hwy. Applicators are reminded that licenses expire at the end of the year, but all recertification credits must be obtained before September 30th of the year the license expires. Applicators are asked to bring their Pesticide Credit Report Card with the bar code scan along with them to class. Please call Tim Britton at 989-5380 to check credits.
Soybean Production Meeting-rescheduled again to March 24
The North Carolina Cooperative Extension Service is inviting all growers to attend the soybean production meeting on Monday, March 24, 2014, at 6:00 pm. The meeting will be at the Johnston County Ag Center Auditorium. Soybean varieties, disease management, and weed control will be discussed. A sponsored meal will be served and continuing education credits will be offered for pesticide applicators and for Certified Crop Advisers. Pre-registration is required for the meeting. Please mark your calendar and call the Johnston County Extension Center at (919) 989-5380 to let us know that you are coming.
Interactive Pesticide Training-March 13, 2014
The North Carolina Cooperative Extension Service in Johnston County is inviting all commercial and private applicators, dealers, consultants, and public ground operators to attend an Interactive Pesticide Training class. This two-hour class will be held at the Johnston County Livestock Arena on Thursday, March 13th. The arena is located at 520 County Home Road, Smithfield, NC 27577. The class will begin at 1:00 PM. Please bring your Pesticide Credit Report Card with the barcode to this class. Please call Tim Britton at 989-5380 for more information about the credits to be offered.
Pesticide Exam Schedule-Johnston County
The North Carolina Pesticide exams will be offered on Wednesday, March 26th and Wednesday, August 13th at 1:00 PM at the Johnston County Ag Center. To take the exam, bring valid ID (Drivers License) and calculator.
Pesticide and Household Hazardous Waste Disposal Day- April 26, 2014
Need to clean out the barn, the chemical storage building, pantry, or underneath the sink. On April 26, 2014 North Carolina Cooperative Extension in Partnership with Johnston County Solid Waste and the NCDA will hold a Pesticide and Household Hazardous Waste Disposal Day. The event will take place at the Johnston County Livestock Arena at 520 County Home Road in Smithfield from 8:00 AM to 1:00 PM. Acceptable items include old and unused pesticides, household cleaners, fluorescent (high TCLP mercury) lamps and bulbs from homeowners, and all types of household batteries i.e. Nickel-Cadmium, Lithium, Alkaline and Metal Hydride. In addition, we will be accepting oil base paint only from the public, but not latex. Oil base paint has a volatile organic odor and can only be washed-off with solvent, such as mineral spirits or kerosene. Latex paint, however, will wash-off with water. If the label is still attached, it will indicate oil base vs. latex. Again, we will only be accepting oil base paint and aerosol paints. The latex paint is a non-hazardous household liquid that can be solidified with sand, soil or kitty litter and disposed of in the landfill.
To maintain this potential yield, upper wheat leaves (particularly the flag leaf – the top leaf) need to be healthy. This includes minimal insect feeding and disease development. Weekly scouting is suggested from the last week of March through the grain fill hard dough stage.
Cereal Leaf Beetles
Cereal leaf beetle larvae are leaf feeders. Larvae are slug-like with yellow bodies. Larvae are typically covered with black mucus/fecal matter, giving them a shiny black wet appearance. Larvae eat long strips of green tissue from between leaf veins and may skeletonize entire leaves. Severely damaged fields appear white/frosted when lots of green tissue are lost from upper leaves.
The cereal leaf beetle threshold is 25 eggs and/or larvae per 100 tillers. 50% of the threshold should consist of larvae. If threshold is met, low rates of several insecticides (such as Baythroid, Warrior, Karate Z and Mustang Max) will control this single generation pest.
Fungal diseases include powdery mildew, leaf rust and stripe rust and conditions have been right for the development of these diseases.
Powdery mildew lesions are first noticeable as white, powdery spots on lower leaves and stems. The disease may then progress up the plant. Powdery mildew variety resistance is the most economical control measure. Pay special attention to wheat fields planted to powdery mildew susceptible/moderately susceptible varieties. A fungicide should be applied if powdery mildew reaches 5-10% coverage of the upper leaves.
Leaf rust lesions are small/circular/brown and individually spaced. Stripe rust lesions are small/circular/yellow-orange and merge to form stripes. Leaf rust/stripe rust variety resistance is the most economical control measure. Pay special attention to wheat fields planted to leaf rust/stripe rust susceptible/moderately susceptible varieties. If the variety is rated susceptible/moderately susceptible and 1-3% of the leaf area is covered with lesions, a fungicide should be applied. If the variety is rated resistant or moderately resistant, it likely has adult-plant resistance meaning that although a few lesions will appear, it will not be profitable to apply a fungicide.
Tobacco Transplant Clipping
Clipping is an important practice that increases the number of usable tobacco transplants. Clipping plants correctly improves uniformity. Before clipping your transplants, perform simple maintenance to ensure proper mower operation. Make sure the mower is not leaking any fluids. Clean the mower well to prevent spreading any pathogens and sanitize the deck with a 50 percent bleach solution. It is best to clean the mower between clippings and between houses.
Clipping should begin when the plants are 2 to 2 ½ inches above the tray. The blade should be set at 1 to 1.5 inches above the bud. Clipping too close to the bud will slow growth dramatically resulting in short transplants. Dropped clippings allow pathogens to grow and spread to transplants, therefore, careful collection is essential. Clippings should be dumped at least 100 yards away from the greenhouse to prevent disease.
As tobacco transplanting begins, many tobacco growers are considering what if anything should be added to the transplant water. I will never forget a statement made by Dr. Bill Collins, Retired Tobacco Extension Specialist when he said, “The best thing to put in transplant water is water.” Well, things do change and there are several labeled products today that provide measurable benefits when added to the transplant water. However, the statement by Dr. Collins is a great reminder that there should be good reason for any product that is added to the transplant water. The product must have greater potential benefit and any possible risk of stunting or other phytotoxic effects that it may cause.
Multiple Products in Transplant Water
Many growers are successfully applying insecticides in the transplant water to control aphids, flea beetles, wireworms, and other larvae that attack tobacco. Examples include acephate, imidacloprid (Admire Pro and others), thiamethoxam (Platinum and others), and chlorantroniliprole (Coragen). Others are interested in applying Ridomil Gold SL in the transplant water to help manage Black Shank, and still others would like to apply starter fertilizer to boost early season growth. In addition to these options, there are producers that would like to and have successfully applied 3 or more of these options in the transplant water during 2011 and 2012 without any known issues or concerns. The more products that are used, the greater the potential for phytotoxicity or mixing problems.
So, what if anything should you add to the transplant water? First you must answer the question of what you are trying to achieve with the addition of these products.
Insecticides-Imidacloprid and thiamethoxam are effective tools for managing wireworm, flea beetles, and aphids and transplant water application is a labeled and effective application method. One benefit of this method is a lower risk for stunting when compared to tray drench application. However, the transplant water application may provide less suppression of Tomato Spotted Wilt Virus (TSWV) than tray drench application because the plant must grow and absorb insecticide before the suppression is in effect. NCSU research has shown that Coragen provides control of hornworms and budworms during the first 5-6 weeks after transplanting when applied in the transplant water. Careful scouting to monitor pest levels is always important regardless of what products have been used.
Fungicides-NCSU research has also shown that 4 ounces of Ridomil Gold SL in the transplant water provides similar Black Shank control to 16 ounces applied at first cultivation in some locations. This strategy offers potential savings and possibly improved uptake during the first 1-2 weeks after planting. If there is a history of black shank in the field, a follow-up application mefenoxam between transplant and lay-by can provide further benefit. If there is little history of Black Shank, a long rotation (4 or more years without tobacco), or highly resistant varieties are planted, then Ridomil will have limited value in the transplant water or otherwise.
Starter fertilizers can provide improved early season growth and earlier topping when compared to no starter. However, research has shown that this earliness does not normally result in measurable increases in yield or quality. Does this mean that starter fertilizers do not have a place? No, to the contrary a good crop start is always important no matter what crop you are trying to grow. Good early season growth can facilitate improved cultivation and therefore better weed control. The quicker that tobacco reaches topping, the sooner that it is safe from pests like aphids, budworms, and even reduces blue mold risk. So, early growth is important. When selecting a starter fertilizer, choose a product that provides the most nutrients (Nitrogen-Phosphorus-Potassium) for your money. Application rates should be based on providing approximately 5 pounds of phosphorus per acre. The benefit of starter fertilizers in the transplant water will be even less when a complete fertilizer like 6-6-18 or 8-8-24 is used as the base fertilizer. If 40 pounds of phosphorus is applied in the base fertilizer at or near transplanting, then it is really difficult to justify the extra expense, trouble, and potential risk associated with transplant water fertilizer.
Ultimately, every grower must decide what benefits are needed from transplant water treatments, and decide where to spend their money and effort for the maximum benefit.
Does Starter Fertilizer Result in More Black Shank?
The real short answer is, it can, but you need to know the rest of the story. The attached document contains several graphs that show research on Black Shank conducted by NC State University. Some of this work was conducted in Johnston County near Archer Lodge. The Johnston County test was conducted in 2009, and the same field was previously planted in tobacco in 2007 with a 50% loss to black shank with NC 71. Since NC 71 is a ph gene variety, we can assume that race 1 Black Shank was present, and is probably dominant in the field. From the data, you will notice that varieties that are highly resistant to Black Shank like CC 35, K 346, and SP 236 performed very well without chemical treatments, while NC 196 had 31% Black Shank and K 326 had 46.5% when untreated. The very next chart shows that Ridomil treatments performed very well and reduced disease significantly in NC 196 and K 326. Note that the data were collected on October 1 and the tobacco held very well in the field. Ridomil treatments on the highly resistant varieties (CC 35, SP 236, and K 346) were of limited value because these varieties just did not have much disease to begin with.
The final graph is from a test that was conducted at the Upper Coastal Plain Research Station near Rocky Mount in a very high pressure Black Shank field with continuous tobacco for many years. This field is a Black Shank nursery for research on varieties and other aspects of disease management. In research plots for disease management, we often plant tobacco in the very highest pressure disease situations with little to no rotation. Remember, unlike tobacco growers, our goal is to have disease so that we can learn to manage it effectively. If we plant tobacco, apply treatments, and have no disease, then we do not learn and our time is wasted. So, this data represents a level of pressure that we never expect growers to see in Johnston County.
The data show that the tobacco receiving no starter fertilizer had 68% Black Shank on August 4 while the tobacco that received 10-34-0 in the transplant water had 83% disease. When Ridomil and starter fertilizer was used together, disease was only 54%. It would have been nice to see what Ridomil alone would have looked like but that data is not available. So, why would starter fertilizer make Black Shank worse? The reason has not been proven through research, but it is possible that this can be explained by the growth of a larger root system early in the season. Typically varieties with a smaller root systems are more resistant to disease. Obviously, a large healthy root system is very desirable when disease is not a problem.
So, should you use starter fertilizer, and should you use it in combination with Ridomil? Black Shank is much less of a problem in Johnston County than is Granville Wilt. The ratio of Granville Wilt problem fields to Black Shank fields is probably at least 10 to 1. However, some farms and some fields can have severe Black Shank pressure. If you are having difficulty managing Black Shank and you are using starter fertilizer, then you should consider discontinuing the use of the product. If you have been using starter with good results and Black Shank is not a big concern, then there is really no reason to change. You can even use Ridomil with the starter fertilizer and this will reduce your risk of disease as illustrated by the data.
Mixing and Application-When using any product in the transplant water uniform application is critical. Mixing products in the nurse tank is advisable to avoid mistakes and concentration in the field. Agitation is important to make sure that products are properly mixed and that they stay in suspension. Application equipment should be calibrated to make sure that rates are accurate. Pressure systems rather than gravity flow systems are preferred.
Disease Prevention in Tobacco Greenhouses
This is the time of the year when our greenhouse disease problems normally begin. Monitor plants closely for disease symptoms and ventilate as much as possible to keep humidity as low as possible and prevent any disease development. As clipping begins, do a thorough job of collecting clippings and dispose of clippings at least 100 yards away from the greenhouse. Sanitize mowers before and between clippings with a 50:50 bleach solution to kill any pathogens on the mower.
Soluble Salt Injury in Greenhouses
In the tobacco greenhouse soluble salts injury, sometimes called fertilizer burn, can occur between germination and the time that the plant roots reach the water in the float bed. Fertilizer that is added to potting soil and to the float water can accumulate in the upper portion of the cell as water evaporates from the tray surface. When conditions exist that delay growth and delay plant roots reaching the water before salt concentrations reach high levels, plant injury and even death may occur.
The symptoms of soluble salts injury will be noticed first in the smaller plants. Late germinating plants are typically smaller and have root systems that are shallow when compared to larger seedlings. While all of these small plants may not make useable transplants in the long run, they can be a good indicator that salts are reaching potentially damaging levels. To manage plants for maximum usability, it is important to avoid any condition like high soluble salts that can slow the growth of smaller plants.
The first symptom of high soluble salts on small tobacco seedlings may appear as a slight yellowing. As this problem progresses, the yellowing will grow worse and the lower leaves will begin turning brown at the leaf margin. Eventually, the entire plant will turn brown and die. Since a picture can be worth a thousand words, I have attached 3 images that I took in a greenhouse today. In each picture, the plant in the center is the one that is affected by high soluble salts. When this problem occurs, the larger seedlings will be dark green in color creating a stark contrast.
In addition, the following link will access a document that provides general information about soluble salt injury on crops.
Soluble salt injury may be avoided by selecting potting soil with limited fertilizer added and by delaying fertilizer addition until about 7 days after seeding. However, using these practices does not guarantee protection from soluble salt injury. When soluble salts reach damaging levels, tobacco plants should be wet overtop with enough water to leach salts through the cells. This will probably require 2-3 gallons of water per linear foot of the greenhouse. Once plant roots extend through the bottom of the tray, the risk of salt injury is virtually eliminated.
Water Sampling & Analysis
Water quality management is an important part of successful tobacco transplant production. Bicarbonate levels are high in water from some wells in the Coastal Plain of North Carolina. Additionally, boron levels may not be adequate in some water supplies. Do not assume that water from municipal sources is better for tobacco transplant production. Municipal sources may be acceptable, but they are generally less desirable than on-farm wells. For any source, water quality should be tested annually prior to seeding. The North Carolina Department of Agriculture and Consumer Services analyzes water samples at a cost of $5.00 per sample. Collect approximately 16 ounces of water from each potential source. Plastic drink bottles (16 to 20 ounce) make ideal sample containers. Sample containers should be rinsed several times with plain water before the sample is collected. Water should be allowed to run from the tap for several minutes prior to collecting the sample. You can deliver your water sample to the Johnston County Extension Center and our staff will assist you with the information sheet. A check is the preferred method of payment.
Pesticide Container Rinse and Recycle Program
The pesticide container rinse and recycle program has expanded to two new locations, giving Johnston County more room to properly dispose of pesticide containers.
These sites are located at 820 Stewart Road in Four Oaks, 1096 Scout Road in the Bentonville area, 9349 NC Hwy 96 S in the Meadow area, 5677 US Hwy 301 in Kenly, 15031 Buffalo Road in Clayton, and at the Johnston County Landfill site on County Home Road in Smithfield.
Properly rinsed containers can be taken to these sites during normal operating hours. You do not need a county solid waste sticker to dispose of containers. Remember, to remove the label and lid, on buckets, remove the label and large lid, and on 35 and 55 gallon drums, drill holes in bottom and do not crush.
Beaver Management Assistance Program
Johnston County participates in the beaver management and assistance program conducted by the USDA. County, state, and federal monies provide the program designed to give individual technical assistance and advice to landowners with beaver problems. Property inspection and consultation is free. Consultation may include showing the landowner how to trap beavers and destroy dams.
For work that the USDA actually conducts, landowners will be charged a fee for each visit to the site and a set amount for each dam destroyed. USDA will do all or part of the work.
Interested landowners should call or contact Tim Britton with the Johnston County Cooperative extension service at (919) 989-5380 or by email at Tim_Britton@ncsu.edu.
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