Jarette s Farm Journal

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1 Jarette s Farm Journal Jarette Hurry April 2018 Contact Us For more information regarding any of your farming needs, please feel free to contact the Bertie County Cooperative xtension Office at Your questions and comments are important us. Cotton Planting Decisions Current research conducted in North Carolina indicated cotton yields begin to drop to below early planting levels around 40 days after April 29, which would be after June 10. This data suggest that optimum planting date should be shifted later than earlier. Planning to complete by May 31 should provide a long planting period and an insurance period should replanting be needed. Cotton planting should be completed by June 10 to achieve full yield potential. Deciding when to plant will depend on the weather conditions during mid to late April, since cottonseed is very sensitive to cool soil temperatures during germination. When the cottonseed is absorbing water to begin germination, soil temperatures below 50 F can cause chilling injury and the cottonseed can die if temperatures dip to 41 F. Temperatures below 50 F at about two days after planting may either kill the seedlings or cause growth retardation for weeks into the season. Cotton producers could start planting after April 15 if soils temperatures are 65 F at a 3-inch depth by 10 a.m., and warm, dry weather is predicted for the next 5 to 7 days. Rapid germination occurs at soil temperatures above 70 F and is very slow at temperatures below 60 F. The risk of poor or spotty germination when planting in cold soils is greatly increased under wet conditions. Planting conditions are considered excellent if greater than 50 DD-60s (degree F Max + degree F Min Temp)/2 60= DD-60s) accumulate for the 5 days after planting. Avoid planting cotton if the low temperature is predicted to be below 50 F for either of the two nights after planting.

2 Cotton Burndown By: Charlie Cahoon Most winter weeds are controlled by glyphosate. However, there are some notable exceptions, and it is for these exceptions that we include another herbicide with the glyphosate. That other herbicide is typically 2,4-D although dicamba (Clarity, others), thifensulfuron + tribenuron (FirstShot, Harmony xtra, others), rimsulfuron + thifensulfuron (Leadoff, others), or saflufenacil (Sharpen) are also options. See Table 2 for weeds controlled. It is a common practice to include a residual herbicide in the burndown mixture, especially when horseweed (marestail) is present. Valor (and other brands of flumioxazin) is most commonly used. Valor generally does not help much on killing emerged weeds, hence you still need something like 2,4-D or dicamba. Valor can, however, provide residual control of horseweed and other winter annual weeds that may emerge after a burndown application. This late emergence is usually not much of an issue. Of greater importance is the residual activity on summer annual weeds, such as Palmer amaranth, that emerge after planting. At the 2 oz rate, Valor can control Palmer amaranth for 2 to 3 weeks after planting. If the preemergence herbicides are activated timely, the residual from Valor is of limited benefit. But, in the absence of preemergence herbicide activation, the early season control by Valor can be very important. Goal is being promoted as an alternative to Valor. In my experience, horseweed control by glyphosate + Goal + dicamba or 2,4-D has been very similar to that with glyphosate + Valor + dicamba or 2,4-D. However, we do see a difference in the residual control going into the season. Valor has given us somewhat better Palmer amaranth control between planting and the first POST application than Goal. Waiting periods. The waiting period between burndown application and cotton planting varies, depending upon the herbicide(s) used. Check Table 3 for waiting intervals. Horseweed (marestail) One of the two programs below is suggested for burndown where horseweed suspected to be resistant to glyphosate is present: Glyphosate + 2 oz Valor + 2 pt 2,4-D (this is for typical 3.8 lb/gal formulations) Glyphosate + 2 oz Valor + 8 oz Clarity We generally see excellent kill of glyphosate-resistant horseweed with 2 pt of 2,4-D. However, Clarity (or other brands of dicamba) is sometimes more effective, especially on larger horseweed. Sharpen is very effective on horseweed, but there is a 42-day waiting period between application and cotton planting emerge after planting. levore (halauxifen), a new auxin herbicide from Corteva AgriScience (formally Dow and DuPont), is being marketed for burndown horseweed control. During 2017, NC State and Virginia Tech compared burndown weed control of levore to 2,4-D and dicamba. levore controlled 3.5- and 6-inch horseweed as well as dicamba and better than 2,4-D. However, levore did not effectively control cutleaf eveningprimrose, a common winter annual species in no-till cotton fields. A 30-day waiting period is required following levore applied burndown and cotton planting. Paraquat weeds. Glyphosate is usually the material of choice in preplant burndown, but there are a couple of weeds where paraquat would be preferred. Glyphosate and glyphosate + 2,4-D are weak on Carolina geranium whereas paraquat is quite effective (see Table 2). Glyphosate + dicamba is adequately effective on geranium. The other species where paraquat would be preferred is field pansy. Glyphosate combinations are fair at best on pansy whereas paraquat or paraquat plus diuron work well. Cover Crops. Glyphosate is effective on wheat or rye cover crops (Table 2). If clover or vetch is mixed with the wheat or rye, one needs to include dicamba or 2,4-D with the glyphosate. Vetch is adequately controlled by either 2,4-D or dicamba whereas dicamba is the better material on clover. One of the goals of a cover crop, in addition to erosion protection, is suppression of summer weeds and moisture conservation. Greater weed suppression and moisture conservation will be obtained with greater biomass produced by the cover crop. Hence, growers may want to allow the cover crop to grow later into the spring to produce more biomass. ven so, it is still a good idea to kill the cover crop a week or more ahead of planting to avoid excessive moisture depletion by the cover crop. A good stand of cover crop usually suppresses winter weeds well. However, if the wheat or rye cover crop is thin and winter broadleaf weeds are present, especially horseweed, one can apply 2,4-D or dicamba in March and allow the cover crop to continue to

3 Table 2. Weed Response to Burndown Herbicides for Conservation-Tillage Cotton 1 Weed glyphosate glyphosate + dicamba 2 glyphosate + 2,4-D 3 glyphosate + flumioxazin 4 + dicamba 2 glyphosate + flumioxazin 4 + 2,4-D 3 glyphosate + rimsulfuron + thifensulfuron 5 glyphosate + thifensulfuron + tribenuron 6 glyphosate + Sharpen paraquat paraquat + diuron Annual bluegrass G Buttercups Carolina geranium PF G F G F G G ND G Chickweed Cudweed FG G Curly dock F G FG F FG F ND NP P Cutleaf eveningprimrose PF G FG PF F ND F 8 G 8 Field pansy F F F F F ND F ND G G Henbit G ND Horseweed (marestail) glyphosate-susceptible glyphosate-resistant G N 9 9 G P G P PF PF G G Prickly lettuce P PF Ryegrass G G G G G G G G F FG Speedwell Swinecress FG FG G ND Vetch F FG ND G ND PF F Virginia pepperweed G G G G G ND G G Wheat or rye cover crop 7 G 10 G 10 Wild mustard, wild radish FG G G FG G ND FG G Note: = excellent, 90% or better control; G = good, 80 to 90% control; F = fair, 50 to 80% control; P = poor, 25 to 50% control; N = no control, less than 25% control; ND = no data. 1 See Table 3 for waiting intervals between application and cotton planting. 2 Clarity and other brands. 3 Numerous brands. 4 Outflank, Panther, Rowel, or Valor. 5 Crusher or Leadoff. 6 Audit 1:1, FirstShot, Harmony xtra, Nimble, T-Square, or Treaty xtra. 7 Glyphosate rate is 0.56 lb a.e. for wheat < 12 in. or rye < 18 in., or 0.75 lb a.e. for wheat > 12 in. or rye > 18 in. 8 This level of control requires that the primrose be blooming when treated. 9 This level of control requires 2 pt of 2,4-D. 10 Wheat or rye must have visible seed heads for this level of control.

4 Table 3. Waiting intervals between burndown application and planting of no-till cotton. Active ingredients Brand names Waiting interval 2,4-D dicamba flumioxazin Numerous brands nlist Duo, nlist One Clarity, others ngenia, Fexapan, XtendiMax Outflank, Panther, Rowel, Valor 30 days 0 days, nlist cotton only 21 days after accumulation of at least 1 inch rainfall 0 days, XtendFlex cotton only Minimum of 14 days and 1 inch of rainfall between application and cotton planting when applied at 1 oz/acre; 21 days when applied at 1.5 to 2 oz/acre. If strip-tillage follows application, waiting interval can be reduced to 14 days for the 2 oz. rate. halauxifen levore 30 days rimsulfuron + thifensulfuron Crusher, LeadOff 30 days saflufenacil Sharpen 42 days plus accumulation of 1 inch rainfall thifensulfuron + tribenuron Audit 1:1, FirstShot, Harmony xtra, Nimble, T-Square, Treaty xtra 14 days

5 Couldn t Get in the Field? Applying Nitrogen After GS 30 Nitrogen must be applied in a timely manner to maximize yield potential. Delaying N application after Feekes 6 (Zadoks 31, appearance of the first joint on the main stem) to an N-deficient crop will result in decreased yield potential most years. As plant development advances, yield response to added N progressively declines. After Feekes 9 (Zadoks 39, flag leaf fully developed), there is usually little yield return to added N.

6 Soil Conditions for Corn Planting Corn should be planted when soil temperatures reach 55 F at a 2-inch depth and the long-range weather forecast shows a good chance of warm temperatures. In the coastal plains 55 F soil temperatures usually occur from March 20 March 25. Corn Plant Populations The optimum population for a given situation varies with soil type, hybrid, the ability to supply irrigation water and other management practices. For our area final plant populations should range from 24,000 to 33,00 plants per acre for non-irrigated corn. Populations as high as 43,00 plants per acres are acceptable for irrigated corn. Corn Starter Fertilizer Corn starter fertilizers have been used successfully to increase early plant growth, nutrient uptake, and yields in research trials and on the farm. They also promote earlier maturity, improve southern corn billbug control, and help suppress weeds through earlier shading. Corn starter fertilizer should be placed 2-3 inches away from the seed and 2-3 inches deep the blend should supply lbs./acre of actual nitrogen (N) and phosphorous (P). Remember to stay on the look out for Wheat Pest and Diseases Cereal leaf beetle can be a major insect pest of wheat. The population usually peaks between mid-april and early May. Beetles prefer areas of the field with thin stands and fields that were planted late. ggs laid by adult beetles are about 1/32 inch-long and are easy to spot with little experience. The eggs are elliptical in shape and laid singly or in groups on the upper leaf surface, often along the mid vein. The larval stage, which does the most damage to small grains is a shiny black larva with mucous and fecal matter on its back. Threshold is 25 eggs and /or larvae per 100 stems (tillers). If the proportion of eggs is higher than the larvae count scout again in 5 days. Treat when 50% or more of the eggs have hatched. This insect is fairly easy to control and only requires one insecticide application since there is only 1 generation per year. Several insecticides are labeled for cereal leaf beetle. Army Worms are a sporadic pest of wheat that may appear form late April to mid May. On sunny days they will most often be found under residue. On cloudy days it may be found on the stems of the plants feeding on the foliage or stem itself. A good indicator of activity is the presence of feces on the ground. Also look for feeding damage on the plants and heads lying on the ground. This pest begins feeding at the bottom of plants and works its way upward until it cuts the stem just below the head. Threshold is two 3/8 inch or longer worms per square

7 Powdery Mildew is possibly the most common diseases found in wheat and is usually most active in thick lush areas of the field. Cool and rainy weather will enhance the development of this disease. Temperatures in the range of F favor powdery mildew infestation and development. The disease is slowed significantly when temperatures are above 77 F. Susceptible varieties should be sprayed when 5-10% of the upper leaves are covered with powdery mildew. (Tilt, Propimax, etc.) are generally the most cost effective. Leaf Rust has characteristic red-orange pustules approximately the size of a pinhead that can be found wheat leaves. Leaf rust develops rapidly at temperatures between F. Apply a fungicide when rust covers 1-3% of the upper leaves. Most fungicides labeled for wheat will control this disease. Head Scab infections are influenced by weather in April and early May. Beginning in mid-april you should check the scab risk forecasting website The site allows you to see if the risk of developing head scab is high. If the risk is high and you do not have a variety with moderate resistance, it is wise to apply a fungicide for scab control. The most effective fungicides for head scab are Caramba, Prosaro, and Proline. Application of these fungicides for scab control are only effective at flowering. Do not apply strobilurins such as Quadris and Headline close to flowering as they may increase DON levels. Below is the Head Sab risk tool from Penn State:

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9 Jarette Hurry Bertie County Center North Carolina Cooperative xtension 104 Dundee St., PO Box 280 Windsor, NC mail Cell (252) Office (252) Fax (252) Visit us: Bertie County Cooperative xtension North Carolina State University and North Carolina A&T State University commit themselves to positive action to secure equal opportunity regardless of race, color, creed, national origin, religion, sex, age, or disability. In addition, the two Universities welcome all persons without regard to sexual orientation. North Carolina State University, North Carolina A&T State University, U.S. Department of Agriculture, and local governments cooperating. As a public institution, and instrumentality of the State of North Carolina, NC State University is subject to the NC Public Records laws. This means that records provided to the university may be subject to public disclosure. For more information regarding public records, please visit the Office of General Counsel webpage on public records, accessible at NC Cooperative xtension Bertie County Center 104 Dundee Street PO Box 280 Windsor, NC RTURN SRVIC RQUSTD