Jordan V_C Peanut News Article (April 2012)
Moving into May and June will bring critical decisions, especially early season weed and insect management. Spotted wilt management will be in place the moment you leave the field, as will the risk of southern corn rootworm. Keep in mind that we recommend that farmers incorporate three of the five items into their tomato spotted wilt management program with planting date, seeding rate, and variety selection being the easiest to incorporate. Tillage system can impact spotted wilt but has a relatively minor impact compared with the other factors. Certainly in-furrow insecticide choice will have a major impact, but most folks have transitioned away from Temik and many are using Thimet or Phorate, and if you are using these products you are already minimizing spotted wilt. With respect to thrips, efficacy of all products other than Temik will be less consistent and thus performance will be less predictable. For this reason be prepared to make an early season application of insecticide to suppress thrips and reduce damage if the in-furrow insecticide does not perform as well as desired. Orthene, for example, can be applied with herbicides as you make that first or second pass across the field to control weeds and minimize damage from thrips.
In many if not most of our peanut fields we need to have an intensive herbicide program early in the season. If you are in conventional tillage I suggest incorporation of Prowl or Sonalan and perhaps some metolachlor (several formulations.) Then, make sure more residual is put out right after planting, and in most instances this will be Valor SX and metolachlor. While Strongarm is also a possibility, rotation restrictions and ALS resistance limit utility of this herbicide. Outlook is also a viable option and performance will be similar to metolachlor. Applying paraquat within the first two weeks after peanut emergence along with Basagran will control weeds missed by preplant and preemergence herbicides. Suring up this application with more residual is also a good idea. With this approach you are able to stagger your residual herbicides and hopefully get activating rain. At this point your control program depends on weed escapes. Always keep in mind that Storm, Cobra and Ultra Blazer need to be applied when weeds are 4 inches tall or less. When mixing Cobra or Ultra Blazer with Cadre to help on ALS resistant weeds, the timing needs to be for the PPO inhibitors and not Cadre. Timing is absolutely critical. Add 2,4-DB in with your broadleaf sprays but save some for application with fungicides. We most likely will have some escapes late in the season and 2,4-DB can go a long way in suppressing weeds such as sicklepod, morningglories and pigweeds. As always, make sure peanuts are free of grasses as we move into the harvest season.
Being timely on application of gypsum is important, but we do tend to apply this product too early side. The last two weeks of June are plenty early. If we go much sooner than this we risk having the material play out by late season, and a heavy rain in early June can wash soil and gypsum into furrows away for the pegging zone. Once plants get some size on them they “soften” the impact of rainfall and help maintain the gypsum in the pegging zone where it is needed. Boron and manganese will be needed, but generally not until mid July. Boron is applied routinely while manganese is generally needed only when deficiency symptoms appear, most due to high pH in certain areas of fields. As with gypsum, applying Lorsban too early can reduce late-season effectiveness. Also, many of our fields do not need Lorsban and this is where the southern corn rootworm index can help. Recall your experiences at the pod blaster from this past fall. If you noticed more damage from southern corn rootworm than anticipated, you may need to consider applying Lorsban in some of those fields (or fields with similar conditions.) But, if you made a mental note of spider mite damage, it may be possible that you are applying Lorsban when it is not needed.
One should always be asking, “If I do this what will happen next.” We are winding down the Integrated Pest Management class at NC State and this question has become a recurring theme. Anticipation of how crops and pests react with each management input will keep you from being surprised and will prevent you from having to be reactive to each situation.
There are many things going on early in the season that need to be addressed in a timely manner. Many of them are predictable while others are not. Be ready to adjust as needed.
Article first appeared as North Carolina Peanut Note (PNNC-2012-012)