Hopefully, weed issues have been taken care of by the time we move into July. Of course, there will be some weed escapes, and growers are encouraged to be on the outlook for weeds that are generally controlled but have broken through our weed control programs. Of particular concern are Palmer amaranth and common ragweed that have escaped intensive programs that include PPO-inhibiting herbicides (Cobra, Ultra Blazer, Storm, Valor). These escapes could be the first survivors of selection for resistance to this mode of action. Caterpillars and worms can be an issue in July as well. Presence of corn earworms with resistance to pyrethroid insecticides and tobacco budworms that pyrethroid insecticides do not control very well move us toward the more effective yet more expensive products on the market. To get complete control you will need to spend the money. Although spider mites at the time I am writing this (mid-June) have declined, by July things could change and it is important to make sure your insect control practices do not induce spider mite outbreaks.

Next on the list is implementing a solid fungicide program to control leaf spot and southern stem rot diseases. We have numerous options and it is important to look closely at effectiveness, cost, and presence of resistance in your area. Starting with a chlorothalonil treatment, often mixed with Alto, and then follow up with two or three sprays for stem rot and leaf spot control is an effective program in general. The last few sprays need to contain chlorothalonil for late-season protection from leaf spot and resistance management. Weather-based advisories are available in North Carolina to help you fine-tune implementation of your fungicide program. One of our newest programs is Miravis plus either Elatus or Convoy (the latter two are for stem rot primarily, although Elatus provides leaf spot control as well.)  When the higher rates of stem rot materials are used, this fungicide program can provide an entire month of control of both diseases. This is appealing from a logistical standpoint. While expensive, this program is competitive given the length of control it provides relative to other materials. This column could go on and on (especially if written by a plant pathologist), but in brief we have a lot of good options for leaf spot and stem rot control. Keys to success are timeliness of sprays and making sure peanut are protected from the R3 stage of peanut development through the end of the season. In the Virginia-Carolina region, “the end of the season” in which leaf spot is active could be mid-September or it could run well into October. We have seen both scenarios. Protecting vines all the way to digging is critical as this gives us the greatest flexibility in when we dig relative to pod maturity. We can let peanuts reach optimum maturity if vines are healthy and not diseased. We also know that a little bit of disease can increase rapidly and tie our hands and give us less flexibility when it comes to digging. And good leaf spot control starts in late June and July.

As we move through July into August, there will be questions about tank mixing pesticides, micronutrients and the plant growth regulators Apogee/Kudos. Most of our work shows that performance of these products in the mixture is maintained at an adequate level but there are some exceptions. Make sure components of the spray solution stays in place and do not settle before mixing the tank. Keep agitation going and don’t let a tank containing multiple products sit overnight. Your local Extension agent and Extension specialist as well as those in agribusiness who are around mixtures all the time will have information on compatibility of many of the possible combinations that can be applied.