Peanut Grower Magazine Column for July Jordan Peanut Notes No. 76
July brings a series of decisions that are generally associated with disease management. While herbicides will need to be applied in some fields and there could be outbreaks of foliar-feeding insects (hopefully not spider mites), the key to optimizing yield will be timely applications of effective fungicides. Starting fungicide sprays at the R3 stage of peanut development is the general recommendation in the V-C Region. With the exception of fungicide programs that include Miravis (with either Elatus or Convoy for stem rot control), applying fungicides every two weeks (as long as conditions are favorable for pathogens) is critical. When weather is not favorable for leaf spot to develop (which can be determined using local weather-based advisories), stretching out the days between sprays can reduce expenses and minimize the likelihood of spider mite outbreaks without sacrificing leaf spot control. But we should never leave peanuts unprotected when conditions are favorable for pathogen development and incidence of disease. Even when fungicides are applied in a timely manner and in a way that should keep peanuts protected, we need to select the correct fungicide to do the job at hand. With leaf spot resistance present to several fungicide sites of action, making sure effective fungicides or mixtures of fungicides are applied can make all of the difference. Check with your local Extension agent and specialist to know what levels of resistance might be present in your area and formulate a fungicide program accordingly. In July we often apply Apogee or Kudos. These products prevent internode elongation and minimize growth. Two applications are generally needed. The first goes out at 50% row closure (half of the vines from adjacent rows are touching.) The follow up spray goes out 2 to 3 weeks later depending upon regrowth and weather conditions. Don’t be early on the first spray, and make sure nitrogen is included with the application. While increases in yield and grade can be inconsistent, there are more intangible benefits to using these products. Digging can be easier when rows are more clearly defined, and as peanut plants move through the digger there is less loss of pods. Vines invert more easily and stay in windows (falling over) more often when these products are applied, especially for peanut verities that have a vigorous growth habit (also considered rank growth.) Much of what we do in July and August is setting us up for flexibility and efficiency in digging and harvesting peanut. Our actions now can determine the flexibility we have in September and October. The more flexibility we have the more likely we can optimize yield and financial return, especially with the unpredictable nature of weather.