Manganese deficiency is beginning to show up in peanuts. The deficiency is associated with soils with high pH. This can be across entire fields or in sections. In some cases, we see more deficiency where lime application overlaps. The deficiency can be addressed with foliar applications of manganese. Many fields will not need an application, but manganese products are inexpensive, and many growers apply manganese with their first fungicide spray regardless of symptomology.

Here are some general precautions:

Do not mix boron and manganese together.

Avoid mixing 2,4-DB with manganese.

If you have a deficiency on the scale of the image shown on the post, you need to apply products that deliver adequate amounts to correct the issue. And this may take multiple applications. The sooner you correct the issue the more successful you will be.

Look at Tables 3-13 and 3-14 in 2026 Peanut Information. If you have a visible manganese deficiency (boron deficiency will show up at harvest in kernels,) you need to have the equivalent rates of the micronutrients represented by boric acid/disodium octaborate (Table 3-13) or manganese sulfate (Table 3-14.) Look at how much of a liquid product it takes to correct the deficiency relative to these products. The dry materials are aggravating, but the liquids may not deliver what you need at the same price point. If you use the dry materials, make sure they go into solution before you add anything else to the tank.

Manganese and boron applied separately can be mixed with herbicides, fungicides, and/or insecticides. Of course, when you start mixing three or more items (plus adjuvants,) you need to ask around for advice (unless you already have experience.)