I had a question about whether or not zinc causes J rooting. It became apparent in the conversation that the J rooting was more obvious in areas with low pH soil. The  and the zinc content was relatively low. J rooting is caused by stress. It is typically seen early in the growing season when seed quality is poor and/or conditions for emergence are not ideal. I suspect low pH would cause stress as well. Peanut yield at pH 4.5 is about half that of peanut yield at pH 6.0 (see table 3-3 on page 24 in 2023 Peanut Information. The J rooting is more likely caused by low pH and not by zinc. Split stems are the best indicator of zinc toxicity.