Question:

What do you think is causing this with my peanuts? (grower sent an image)

Jordan:

Some of this is calcium deficiency. Did you apply gypsum?

Follow Up:

I didn’t use gypsum. I used the new pelletized gypsum, but I went back to the old gypsum this year. But I just don’t understand it because in that same field, the other side of it was fine.

Jordan:

Going back to gypsum is a good move. The current data I am aware of, and straightforward calculations and knowing solubility of products, show that this product is not a substitute for gypsum. I’m not sure why different sides of the field had a different response. We see that sometimes. Gypsum buffers against variation in soil characteristics and native fertility.

The cost-effective rate of the product you mentioned and the lower water solubility of it compared with gypsum make it unlikely to satisfy the calcium needs of large-seeded Virginia market type peanuts.

Follow Up:

They also had me spray a liquid calcium product. What do you think of it ?

Jordan:

This product and others like it do not bring much to the table. You need a relatively high concentration of a water soluble source of calcium (gypsum) in the pegging zone in July and August and into September for Virginia market types. There is no way around it.