Gypsum and Heavy Rains

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Question about gypsum and rain: 

I’m a bit concerned about a few growers that applied gypsum the 3rd week of June. Peanuts were about 8″ or so but we’ve had many areas with excessive rains (5-7″) with more anticipated from the arrival of Arthur. Concerned about movement of gypsum into row middles. Should these growers add additional gypsum?

Answer: 

This is certainly a concern and I don’t have a great answer. In part because no one wants to go back through and make a second application and soil tests for virginia types are unreliable compared to tests for small-seeded runners. After the storm pushes through applying a half rate could help if you can convince someone to do so. With 6 inches already since the application and several more over the next day or so one does wonder how much is remaining. I would invest in a half rate. Some areas, depending on the track of the storm, could get 5 inches, so if you add this together you are now up to over 10 inches in a short period of time and this could wash gypsum from the row to middles with small peanuts, and on sandy soils some or much of it could leach through the pegging zone.

One advantage with so many Baileys planted is that it is a small-seeded Virginia type so the calcium requirement is lower than we would have for Gregory and Spain for sure and also for CHAMPS and Sugg. But I would be concerned after that much rain even for Bailey. In fact, during the past two years there have been fields that received 15 or more inches of rain during this time of year and overall fertility seemed to be compromised.

I am going to resend the Peanut Notes from last year on this question.

There is an old adage that “a dry year will scare you to death but a wet year will kill you.” I’ve always thought about that relative to chopping weeds in peanuts but a lot of water creates many concerns other than weed control. If we do get a lot of rain I suspect there will be a flurry of weeds breaking through, so we might have to get busy in July with additional weed control. Last year with the rain we had we worried a lot about disease being a big issue. I think our improved genetics really helped us in that respect and should do so this year. A good dose of rain could really set back any spider mites that are brewing. And I have had a few reports of armyworms/earworms showing up in low numbers, but heavy rains will push them out of the canopy to the soil. Barbara, Rick and I will follow up with issues growers might need to consider after we see what the storm does.

Article first appeared as North Carolina Peanut Note (PNNC-2014-085)