Late-Season Water Use in Peanut

Water is an issue that has been on everyone’s mind this year and for many of us, it has not been our friend. It was wet early, keeping us from getting in the field for land preparation and planting. Since then, it seems like the only rain we’ve received have come in the form of popup storms. We haven’t had a true ‘rainy day’ all summer in most locations across the state. Having said that, we had a good early pod set and are still set up to have a decent crop, with potential for a good crop if the weather pattern shifts from this point forward. Right now (August 17), a May 12 planted crop is at peak water use, using around 3/10 of an inch of water per day and slightly over two inches per week. Most of us haven’t received anything close to that lately. If rain does begin to pick up, the early wet conditions and resultant late planting could be a blessing in disguise, as a May 22 planted crop is still 1.5 weeks away from peak water use and a June 1 planted crop is still about three weeks away. See the peanut water use graph below.

For those that planted early, don’t abandon hope for big yields. The extreme non-determinate growth habit allows the crop to go through periods of stress and then rebound nicely when favorable conditions return. Keep in mind that depending on conditions, it typically takes 5-7 weeks for a peg that has just entered the soil to become a sound, mature kernel. We are still within a window that a late flush of pods could mean bigger yields at harvest.
From this point until harvest, we want to do our best to make sure the crop is not water limited. Peanut is unique in that it is using almost an inch of water per week right up until digging time. If you have the ability to irrigate, don’t terminate too early. For optimum yield potential, don’t let your crop become drought-stressed from now until the end of the season. Research from Georgia has shown that up to 30% of yield can be made in the last three weeks of the season. Having said that, soil moisture conditions are the most important component at digging time. Over-watering late, in addition to the ever-present chance of a wet fall, can spell trouble at harvest time. This El Nino weather pattern that is threatening to deliver a wet, cool spring has me concerned about peanut harvest. Big yield potential means nothing if we can’t get the crop out of the field. As always, don’t hesitate to call, especially as it gets closer to making harvest decisions. A large percentage of my fall is spent making harvest timing recommendations and I’m always happy to do it.