What is in this article?:
• In some years irrigation has little impact on yield and in some years, at the Georgia facility, it actually decreased yields slightly.
• In the Southeast, irrigation timing and application curves go back to when Florunner was the overwhelming choice of variety.
Still getting big yields
Even though about half the time these peanuts are under some type of drought stress, the grower consistently produces 6,000 pounds of peanuts per acre.
“During the first 10-14 days peanuts have to have adequate moisture, so cutting back during that phase of plant development isn’t an option. If you don’t get a good stand, all bets are off, so we have to give the plants 100 percent of their moisture needs,” Faircloth says.
“In the early parts of flowering, we can cut water by up to 50 percent for 30 days or so. Cutting back to half an inch will be tough, but it will pay off,” Faircloth says. “Once the plant starts to peg and pods begin to develop, the plant will again need that 100 percent of water, so go back to an inch or 1.5 inches per day.
“At the end of the season, the plant doesn’t need as much water, so the grower can cut back a little bit on water. Over the course of the growing season, cutting irrigation water in half for 35 days makes a big impact on irrigation costs.
Cutting water application in half over five weeks saves 3-4 inches of water at a cost of $10 dollars per acre inch and even more than at $4-$5 a gallon for diesel this year.
Over the course of several years and several locations, the best yields came when the plant got 25-50 percent of its water needs, compared to 100 percent of needs either by irrigation or by rainfall.
“To further test the prime acclimation theory, we drought stressed peanut plants starting at day 75 after planting for three weeks. We looked at recovery and it was clear the planned stress actually stimulated the difference in the growth of the plant and boosted yields compared to the plants that had all the water they needed,” Faircloth says.
“The luxury consumers of water, or plants with 100 percent of their water needs supplied, had all the water they needed and didn’t have to work to get it. The drought stressed plants developed better root systems and became more efficient at getting water and ultimately out-performed the plants with access to all their water needs,” he adds.