Navigating The Late Season

What are the factors affecting final sprays and digging decisions?

late leaf spotThe decision of whether to spray or not or when to start digging is not always an easy one. The decision is made more difficult when a storm or bad weather is predicted. Last year’s active hurricane season made end-of-season planning and execution tricky. Based on early season conditions and in case harvest conditions are similar to last year, Clemson University peanut specialist Dan Anco has the following advice.

Changing Planting Dates
Rains over several weeks in May caused some plans to change. Rain brought on late leaf spot to volunteer peanuts. Early pressure calls for early action. As we entered June, there was still time to get peanuts planted and obtain a reasonable window of conditions for growth and harvesting.

Mid-May is generally the best time to plant peanuts in South Carolina, although peanuts can still be made if planted into early June. Once planting dates reach June 10, we are looking at approximate digging dates near Oct. 20 for a 132-day variety like Bailey or digging dates entering into November for moderate-maturity varieties like Georgia 06G.

One of the concerns around that time of year becomes slow drying conditions prior to combining that can lead to quality issues if they sit out in damp conditions too long. Every year is a little different, but overall the combination of lower yield potential, higher late leaf spot pressure and generally unfavorable harvesting conditions are more prevalent for peanuts planted after about June 10.

Harvest Scenarios
At season’s end, if peanut fields are at maturity, they would likely fare better dug and on top of the ground than risk becoming over mature in the ground. This is because of the uncertainty as to when you might be able to get back into the field to dig or to spray for runners that might need more season to fully develop, particularly fields with heavy soils or poor drainage.

If the field is extremely dry to the point where there would be digging losses from hard soil, that complicates things and there is not an easy answer. A lot there depends on how quickly each field might dry out and how mature the pods are currently and if they have time to wait it out.

Peanuts that get rained on for only a day or so should be okay on top of the ground. Without additional rain, what’s above ground will dry out quicker than what’s below ground.

Keep Peanut Protected
On the other hand, if maturity indicates peanuts aren’t ready to be dug, it is important to keep them protected with fungicides until they are ready. Late leaf spot is difficult to slow down once it gets established, especially with defoliation. If defoliation starts to become severe, additional fungicides are usually too late and early digging needs to be considered.

risk factors for late leaf spot