Wednesday, April 24, 2024

When To Spot Plant

Jason Woodward
Jason Woodward

Texas Agri-Life Extension
Plant Pathologist

Don’t give up on peanut emergence. Heavy rains fell across much of the Southwestern production region in early May. Some fields were planted before the rains came; however, many growers were waiting for a “planting rain” in hopes to reduce the need to irrigate. The planting rain quickly turned to flash flooding with some areas receiving more than five inches in a 24- hour period. Although the rain was welcome, some producers were forced to rework ground in order to plant or replant where initial plantings may have washed out.

In addition to providing precipitation, the weather systems that moved through the region were also responsible for cool temperatures. Soil temperatures warmed up following these conditions, but peanut emergence may have slowed somewhat. The heavy rainfall after planting may have also caused the seed to settle well below where it was initially planted.

Regardless of the scenario, final peanut emergence should be unaffected, assuming that a high-quality seed lot was planted and seedling disease pressure was low. Much like cotton, peanut plants have an amazing ability to compensate when stand reductions occur. Peanut is different than cotton in that seed are larger, thus they have more energy to break through the ground and come up from deeper depths.

Large areas void of plants after final stands have established may need to be spot planted; however, final plant populations of approximately two and a half plants per foot (uniformly spaced) will not negatively affect yield. In conclusion, don’t give up on peanuts fully emerging without closely inspecting the situation as we all know they can surprise you.

Conditions For White Mold

Scott Monfort
Scott Monfort

University of Georgia
Extension Agronomist

What does an increase in acreage, reduced rotation and warmer-than-normal early season temperatures mean for many Southeastern peanut growers? Elevated disease risk. The disease growers need to be concerned with is white mold caused by Sclerotium rolfsii (pictured below). With many areas of the state already seeing temperatures in the 90s, white mold has the potential to develop early and cause significant damage.

Peanut-Grower-June-2015_Page_21_Image_0004There are several key things growers can do to reduce this threat: 1) Scout peanut fields weekly; 2) Start your soilborne fungicide program early, at 30 to 45 days after planting (DAP) versus 60 DAP; and 3) Be timely with every fungicide application. This will be extremely important for the growers planting peanut in fields with a short rotation sequence between peanut.

Although the early warm conditions can prove to be a problem for white mold, growers need to make sure not to forget about early and late leafspot disease. There has been some indications of a short supply of chlorothalanil (Bravo etc.). With this in mind, growers might need to find an alternative fungicide to provide the needed early season protection against leafspot.

Be Timely In This Busy Month

David Jordan
David Jordan

North Carolina State University
Extension Agronomist

In June, most growers in the Virginia-Carolina region are applying gypsum on Virginia types. Jumbo runners also need gypsum. In many cases, gypsum is applied earlier than needed and this creates some risk if we get heavy rains and soil washes from the fruiting zone at the tops of beds. Having a significant amount of peanut foliage will soften the rain and reduce movement of soil and gypsum from the tops of rows.

Many growers will be making key decisions on herbicides this month. Keep in mind that fields often have ALS-resistant Palmer amaranth , and mixtures of imazapic (several formulations) with Ultra Blazer or Cobra need to be applied to match the PPO herbicides to make sure all of the Palmer amaranth is controlled (small weeds, less than four inches).

While injury from thrips will decrease with time, especially if we have good growing conditions, leaf hoppers can be an issue in many fields given that growers have moved away from chlorpyrifos to control root worms. A well-timed pyrethroid application will control this insect Make sure you treat active populations and not “the visible injury” from previous outbreaks. Growers are also determining whether or not chlorpyrifos is needed for Southern corn rootworm. And while it won’t be needed in many of our fields, using the risk index for this pest, which entomologists in the region developed as an effective tool to help with this decision, can help make sure risky fields are treated. Keep in mind that application of chlorpyrifos under hot and dry conditions, and especially in fields that are at low risk for rootworm damage, can flare spider mites.

The variety Bailey has been planted on close to 80 percent of the Virginia-market type acreage in the region and this variety has a strong disease package. For this reason, in many fields we do not need to start fungicide programs until the R3 stage of peanut growth and maybe even later in some situations. Your Cooperative Extension agent and university pathologist can help with more detail of fungicide programs when we get to early July. In the upper V-C, we have had good success with four-spray programs.

With all that’s going on in June with peanuts, be as timely as possible and anticipate what will happen when you introduce a management practice.

Check That Final Stand

Kris Balkcom
Kris Balkcom

Auburn University
Agri-Program Associate

We seemed to have planted a large percentage of the peanut crop at the same time this year because of early rains, which has the crop a little later with fewer April-planted peanuts. Many producers made good progress in early May, quickly catching up only to be slowed again by the dry weather. As I am typing this article, there is some beneficial rainfall around the area, but we still have several thousand acres to plant. It will be necessary to examine our stands and make sure we have a good stand. If not, there is still time to replant if necessary.

Try to have four plants per foot as a final stand, but research has shown us that with irrigation or good rainfall a stand as low as 2.5 plants per foot has been adequate to make respectable yields. Check your stands quickly, especially since we have planted later, and make sure they are adequate.

Peanut-Grower-June-2015_Page_22_Image_0003Also, with the talk of chlorothalonil being in short supply again, I recommend banding that first and even second application to help stretch that supply out further while the peanuts have a smaller canopy with not much foliage.

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