Don’t Wait On Weeds

David Jordan

David Jordan
North Carolina
State University

Depending on weather and field conditions in May, there can be a wide range of peanut sizes and ages moving into June and July. Peanuts in the V-C region most likely will be four to six weeks old in mid-June. Hopefully, herbicide programs used at planting have performed well. The same is true for thrips control. For fields where weeds have escaped, herbicide application timeliness and applying the correct rate of herbicides are keys to success.

Depending on weather patterns and weed emergence, it can be tempting to let a few more weeds emerge with the hopes that one postemergence application will be completely successful. The reality is that weeds keep on growing and waiting for others to emerge creates a challenge, especially for paraquat and PPO-inhibiting herbicides. This often happens when conditions are dry and growers are deciding whether to treat or wait just a little longer. Making the application on time is generally the best thing to do as waiting longer simply allows the weeds to get bigger and more difficult to kill.

In addition to weed control and suppressing thrips if systemic insecticides at planting provided marginal control, growers will be applying gypsum on Virginia market types and in most cases to runner-market types as well. Some fields will also need insecticide to control southern corn rootworm, and fungicide sprays for leaf spot and stem rot are right around the corner (applications in the V-C region begin around the R3 stage of growth, which is often during the first two weeks of July.)

Palmer pigweedDevelop your fungicide programs keeping in mind what worked well in 2017 and what worked poorly. Let peanuts get some size on them before applying gypsum (apply gypsum during the last two weeks of June to avoid washing of soil if we get heavy rains.) In early June, if plant populations are two or less per foot, planting more seed can help, but if you have three or more plants per foot, there is minimal benefit to increasing the population.

On a final note, we tend to get in a rush this time of year and sometimes that can set us back. A friend of mine once told me, “There is never enough time to do it right but there is always enough time to do it over.” We should all keep that in mind when we make a decision and implement a practice, especially when we feel rushed.

Taking A ‘Pegging Zone’ Test?

Scott Monfort

Scott Monfort
University of Georgia

The peanut crop is off to a good start in Georgia with most of the crop planted, emerged and growing. One thing growers need to keep in mind is calcium. Growers do not want to get to the end of the season and learn about a calcium deficiency.

The most noted symptom of calcium deficiency in peanut is underdeveloped kernels in the pod better known as “pops.” Glen Harris, UGA soil fertility specialist, recommends supplemental calcium based on the following conditions: 1. When soil test for Ca is less than 500 pounds per acre (Mehlich 1 extraction), 2. When the Ca:K ratio is less than 3:1 (i.e. at least three times as much Ca as K), and/or 3. When peanuts are grown for seed. Calcium on seed peanuts is important because a lack of calcium can cause poor germination.

How does a grower determine the calcium level in a select field once peanuts are planted? If a soil sample was not taken in the spring and you are unsure of your calcium levels in the soil, a “pegging zone” sample is the easiest way to determine if a select field has adequate calcium for pod development. The pegging zone sample is taken just like a regular soil sample but only at the depth of three inches. Taking the sample no more than three inches ensures growers get an adequate measurement of calcium in the pegging zone only. One thing to remember – pegging zone samples need to be taken as soon after emergence as possible in order to get the results back and the calcium applied by the time the plants initiate blooming. Please contact your county Extension agent for more information.