Planting Speed Comparison

Adequate stands can mean the difference between great yields and average yields. Last year, seed quality and weather played a role in skippy stands resulting in greater tomato spotted wilt virus and decreased yield in some fields. Based on the quality of the 2017 peanut crop, hopefully skippy stands because of poor germination and/or low vigor seed will be minimal. Follow the weather to make sure you are not planting in cool, wet conditions that might increase seedling loss.

After talking to many growers, I found out that some stand issues were from planting too fast. The picture shows a University of Georgia variety trial (right) planted next to a grower field. The UGA trial was planted at 2.5 miles per hour. The grower planted at 4.5 miles per hour. One of the main impacts of the skippy stand was a 15 percent increase in TSWV.

This impact in tractor/planting speed has also been documented in research conducted by Scott Tubbs, UGA cropping systems agronomist. The tractor/planting speed research showed the faster the planter moves through the field, the more skips that occur and reduces plant stand. In comparing tractor speeds of 2 to 4 miles per hour, the data showed a 15 to 17 percent improvement in plant stand and a statistical improvement in yield using the slower speed.

While it is unrealistic to expect growers to cover the ground they need to cover while traveling that slowly, the take-home message is that the slower you travel at planting, the closer your plant stand will be to your targeted seeding rate.

A grower may decide the answer to this problem would be to increase seeding rate to compensate, but it depends on your planter. Tubbs mentioned that simply gearing the planter for an increased seeding rate does not mean that more seed are going to be dropped in the furrow. The seed plate would be spinning at an even greater rate and may cause even more skips.

The tractor speed still needs to be at an appropriate operating level for the planter to function correctly and eliminate an unacceptable level of skips.

With that said, many of the new hydraulic and electric driven planter units can do a better job at planting at higher speeds but are not immune to similar problems with speed and stand establishment. The cost of time from slowing down a little will pale in comparison to the cost of time, and other expenses, of having to replant. Call your Extension agent if you need any assistance.[divider]

Do What It Takes To Start Clean

Many of you are making final plans on field selection and tillage for the coming season. Keep in mind the value of rotation sequence and the importance of a clean seedbed when peanuts begin to emerge, either from adequate and uniform tillage or an effective burndown program or both. I say both because in wet springs, fields may be tilled only to wind up covered in weeds because of planting delays.

There are also circumstances in which winter vegetation and emerged summer weeds are big because of delays in initial tillage operations because of excessive rain. Tilling several times in a narrow window can result in big weeds simply being covered up with soil. Amazingly, these big weeds “resurrect” from the tilled ground. This is when the conventional farmer becomes a reduced-tillage farmer.

One effective herbicide spray several days or a week before the primary tillage operation can substitute well for a pass or two with a disk. It is important to do everything it takes to start clean!

On another topic, in the Integrated Pest Management class I teach, we discuss the economic injury level and economic thresholds (EIL/ET). We often think of these with respect to insect populations and making sound economic decisions on treating. But the concept can be applied to other pests. In May, it is critical that we manage weeds and thrips because both pests can limit yield if not controlled.

We know from previous field history (weeds) and from growing peanuts or cotton in the region (thrips) that in most instances these pests will be above the EIL during the first 3 weeks of the season if we don’t apply herbicides and an insecticide. In North Carolina, we can safely assume that preplant and preemergence herbicides and a systemic insecticide applied in the seed furrow at planting are good economic investments and will pay dividends well above their costs. We correctly make this decision even though we have not gone through the exercise of calculating the EIL.

Of course, we could treat after the peanuts are up and the pests or damage appear, but in most instances we will be making later applications than needed to provide protection of yield. Similarly, we know that soil pathogens will prevent us from obtaining an adequate stand in the V-C region unless seed is treated with fungicide. The first 3 weeks of the season set the stage for success – a good stand of peanuts that is protected from interference by weeds and injury from thrips is well on its way to meet our expectations.[divider]

Reasons For Inoculant Use

A major benefit of incorporating peanut into a crop rotation is that it responds well to residual soil fertility. For this reason, fertilization practices for the previous crop are extremely important. Residual nutrients must be available uniformly throughout the root zone. Soil test results will indicate which nutrients need to be applied to meet the yield goal for this coming season.

Applications of fertilizers should be made before land is prepared for planting. Primary tillage operations will distribute the fertilizer throughout the root zone. Starter or pop-up fertilizers may be an option. However, it is important to use appropriate rates. Placement is also critical as germinating peanut seed are extremely sensitive to salt damage.

Peanut plants are capable of utilizing nitrogen from nitrogen-fixing bacteria (Rhizobium spp.) in the soil. These bacteria are what comprise peanut inoculants that are available in granular or liquid formulations, which are applied to the seed furrow at planting. Following effective inoculation, nodules form on the taproot compared to nodules that occur on lateral roots resulting from native Rhizobium spp. or bacteria from previous peanut crops.

Survival of these bacteria is effected by the duration of crop rotation and soil conditions. The bacteria are unable to survive long periods without peanuts being planted, as populations are specific to peanut. Furthermore, the hot, dry conditions that were experienced throughout the late fall and winter may also impact survival in the soil. Thus, it is recommended that inoculants be used when planting peanuts in West Texas.

Several types of peanut-specific inoculants are commercially available. Shallow planting depth, even in moist soil, can greatly reduce the efficacy of inoculants. Liquid inoculants are currently the most popular and achieve high levels of nodulation, but granular inoculants may be more effective under harsh, dry conditions. Contact your Extension office for more information regarding peanut inoculants.[divider]

Early Insecticide Use

It is almost peanut planting time. Many growers have talked with me about planting earlier this year, and this is fine if conditions such as soil and air temperature are favorable. One difference in planting earlier is the use of an insecticide. Some producers planting later in the season haven’t been using anything for thrips, which I don’t disagree with when planting late.

However, when planting early, I would recommend using some type of insecticide for thrips whether it is phorate, aldicarb or imidacloprid in-furrow. Thrips pressure is usually the greatest early in the season. Therefore you need some protection during that high-pressure period for young plants to get kicked off to a good start.

I also recommend adding a fungicide if you’re setup for liquid in furrow. The past few seasons have given us some significant yield benefits from in-furrow fungicide treatments. Is there more disease pressure with wet, cool or hot, dry conditions? The answer is both. If the soils are cooler and wetter, the risk of seedling disease caused by Rhizoctonia solani increases. In soils that are hot and dry, the risk of Aspergillus crown rot and Diplodia collar rot increases. I hope this planting season finds you with adequate soil moisture and a great start for the 2018 peanut season.