V-C News

— Written By

With this article I plan to make summary comments from our 2014 research project. We always provide a technical report, but with this column I would like to provide comments that might be considered more user-friendly. This research was funded by peanut growers and we at NCSU appreciate your support.

Objective 1. To develop solutions to agronomic issues associated with peanut production in North Carolina. 

Inoculate every acre! No matter what! In new ground, the average yield increase is about 1400 pounds/acre over non-inoculated peanut. In rotated ground a more moderate but significant increase of 200 pounds/acre can be expected. But with new ground, make sure that you do everything possible to minimize a mistake with inoculant. Proper placement, handling, storage, mixing and other factors can influence inoculant performance. If some type of mistake was made and you have a true nitrogen deficiency, apply 500 pounds of ammonium sulfate just as soon as you can. See the section in our 2015 Peanut Information series for more discussion on the topic of inoculation.

Virginia market type peanut have a range of maturity levels. Work in 2014 suggests that Wynne will mature later than Bailey, Sugg or Sullivan. Runner market types do perform well in North Carolina. Going into 2015, if you plan to grow peanuts, especially if you have a substantial increase, make sure you have a home for them. There are storage costs and other issues you need to consider. Runners will be a less expensive option than Virginia market types, primarily from the expense of gypsum and seeding rates. However, the margin is smaller than it used to be, especially when we were comparing Gregory or Perry to the runner type Georgia Green compared with the Virginia and runner varieties currently being grown. With jumbo runners in the mix, and given Bailey seed is relatively small, seeding rates are closer between the market types and the need for gypsum is higher for the runners. We suggest at least half of the Virginia rate for gypsum and when you look at jumbo runners and Bailey, the amount of seed needed to establish the same plant population differs by about 20 pounds.

Historically, Apogee has not only increased row visibility but also yield. With Bailey, many of our trials have shown no difference in yield when treated with Apogee compared with non-treated peanut. For example, this past year we conducted 9 trials with Apogee. In only one of those trials did we see a yield increase and that was with peanut planted on 30 inch rows in a grower’s field. However, the yield increase was substantial, well over 500 pounds/acre was obtained when Apogee was applied. While I have often recommended 2 applications for the best results, in many of these trials a single application would have helped on row visibility. Not at every location but at many of them. Bailey seems to hold pods on quite well, and we have most often attributed yield increases from Apogee as a result of improved pod retention and less pod shed during digging. Apogee, like mepiquat chloride in cotton, is providing growers with more effective management of the crop even when we don’t always see direct impacts on yield from our small-plot research. A substantial number of growers are applying Apogee (see table).

Objective 2. To cooperate with the plant pathologist, entomologist, and plant breeder at NCSU to refine IPM strategies for peanut in North Carolina. 

We have excellent scientist and extension specialists at NCSU in the areas of plant pathology, entomology, breeding and engineering. We all work closely together on key aspects of production and pest management. Rick and I have worked closely for the past few years on thrips management, and we have good data sets on thrips control, tomato spotted wilt virus and yield with seed treatments, in-furrow granular or liquid products, and foliar sprays. Thimet and Admire Pro, and to a lesser extent acephate, have filled the void in absence of Temik. While all in-furrow insecticides may require follow-up with a foliar spray, reliance on seed treatment for thrips control will definitely require a well-timed acephate spray. One big question we have had is compatibility with imidacloprid with inoculant. Our work shows that these products are compatible.

Objective 3. To conduct appropriate research to develop weed management strategies for traditional and herbicide resistant weeds in peanut in North Carolina. 

Each year we conduct numerous weed management trials at both Lewiston-Woodville and Rocky Mount stations. The weed complexes differ but we are able to get a good feel for how herbicides will perform. This past year we evaluated Brake F2, Fierce and Zidua. These products may or may not make it into the peanut market, and none of these are standalone materials. Recently, Warrant received a registration for soil-applied and postemergence applications in peanut. Certainly Warrant is not a standalone product either but it does bring help on pigweeds to the table. We have several sections in the 2015 Peanut Information series that can help you in deciding what herbicides to use. Just be timely with whatever you spray!

Objective 4. To continue rotation and tillage trials in order to develop more effective cropping systems. 

Growers want as much information and as much flexibility in their rotations as possible in order to take advantage of marketing opportunities. We have had rotation or cropping system trials in place since the late 1990s. Barbara discussed results from those trials last year with respect to nematodes. Currently we have moved into another cycle so it will be a few years before we have a great deal to talk about in terms of these trials. We’ve learned, and I think this backs up what some growers already know, that sweet potato is a good rotation for peanut. We have also found that sage and peanuts need to be separated by a year with corn, cotton or grain sorghum in between to protect peanut yield. With the increase in grain sorghum acreage, we have seen peanut response for this crop and corn or cotton is generally the same when it comes to peanuts. Most of our data shows that yields in strip till and conventional tillage are similar for peanuts and that previous rotation does not impact peanut response to tillage. However, 2013 and 2014 were relatively wet years and we tended to see lower yields in strip till than in conventional tillage. I suspect drainage had something to do with this response, and in dry years we have seen strip-tilled peanut outperform conventional tillage.

Objective 5. To determine the feasibility of double-cropping peanut and other crops with wheat. 

While double cropping peanut or cotton and perhaps corn behind wheat seems implausible, this could change based on crop price. In 2014 we completed the second year of a three year study comparing crop yield with two normal planting dates of corn, cotton, grain sorghum, peanut and soybean with plantings after wheat harvest. I’m still crunching some of the numbers, but peanut yields were about the same with early May and late May plantings, and both of these yields exceeded those of the double crop planting by over 15%. The key will be looking at the yields, inputs and income at various pricing structures.

Objective 6. Assisting Cooperative Extension agents with pod maturity clinics. 

Dewayne Johnson, the technician in the peanut agronomy program, assisted many Cooperative Extension Service agents with pod maturity clinics in their counties, especially county agents with limited experience with this process. Dewayne participated in about 15 maturity clinics and processed approximately 300 samples. He also made numerous contacts visits with individual farmers. It is estimated that Dewayne helped make recommendations for about 20,000 acres in the process, or about 25% of the acreage in North Carolina. Although economic calculations on the benefit of his input are challenging to capture, his assistance may have contributed to farmers generating over 1 million dollars due to timely digging. We are a long way off from digging the 2015 crop, but doing a good job here can make a tremendous difference in profit.

In spring and summer issues I’ll go into more specifics for the time period. But in the meantime, thanks again for supporting our programs at NCSU!

Table 1. 2014 Virginia and North Carolina Peanut Production Survey 

157 farmers representing 34,211 acres (Data are presented as the percentage of total acreage)
Percentage of your acreage treated with Apogee
Percent of acres 30
Practices you used to manage CBR (back root rot) 
Fumigate 15
Proline in-furrow 30
Rotation 86
Variety selection 82
Practices used to manage thrips when you planted peanuts
Thimet 35
Cruiser Maxx 18
Orthene 54*
Admire Pro 21
Temik 1
*this could be an overestimate given growers might not have distinguished between in-furrow and foliar sprays
Acreage treated with Orthene after peanuts emerged
Percent of acres 66

Article first appeared as North Carolina Peanut Note (PNNC-2014-147)