Duration: 10/01/2023 to 09/30/2028

Administrative Advisor(s):

NIFA Reps:

Non-Technical Summary

Statement of Issues and Justification

Created in 1968, the Multistate Hatch S-1079, S-1059, S-1038, S-1003, S-140 [known as the Peanut Variety and Quality Evaluation (PVQE)] has provided variety testing for over 50 years. This Multistate has been recognized as a strong data support program for the virginia-type (market types are lowercase by convention) cultivar development. The project also provided a forum for various segments of the peanut production, shelling, and processing industries to express the industry’s emerging needs through the annual meetings of the PVQE Advisory Committee.  Virginia-type peanut (Arachis hypogaea L. subsp. hypogaea var. hypogaea) is distinct from other peanut market types, i.e., runner, spanish and valencia. This distinction is from the seed and pod size, which are larger for virginia than for other types. For example, pod count is less than 318 kg^-1 when sized on 15.9-mm by 76.2-mm screen, and seed is an average of 1055 kg^-1 for virginia type when compared with 477 kg^-1 and 1830 kg^-1, respectively, for the other peanut types. Indeed, the virginia-type peanuts are almost twice the weight of the other types, and have high content of extra-large kernels (ELK), i.e. seed not passing a 25.4-mm by 8.5-mm screen, for which farmers receive premiums.  For an average return of $355 ton^-1 of farmer stock peanut, approximately $20 ton^-1 is from the ELK content. 

Significance of the Virginia-type peanut in U.S. peanut production: Virginia-type peanut is grown in Virginia and the Carolinas (VC) as well as the Southwest (SW). In the VC region, peanut is an important cash crop with annual acreages ranging from 175,000 to 230,000 ac. For example, in 2021, total peanut production of this region was 457 × 10³ tons, with a $215 million value from 210,000 harvested acres (USDA-NASS, 2022). From this, 80% is attributable to virginia-type cultivars. Gourmet processing trade sets this region, and Virginia in particular, apart from the other peanut growing states since the majority of these firms are located in Virginia. For this market, it is the largest of the ELK that carry the highest value of the virginia-type peanut, called Super ELK (SELK), i.e. seed not passing a 25.4-mm by 9.6-mm screen. In the SW, virginia-type is grown in Texas and Oklahoma on acres ranging from 20 to 45% of the total certified peanut acreage (Chamberlin et al., 2019, 2022). For example, in 2020, Texas planted 47,232 acres of virginia-type of the total 221,746 production acres (survey conducted by the Texas Peanut Producers Board and Bob Whitney, 2022). In these states, a large portion of the virginia-type peanut is exported. For these markets, pod and seed size, i.e. high content of ELK, and pod color (i.e. pod brightness at least 45 based on Hunter L. score) are important (Chamberlin et al., 2019). For decades, PVQE provided, in addition to yield, information on pod and seed size and quality, i.e. farmer stock grade, and financial return was estimated from yield and grade for each tested line. Pod color has been also measured and, along with yield, grade and economic return, this information was annually published within the PVQE Agronomic and Grade Data reports (Balota et al. 2022a).

The need to maintain quantity and quality: Since the early years of the Multistate, estimated dollar returns to the grower increased from $600 per acre in late 80’ s and 90’ s to $850 per acre with the release of Bailey II in 2019 in the VC region. Because the dollar return is calculated from a complex USDA formula using yield and grade characteristics, this is an indication that both yield and grade are important to consider for further improvement of virginia-type peanut production.  For example, average yield of the cultivars released after being tested in the PVQE Multistate went from 4,000 pounds per acre for cultivars released in early 90’ s to 6,000 pound per acre for the recent releases. Similarly, ELK content of NC-V 11, released in 1991, was 34.2% while that of Bailey II was 47.7%.

Both regions grow virginia-type cultivars with over 74% content of oleic fatty acid (C18:1), or “high oleic” cultivars. The high oleic oil chemistry, i.e. increased C18:1 and decreased linoleic (C18:2) fatty acid content, improves peanut shelf life, reduces rancidity, and increases safety for consumers.  Earlier research showed that high oleic peanut has improved oxidative stability and longer shelf life than non-high oleic peanut.  For example, roasted in shell peanuts with 50% C18:1 reached a Peroxide Value (PV) of 20 meq kg^-1 (as indication of oxidation) after only 2 wks. of storage.  However, peanuts with 80% oleic fatty acid did not reach 20 meq kg^-1 until after 40 wks. of storage (Mozingo et al., 2004).  Since the deployment of S-1059, all lines tested in the PVQE have been high oleic. Recently released cultivars after being tested in the PVQE, i.e. ‘N.C. 21’, ‘N.C. 20’, ‘Walton’, ‘Bailey II’, ‘Emery’, ‘Sullivan’ and ‘Wynne’, are also high oleic. Blanchability is the seed capacity to maintain intact after testa has been removed and represents an important characteristic in peanut processing. Information on oil profile and blanchability was annually included for each breeding line within the PVQE Quality Data reports (Balota et al. 2022b).

The need to improve sustainability: Drought significantly limits peanut production in the VC and SW.  In the SW, the Ogallala aquifer (the only source of irrigation) is declining at a rate of 0.3 m per year, which will cause depletion within the next 30-40 years (Paxton Payton, personal communication, 2019). This decline is already reducing the ability to irrigate at critical growth stages and when temperature exceeds 40 °C. Similarly, in the VC region, precipitation distribution is irregular and often deficient during the summer months.  Concurring with increasingly higher summer temperatures, this leads to frequent droughts which may affect peanut yield, grade, C18:1 content, and economic return in otherwise “rainy” years (Balota et al., 2015; Ramsey et al., 2020; Singh et al., 2014).  In particular, ELK and SELK require ample amounts of water to fill the seeds. Supplementing water through irrigation is an option, but only 10% of the peanut land is irrigated in the VC region.

Additionally, adjusting planting time to avoid drought can enhance the impacts of periodic extreme temperatures at critical flowering times. Therefore, improving peanut yield and quality during drought and extreme temperature episodes in rainfed production is now a priority for peanut production in the U.S.  

Within previous years of uniform cultivar trials, we have identified and released three breeding lines and cultivar ‘Walton’ expressing drought tolerance, i.e., relatively high yields under drought (Balota et al., 2021; Balota & Isleib, 2020; Balota et al., 2015; Tallury et al., 2014). Since deployment of S-1079 and leveraging PVQE efforts with a collaborative project with North Carolina State University (NCSU) (USDA NIFA AWARD # 2016-08666), we have identified several genomic regions and markers associated with drought tolerance traits in peanut (Kumar 2022) and are poised to complete similar work with heat stress tolerance traits. Through collaborative work with Texas A&M University, Oklahoma State University, and USDA-ARS we also leveraged efforts to develop high-throughput methods to phenotype drought and heat stress tolerance (NIFA-AFRI grant no.- 2017-67013-26193) (Sarkar, 2020). Within the current S-1079, we implemented rainout shelter testing for selection of peanut lines tolerant to heat and drought, but this method only allows for testing a limited number of lines at one location. Therefore, moving efforts towards use of “smart” technologies, as proposed in the multi-disciplinary and collaborative effort with Clemson University, NCSU, and Virginia Tech (NIFA-AFRI grant no.-2023-67013-39624) is the next logical step we propose during 2023 – 2028 stage of the project.

The need to exploit genetic and physiological mechanisms: Global increases in temperature and drought are major threats to crop production globally (Lesk et al., 2021). A combination of drought and heat stress can impact a number of physiological processes important in plant development and reproduction. In particular, sub-lethal elevated temperatures can directly impact yield by affecting the timing and production of flowers as well the viability of pollen (Paupiere et al., 2014) and these impacts can be compounded when coupled with drought (Prasad et. Al, 2008). Unraveling the genetic and physiological mechanisms that govern plant responses to these environmental stressors is central to developing crops that are climate adapted or resilient. This is a pressing problem in climate sensitive crops like peanut, where subtle shifts in temperature are threating global production (Ramsey et al., 2022). Yet, improving peanut yield and quality during periodic temperature elevation and drought stress has been identified to be of critical importance for the peanut stakeholders in the USA to maintain their competitiveness in the marketplace. The magnitude of change in the warmest periodic 5-day 1 in 10-year heat event is projected to be ca. 6^°C (U.S. Climate Info 2017). This increase early in pollen development has been shown to have significant impacts on yield in peanut and other legume crops, even over short durations (Prasad et al., 1999). Coupled with late season drought—the most important yield and quality limiting factor in peanut production worldwide (Songsri et al., 2008)—peanut and other crops face constraints during early flowering from heat stress and during pod filling from drought (Prasad et. al, 2008).

While this is true for the major peanut growing regions in the US, it is particularly true for peanut grown in the VC region. The predominant type of peanut grown here is the large seeded virginia-type or “gourmet” (market types are lowercase by convention). Virginia market-type peanut has the largest seed size among all the peanut types grown in the USA, where a kilogram of “gourmet” peanut has about 1000 seeds and runner peanut has about 1900 seeds. Whether larger seed require more water for full development than smaller seed is not known; but it has been shown that spanish types known for their small seed size are more drought tolerant than virginia type peanut (Erickson and Ketring, 1985). Prasad et al., (1999) found that these two types are also prone to pollen declines under heat stress during early flowering. This timing is critical because it means that growers cannot overcome these two stressors with a simple shift in planting time. Historically the VC region has been classified as “sub-humid,” and little attention was paid to short-term drought episodes that can impact seed yield and quality. This oversight is particularly troublesome because the soils of this region are sandy resulting in rapid soil water depletion, which is exacerbated by recurrent intervals of low rainfall and periodic extreme heat events. In the VC region, 85% of peanut is rainfed, but drought stress-related research has been almost absent. Preliminary research determined that uneven rainfall distribution and summer heat events in the VC region can significantly limit peanut yield and production value up to $15,000,000 in otherwise “good rainy” years (Balota et al., 2016). Under these conditions, the most reliable solution for peanut producers to mitigate heat stress and combined heat and drought stress is to adopt tolerant cultivars.

Related, Current and Previous Work

High oleic virginia-type cultivars have been developed by the breeding programs in the VC, Southeastern (SE), and Southwestern U.S. (Balota et al., 2021; Branch e al., 2020; Chamberlin et al., 2019, 2022; Dunne et al., 2022; Isleib et al., 2006a; Barry Tillman, personal communication, 2012). Cultivars and germplasm released after being tested in the PVQE Multistate in the VC region include ‘N.C. 21’ (Jeff Dunne, personal communication, 2022), ‘N.C. 20’ (Dunne et al., 2022), ‘Walton’ (Balota et al., 2021), ‘GP-VT NC 01’ (Balota & Isleib, 2020), ‘Bailey II’ (Isleib, 2017 unpublished), ‘Sugg’ (Isleib et al. 2015), ‘Emery’ (Isleib, 2015 unpublished), ‘GP-NC WS 17’ (Tallury et al., 2014), ‘Sullivan’ (Isleib, 2013 unpublished), ‘Wynne’ (Isleib, 2013 unpublished), ‘Bailey’ (Isleib et al., 2011), ‘Titan’ (Balota et al., 2011), ‘CHAMPS’ (Mozingo et al., 2006), ‘Brantley’ (Isleib et al., 2006 a), ‘Phillips’ (Isleib et al., 2006 b), ‘Wilson’ (Mozingo et al., 2004), ‘Perry’ (Isleib et al., 2003), ‘VA 98R’ (Mozingo et al., 2000), ‘Gregory’ (Isleib et al., 1999), ‘NC 12C’ (Isleib et al., 1997), ‘VA 93B’ (Coffelt et al., 1994), ‘VA C92R’ (Mozingo et al., 1994), ‘NC 10C’ (Wynne et al. 1991 a), ‘NC V 11’ (Wynne et al., 1991 b), ‘NC 9’ (Wynne et al., 1986); ‘NC-8C’ (Wynne & Beute, 1983), ‘VA 81B (Coffelt et al., 1982), ‘NC 7’ (Wynne et al., 1979), ‘NC 6’ (Campbell et al., 1977), ‘NC Fla’ (Emery et al., 1974), ‘VA 72R (Alexandre & Mozingo, 1972), and NC 17 (Emery, 1970). These cultivars were developed and released by Virginia Tech, USDA-ARS and NCSU individually and collaboratively among these universities or with other universities [such as the University of Florida (UF)].

Several PVQE releases originally developed for the VC region are now being grown in other regions and/or used as parental lines in crosses. For example, in 2020, Texas planted 16,816 acres of Wynne, 5,262 of Sullivan, 4,908 of Emery, 817 of Baily, and 227 of Bailey II. This is a total of 28,388 acres, which equals the total peanut acreage grown in Virginia, in 2020. On the same note, Brantley peanut, tested in the PVQE and released for the VC region, has been used as a parent for development of cultivar ‘Contender’ in Oklahoma (Chamberlin et al., 2019). Similarly, ‘Comrade’, developed in the VC region, has been released in Oklahoma in 2022 jointly by the USDA-ARS and NCSU (Chamberlin et al., 2022). This was possible through collaboration aimed to intensify screening for earliness, disease resistance, and enhanced pod size distribution of VC germplasm.

Growers in Florida do not grow virginia-type peanut. However, the breeding program at the University of Florida maintains virginia-type breeding lines with unique grade characteristics. One of the characteristics is the high percent of SELK kernels, e.g. almost double than the SELK of the NSCU lines (Balota et al., 2022c), that have high value in the VC region. To use that characteristic, a collaboration between University of Florida and Virginia Tech was facilitated in 2012. As part of this collaboration, F4 lines started from crosses in Florida are being sent to Virginia for advancement to F7 and agronomic testing across multiple locations. Cultivars are jointly released by the two universities; from this collaboration ‘Walton’ was released in 2019. While the majority of the current virginia-type cultivars were developed and tested in the VC region, more effort is now needed to exploit all existing resources, i.e. “hot spot” locations, expertise, germplasm, etc., through collaborative efforts. This project is aimed at facilitating the exchange of resources across the virginia-type peanut breeding programs in the USA.

Agronomic and pest management information in the VC region has primarily targeted the virginia-type peanut, the predominant peanut market type grown in this region. However, agronomic trials including virginia-type cultivars are being conducted in SE and SW.  For example, in Texas, there is an interest in elucidating the effect of seeding rate on yield for runner and virginia-types. Interestingly, their 2010 report shows that while there was a clear yield increase for the runner cultivars with increasing the seeding rate from 1 to 6 seeds per foot, for the virginia-type cultivars there was no relationship  RPVT 2010.xlsx (agrilife.org). This result coincides with results by Oakes et al. (2020) in the VC region and has important implications for growers. Explicitly, large size of the virginia-type peanut requires large quantity of certified seed for planting, for which the planting costs are high; the higher the seeding rate per foot the higher the cost per acre. If less seed can be planted with no effect on yield and financial return, the planting expenses will be less. In Oklahoma, agronomic and disease evaluations of all peanut market types are conducted annually. In 2022, for example, disease testing included 12 virginia-type cultivars and lines, from which two were lines from the NCSU (Disease Evaluations and Agronomic Traits of Advanced Peanut Breeding Lines in 2022 | Oklahoma State University (okstate.edu)). In addition to the VC, variety trials including virginia-type cultivars and lines are being conducted annually in both, Texas and Oklahoma (2022-Peanut-Variety-Trials-Breeding-Lines.pdf (agrilife.org); 2022 Oklahoma Peanut Variety Trials | Oklahoma State University (okstate.edu)). Information generated across entire U.S. peanut belt can help development of more sustainable virginia-type cultivars for the country, and this project is aimed at facilitating increased collaboration and communication to achieve this goal.

Objectives

1. Deliver new and improved cultivars including researchers at multiple breeding programs that develop virginia-type peanut.
   
2. Promote best agronomic practices through concurrent trials conducted in multiple states and locations.
   
3. Demonstrate effectiveness of current and novel pest management control systems across the virginia-type peanut production belt.
   
4. Exploit the genetic and physiological bases for adaptation to climate change to improve peanut cultivar development.
   
5. Expand the use of “smart” technologies in precision breeding and management of virginia-type peanut.
   

Methods

Objective 1: Deliver new and improved virginia-type cultivars through breeding and variety testing.

Under this objective, our major goal is development and variety testing for improved yield, quality, and other specific priorities of each region (VC, SW, and SE), collaboratively. Examples of research projects currently under development are included below, but we envision additional projects to promote development of virginia-type cultivars throughout the USA peanut belt.

Breeding for Early Maturity

Seed maturity determines economic return to producers because of its impact on yield and other seed quality characteristics determined at buying points across the United States. Early maturity is an important trait across the USA peanut belt, but mostly for the VC region because the VC is the northernmost peanut grown region. Therefore, we envision that this task will be a priority for the VC region in particular.

Breeding for Optimum Maturity

During seed development, the mesocarp layer of the peanut hull (pericarp) transitions in color from white (immature) to black (mature), correlating to increased seed weight and size, respectively. Furthermore, peanuts are semi-indeterminate plants, meaning they continue to flower, peg and produce pods over an extended window during the growing season, subsequently creating a wide range in seed maturity at the time of harvest. Optimum maturity is the point where a majority of the pods sampled across a production farm reach maturity (mainly brown-black hulls), where the yield and seed quality peak, maximizing grower profits. The current method for determining optimum maturity involves pod blasting, the manual removal of the exocarp revealing the inner mesocarp layer, prior to peanut digging and harvesting. The difficulty in evaluating yield/optimum maturity and subsequently seed quality (grade) performance relative to >100 advanced breeding lines tested annually in a peanut breeding program testing network is that each line has a different optimum maturity and ideally would need to be dug at different times for more accurate comparisons. Because this is nearly impossible to perform due to intense labor requirements, estimating relative maturity and the offset on yield based on early or late digging can help adjust yield values based on predicted performance as determined by seed maturity. Each year, the decision to dig advanced yield trial plots is based primarily on the optimum maturity of a single variety grown extensively in the VC region (i.e. Bailey II), which the program considers to be the new regional standard. Since grading samples (pod and seed quality) are already collected on small plot increases or advanced yield trials, additionally pod blasting each sample prior to shelling the samples for seed quality evaluations can help determine relative maturity in comparison to regional standard. The yields can then be offset/adjusted based on optimum maturity performance, improving selection efficiency towards future cultivar releases with improved yields and grade quality. In addition, pairing genomic information with the adjusted optimum maturity evaluations can further improve selection efficiency and accuracy through the identification genomic regions that determine seed maturity. The identified quantitative trait loci (QTL) can be implemented through predicted performance on a genome-wide basis. Having the ability to integrate molecular tools to select for early instead of later maturity or narrow instead of broad indeterminant maturity windows can improve the sustainability and profit margins for growers by avoiding late season disease pressure or improve profitability through enhanced peak optimum maturity and seed quality, respectively. An emphasis will be placed on selecting lines with similar or improved agronomic performance to check cultivars, but displaying earlier maturity.

Validation of Breeding Program Selections for Early Maturity in the VC region

To validate the adjusted optimum maturities coming from breeding programs focused in the VC region, replicated experimental tests will be conducted at multiple locations in Virginia (one location), North Carolina (three locations), and South Carolina (one location), each with two digging dates; early (~140 DAP) and late (~155 DAP). The purpose of the two digging dates will be to provide producers in the region with projected optimum maturity prior to release. For each of the locations, selected virginia-type breeding lines will be compared to the current, high oleic cultivars grown in the region (i.e. Bailey II, Emery, NC 20, NC 21, Sullivan and Walton). Each entry will be evaluated for yield, pod and seed grade quality, maturity and roast flavor. For the trials themselves, all breeding lines tested will be planted at each location using a precision planter in rows spaced 36-inches at a seeding rate of 4-5 seeds per foot row. Plots will be 105 sq. ft. (35 ft long) and replicated four times for each of the digging dates proposed. Plots will be planted, maintained, and harvested similarly across each growing environment (location) including planting timing, pesticide application and timing, and harvesting dates in accordance to extension recommendations and to promote uniformity across the PVQE trial. Each plot will be harvested into bags and dried to a uniform moisture content prior to taking a yield weight. From each harvested bag, a grade sample of approximately ~1,200 grams will be taken for pod and seed grade evaluations and flavor panel assessment of sensory quality. All data will be evaluated/analyzed based on the experimental design for each location and presented at the annual PVQE Advisory Committee Meetings and other Virginia-Carolina related grower’s meetings prior. In order to be considered for release, a breeding line will be entered into the PVQE for three years.  Successful development of improved cultivars by the breeding programs heavily relays on the genetic diversity of the germplasm used in crosses. In the case of virginia-type peanut, joint release of cultivars creates opportunities for increase of diversity. For example, ‘Comrade’ was jointly released by USDA-ARS and NCSU (Chamberlin et al., 2022), ‘Walton’ was released by UF and Virginia Tech (Balota et al., 2021), and ‘Contender’ was developed from a cross with a line developed in the VC region and tested in the PVQE Multistate (Chamberlin et al., 2019). For Virginia in particular, the SELK content is an important grade characteristic. This is the largest of the ELK that carry the highest value of any of the virginia-type kernels for the shelled goods. These kernels (SELK) provide the backbone for the gourmet processing trade, which sets Virginia apart from all other peanut growing states (Dell Cotton, personal communication). To address the need for cultivars with high percent of SELK, ‘Titan’ was released in 2011 after being tested under S 1079 Multistate (Balota et al., 2011). However, this cultivar was not ‘high oleic’, a characteristic that became a standard for the peanut industry after 2011. Further, a collaboration with UF identified ‘high oleic’ peanut lines with high SELK content (Balota et al., 2022c) and with high yield under dry environmental conditions (Balota et al., 2021) when grown in Virginia. Situated farthest north within the VC region, Virginia has 90 to 300 ºC less summer heat units than South Carolina for which requires early maturing cultivars. Therefore, cultivars developed in SE or SW can be grown in Virginia if, in addition to high yield, disease resistance and abiotic stress tolerance, they are early maturing and with high SELK content. Previous research has demonstrated that breeding lines developed by UF are productive in the VC region, resistant to the late leaf spot disease [caused by Nothopassalora personata (Berk. & M.A. Curtis) S.A. Khan & M. Kamal (syn. Cercosporidium personatum [Berk. & M.A. Curtis] Deighton)], drought tolerant, and have high percent of SELK (Balota et al., 2021; Balota et al., 2022c).

Breeding for high content of SELK

Research will be conducted at multiple locations in Virginia, on- and off station in farmer fields, to evaluate the agronomic characteristics of the UF breeding lines in comparison with the current commercial cultivars. The lines comparable or exceeding the check cultivars will be included in PVQE testing in the VC, and in other variety trials in SE and SW regions. Finally, successful lines for one or multiple agronomic characteristics of multi-year and multi-location replicated trials will be released as cultivars.

Thrips Challenge of Cultivars and Lines

Each year, new F4 or F5 breeding lines will be provided by collaborator at the UF. Along with check cultivars Bailey II, Emery, NC-20, NC-21, and Walton, the lines will be grown in replicated small plot trials at the Tidewater AREC, with and without in-furrow applications for thrips (Frankliniella fusca and F. occidentalis) control. Thrips damage, Tomato spotted wilt virus (genus Tospovirus; family Bunyaviridae) (TSWV), and white mold disease [caused by Athelia rolsfii (Sacc.)] pressure will be recorded during vegetation. At the physiological maturity, yield and market grade characteristics will be determined. Lines with high yield and grade characteristics, and disease resistance will be moved to the next level of testing as described below; the other lines will be discarded.

VT/UF Yield and Quality of Cultivars and Lines

Selected lines from the “Thrips Challenge” testing, along with check cultivars Bailey II, Emery, NC-20, NC-21, and Walton will be grown on- and off-station in replicated agronomic trials at multiple location in Virginia. In farmer fields, planting and crop maintenance will be performed by the collaborating grower using their particular soil preparation, i.e. conventional till, strip-till or no-till, and cultural practices. During vegetation, data on disease, thrips and other insect pests, and crop stand will be collected. At the physiological maturity, yield and market grade characteristics will be determined. Lines with high yield and grade characteristics, and disease resistance will be retained for additional 2 years of testing and Virginia, moved to the PVQE testing; the other lines will be discarded.

Variety testing of virginia-type peanut

This objective will include variety development and testing in all peanut production regions interested in development and/or production of virginia-type peanut. This can include, but not limited to, The Uniform Peanut Performance Tests (UPPT), and variety testing in Oklahoma and Texas. Collaboration conditions will be determined by the participants in accordance with the State, University and Program regulations.

Objective 2: Promote best agronomic practices through concurrent trials conducted in multiple states and locations.

Numerous cultural practices can affect peanut yield either by promoting overall health and nutrition of peanut or by suppressing pest populations in the VC region of the US where virginia-market type cultivars are popular (Jordan et al., 2020a, 2022, 2023). Cultural practices that influence yield and pest reaction include: 1) rotation sequence of previous crops (Jordan et al., 2003, 2008a, 2008b, 2009a, 2009b, 2017), 2) tillage (Jordan et al., 2001, 2008a), 2) planting pattern and plant density (Jordan et al., 2001a, 2010c; Lanier et al., 2004a; Oakes at al., 2020), 3) soil pH and calcium nutrition (Jordan and Barnes, 2021; Jordan et al., 2010b, 2020b), 4) plant architecture as influenced by plant growth regulators (Beam et al., 2002; Jordan et al., 2001b, 2009c), 5) inoculation with bacteria for biological nitrogen fixation (Jordan et al., 2009a, 2010a, 2018; Lanier et al., 2005), 6) planting date (Jordan et al., 2019; Mahoney et al., 2019), 7) digging date (Carley et al., 2009; Jordan et al., 2016; Oakes et al., 2020), and irrigation (Lanier et al., 2004b). Each of these practices can be influenced cultivar selection both within and across botanical classifications and market types (Drake et al.,2009; Faircloth et al., 2005; Hurt et al., 2004, 2005; Jordan et al., 2008, 2010, 2019; Lassiter et al., 2016a, 2016b; Monfort et al., 2021). Determining how these practices interact with commercially available cultivars, promising new breeding lines, and alternative market types can inform practitioners and their advisors on what combination of practices are most effective for a particular market type and variety. Previous research has addressed many of these practices with cultivars serving as treatment factor. However, data are limited with several of the more recently released virginia-market type cultivars. To address this limitation in information, research will be conducted in all states interested to compare virginia-type cultivar response under various cultural practices.

General Procedure

Project leaders from collaborating institutions will conduct some but not all of the following trials in their state. The goal is that by the time the five-year project is complete, each of the following experiments will have been conducted in multiple states at multiple locations. Although specific cultivars are listed here, as projects are planned, additional cultivars or promising lines can be added. Data from these trials will be used to estimate the cost-return of production with different scenarios of cultural practices.

Rotation Sequence and Cultivars

A rotation sequence of two years of cotton and then peanut, peanut-cotton-peanut, and soybean-cotton-peanut will be established with five levels of variety planted in the final year. Varieties will include Bailey II, Emery, NC 20, NC 21, Tift Jumbo, and Walton. Plant parasitic nematodes in soil, nematode injury to root systems, disease reaction, and peanut yield will be determined.

Tillage System and Cultivars

Conventional, strip-till, and no-till plots will be established and response of Bailey II, Emery, NC 20, NC 21, Tift Jumbo, and Walton. Disease reaction, pod yield, and market grade characteristics will be determined. These data will be used to estimate the financial return to the grower as the result of adoption of different tillage systems on different cultivars.

Planting Patterns, Plant Density, and Cultivars

The cultivars Bailey II, Emery, NC 20, NC 21, TifJumbo, and Walton will be established in single and twin row planting patterns at densities of 4 and 6 seed per foot of row. Pest reaction, peanut yield, and market grade characteristics will be determined. These data will be used to estimate the financial return to the grower as the result of adoption of different planting patterns and seeding rates for each cultivar.

Soil pH, Calcium Nutrition, and Cultivars

The cultivars Bailey II, Emery, NC 20, NC 21, TifJumbo, and Walton will be established in areas of fields with low pH (~5.5) and optimal pH (~6.2) with calcium sulfate treatments including a non-treated control and the recommended rate for the available calcium sulfate product.

Plant Architecture and Cultivars

The cultivars Bailey II, Emery, NC 20, NC 21, TifJumbo, and Walton will be treated with prohexadione calcium applied once or twice compared with non-treated peanut.

Inoculation for Biological Nitrogen Fixation and Cultivars

The cultivars Bailey II, Emery, NC 20, NC 21, TifJumbo, and Walton will be treated with a commercially available inoculant for biological nitrogen fixation compared with a non-inoculated control.

Planting Dates and Cultivars

The cultivars Bailey II, Emery, NC 20, NC 21, TifJumbo, and Walton will be planted approximately May 1, May 20, and June 10.

Digging Dates and Cultivars

The cultivars Bailey II, Emery, NC 20, NC 21, TifJumbo, and Walton will be planted in mid-May and dug at intervals of 10 days apart beginning in early September and continuing through mid-October.

Objective 3: Demonstrate effectiveness of current and novel pest management control systems across the Virginia-type peanut production belt.

Extension recommendations for commercial production of virginia-type peanut include management of weed, insect, and disease pests to protect pod yield and quality of a peanut crop (Anco et al. 2023; Balota et al. 2023; Jordan et al. 2023). Competition from weeds can reduce light available for photosynthesis and consequent pod production in peanut and can interfere with effective inversion (Anco et al. 2023; Hare et al. 2019; Jordan et al. 2023; Wilcut and Askew 1999). Research has demonstrated compatibility of currently available herbicides with standard cultivars when applied at labeled rates and timings (e.g., flumioxazin and paraquat) (Basinger et al. 2021; Price et al. 2020), but information demonstrating crop safety/resilience in the presence of characteristic phytotoxicity is lacking for newly released cultivars. Thrips (e.g., Frankliniella fusca and F. occidentalis) are endemic insect pests in the VC region due to their feeding injury (Brandenburg et al. 2019; Chahal et al. 2014) and capacity to vector Tomato spotted wilt virus, the virus that causes tomato spotted wilt (TSW) which also can lead to reductions in yield and crop profitability (Anco et al. 2020B; Srinivasan et al. 2017). While product price, farmer preference, and cultivar susceptibility to TSW each contribute to determining which in-furrow insecticide is applied, establishing a database of the relative susceptibility of newly released cultivars to thrips feeding injury and TSW will provide valuable context from which advisors may recommend specific practices and products. Late or early leaf spot (caused by Nothopassalora personata and Passalora arachidicola, respectively) and southern stem rot/white mold (caused by Athelia rolfsii) diseases are yield and value-limiting biotic stresses (Anco et al. 2020A; Bowen 2003; Shew and Beute 1984; Singh et al. 2011). An increased understanding on the relative susceptibility of newly released cultivars to these fungal diseases will allow targeted recommendation and implementation of available practices to manage these diseases and mitigate corresponding adverse economic impacts (Mehl, 2017).

General Procedure

Project leaders from collaborating institutions will conduct some but not all of the following trials in their state. The goal is that by the time the five-year project is complete, each of the following experiments will have been conducted in multiple states at multiple locations. Although specific cultivars are listed here, as projects are planned additional cultivars or promising lines can be added. Data collected from these trials will be used to estimate the cost-return of the production when using different herbicides, insecticides, and fungicides.

Herbicide Compatibility

Bailey II, Emery, NC 20, NC 21, TifJumbo, and Walton will be grown under-stand production practices and treated with recommended herbicides, including flumioxazin, paraquat, pendimethalin, and 2,4-DB and observed for phytotoxicity and yield effects against non-treated checks.

Insecticide Compatibility and TSW Susceptibility

Bailey II, Emery, NC 20, NC 21, TifJumbo, and Walton will be grown under-stand production practices to compare thrips feeding injury circa 28 days after planting (DAP) and TSW incidence circa 70 DAP for cultivars treated with imidacloprid or phorate in-furrow at planting. Yield will be quantified to compare cultivar response. TSW susceptibility will also be quantified in allied tests (e.g., tests designed to compare agronomic performance under different planting dates).

Late/Early Leaf Spot and Stem Rot Susceptibility

Bailey II, Emery, NC 20, NC 21, TifJumbo, and Walton will be grown under a reduced management schedule (e.g., half the number of standard chlorothalonil applications) in order to facilitate advanced development of leaf spot infections from which relative susceptibilities of cultivars will be able to be determined. Where available, tests will be grown under irrigation to establish conducive conditions for infection. Defoliation caused by late or early leaf spot will be quantified as it develops, with ratings conducted approximately every two weeks through to harvest. Stem rot incidence will be quantified at inversion, with yield quantified. If natural infection levels are inadequate among available test sites, inoculations will be performed. Related tests designed to compared agronomic performance of cultivars will be examined at inversion for presence of stem rot infections, with ratings taken where infections are observed to compare susceptibility profiles of cultivars.

Objective 4. Exploit the genetic and physiological bases for adaptation to climate change to improve peanut cultivar development.

Collaborative research among scientists in the VC, SE, and SW peanut growing regions clearly showed that resilience to climate change is possible through exploration of genetic diversity and high-throughput phenotyping approaches (NIFA-AFRI grant no.- 2017-67013-26193) (Sarkar, 2020). Under this objective, a suite of experiments (Tasks 4.1, 4.2., and 4.3.) will be conducted in all peanut growing regions of the USA interested to participate.

General procedures

A combination of field and controlled growth environments will be used to characterize key physiological responses to heat stress and combined heat and drought stress. These data will be coupled with existing genomic resources, generated under S-1079, USDA NIFA AWARD # 2016-08666, and NIFA-AFRI grant no.-2023-67013-39624, to identify genomic regions and genetic markers associated with climate resilience. Additionally, we will integrate transcriptomic data collected under controlled growth conditions (field and chamber) to identify physiological and genetic regulatory mechanisms that shape peanut responses to elevated temperature. Finally, we will use field evaluations of existing cultivars and material in the breeding pipeline to identify germplasm that is climate resilient.

Phenotyping:  From cultivars and lines, we will collect Normalized Difference Vegetation Index (NDVI), relative chlorophyll content (SPAD), Canopy Temperature Depression (CTD), flower number, pollen viability, seed size, harvest index, canopy height (HT), plant width, wilting, photosynthesis, and pod yield. Daily temperature readings will be collected over the course of the growing season. Timing of these measurements is important to maximize their predictive power. NDVI, SPAD, and wilting will be measured over 2-week intervals x times over the growing season, following Sarkar (2021) and (Sarkar et al., 2021). Critical days for pollen development and flower production are from -6 to 15 days after first flower (DAF) for spanish and virginia-type peanuts (Prasad et al. 1999), thus CTD, pollen, and flower number will be collected daily during the interval from 30 days after planting to 55 days after planting. Plant morphometric data will be assessed weekly throughout the growing season. Finally, plants will be mechanically harvested to estimate yield.

 

Pollen collection and staining: Peanut is cleistogamous therefore pollen will be collected on wet ice from 10 unopened flowers per RIL per day during flower production and then stored at -80 C until ready for staining. Pollen will be released from the flowers via tissue disruption and passed through a 40µm filter to remove flower material leaving pollen. Pollen from each RIL will be soaked in a 25% Lactophenol-Aniline blue solution for 20 minutes and then 10mL mounted on a hemacytometer for counting under 40X magnification. A digital image of each sample will be obtained and pollen counting will be automated using ImageJ (Costa and Yang 2009) and a random-forest image classifier that will be trained on human validated images. Deformed and unstained pollen grains will be considered inviable.

 

Genotyping: For these populations we have already identified 1596 informative SNP markers using genotyping by sequencing, that have been used to generate linkage maps and map QTL associated with drought tolerance in peanut (Kumar 2022). We will supplement these with additional sequencing coverage of individuals as needed.

Transcriptomics: To elucidate the physiological and genetic mechanisms underlying these responses we will conduct an RNAseq experiment in controlled environment chambers. Seed will be germinated under 30/25^°C and 40/60% Rh day/night. At 30 DAP plants (prior to the critical period described above) will be randomized to treatments and placed in chambers at 30/25^°C and 40/35^°C temperatures with 40/60% Rh day/night in each chamber, flowers will be collected as in objective 1 daily from 35DAP-55DAP. For each line, 3 biological replicate pools will be sequenced via the NovaSeq 6000 platform using 2 x 150bp reads. Raw reads will be processed and analyzed following standard pipelines in the Haak Lab (Cui 2019). Genes identified as differentially expressed will be validated using qPCR and used to develop markers for application in genomic selection and traditional breeding programs.

Objective 5: Expand the use of “smart” technologies in precision breeding and management of Virginia-type peanut.

Under this objective, our major goal is to develop high-throughput and non-invasive techniques for determining pod maturity and water stress. This will be achieved by using data inputs of aerial multispectral imaging, smartphone-based thermal imaging, and weather through state-of-the-art machine learning and crop biophysical modeling. Expected outputs will be site-specific decisions on irrigation management and peanut pod harvesting. 

Water stress

Water stress in peanuts is a major concern caused by drought, extreme temperatures, and weather events that can decline yield, quality, and overall grower profitability up to 92% (Fahad et al., 2017). Mis-timed and unmitigated irrigation management leads to under or over-application of freshwater which ultimately raises sustainability concerns. Therefore, it becomes critical to promptly mitigate and manage water stress in real/near-real-time not only to prevent crop loss but minimize water usage. However, no such tool or technique is available to-date that assesses or guides precision irrigation management. Conventional water stress estimation methods are destructive, tedious, limited in sampling accuracy, and time intensive (Slavik, 1974; Turner, 1981; Fariñas et al., 2019). If water stress management is not conducted in near- or real-time, then strass mitigation could be inefficient (Chandel et al., 2021). Thus far, there is no seamless handy tool that could be used by the growers of peanuts to determine water stress levels in real/near-real time for precision irrigation application.

Pod Maturity

Peanuts are the indeterminate and continuously setting crop and do not mature evenly throughout a field. Therefore, deciding on the optimum peanut harvesting time has been the biggest challenge for all the growers in the US and globally. Pre-mature and over-mature harvest results into yield, quality, and economic losses (Lopez et al., 2001). Conventionally, the “pod blasting” method in which mesocarp color is manually visualized, is used to decide the harvesting time (Williams and Drexler 1981). In this method peanuts are dug randomly from only one location in a field and pod color is visually observed by a trained expert to subjectively determine the days to optimum maturity. This approach is very tedious and expensive when it comes to identify field-level representable maturity due to heavy sampling and observation requirements. This method would also require multiple digging events over the season to keep a track of maturity progression. In nutshell, such manual approach offers minimal accountability for in-field spatiotemporal variations in the peanut maturity leading to digging out either over-matured or pre-mature peanuts (Carley et al. 2008; Rowland et al., 2006).

General Procedure

Water stress

The Virginia-type peanut cultivars planted as part of the breeding trials i.e., Bailey II, Emery, NC 20, NC 21, TifJumbo, and Walton, under different plantation settings of crop rotation, tillage, planting densities, soil pH, Calcium nutrition, and planting dates will be leveraged for this aspect. Imaging campaigns will be conducted at 15-day internal using A Flir one Pro (Flir Teledyne Systems, Wilsonville, OR) smartphone-enabled thermal camera. In tandem, reference stress measurements will be acquired using a photosynthesis measurement system (LI-COR 6800, LI-COR Biosciences, Lincoln, NE) and leaf porometer. Acquired thermal images will be processed through a custom developed algorithm to determine pixelated and mean crop water stress index (Jackson et al., 1981). Mean estimates will be validated against corresponding reference water stress measurements and impacts on pod yield will be established.

 

Pod maturity

The Virginia-type peanut cultivars planted as part of the breeding trials i.e., Bailey II, Emery, NC 20, NC 21, TifJumbo, and Walton, under different plantation settings of crop rotation, tillage, planting densities, soil pH, Calcium nutrition, and planting dates will be leveraged for this aspect. Drone flight missions with 5-band multispectral imaging will be conducted at 20 m above ground (spatial resolution: 1.4 cm/pixel) at an interval of 10 days starting early September through mid-October. At the same time, peanut pods will be dug out. Collected pod samples will be blasted using pressurized water and then placed on the maturity board to count the numbers of white (W), yellow (Y), orange (O), brown (Br), and black (Bl) pods. Maturity indexes (PMI-1 and -2) will be calculated where PMI-1 is the ratio of sum total of orange, brown, and black pods to the total number of pods and PMI-2 is the sum total of brown, and black pods to the total number of pods. 25 Vegetation indices will be derived from multispectral imagery and evaluated for correlations with maturity indices. Machine learning models will also be formulated using inputs of spectral reflectance and weather data to predict maturity indices. Accurate prediction models/relationships will be used to develop site-specific maturity variation maps towards harvest planning. Data collected over multiple years and planting conditions will be instrumental in improving the accuracies of maturity prediction models.

Measurement of Progress and Results

Outputs

• Annual USDA reports will include comparisons of the current cultivars with new breeding lines for yield and grade characteristics, information on improved management practices and efficacy of new products to control pests, methods and measures to improve high-throughput phenotyping and remote sensing for crop management, and genomic and phenomic research results that are important for further development of sustainable cultivars under changing environmental conditions. Data presented will determine the suitability of future cultivars for the in-shell and roasted peanut markets. On varieties, results will include growth habit, yields, grades, and projected market value. Information from the rainout shelter testing, including wilting severity and timing, physiological mechanisms for response to stress, and molecular markers will allow selection of more drought and heat tolerant cultivars. Disease and insect resistance/susceptibility genotypic data will also be included. Reports will also include information on herbicides and pesticides compatibility for control of major weeds, insect pests, and diseases within in each participating state. Information on the cultural practices mostly prone to affect peanut yield, either by promoting overall health and nutrition of peanut, and sustainability will become available not just through the USDA reports but also Extension publications. Presentation of data will be made to the Multistate Hatch S1079 Executive Committee as well as at appropriate industry and professional meetings. Papers on varieties, management practices, genomic and phenomic findings, and remote sensing applications will be published in appropriate scientific journals. Data will be sufficient to make knowledge-based decisions for sustainable Virginia-type peanut production not just in the VC region, but also across the entire peanut belt in the USA.

Outcomes or Projected Impacts

• The goal is that by the time of project ending, in 2028, complete information gathered from all objectives will be sufficient to allow knowledge-based decisions for cultivar releases and management procedures to allow sustainable peanut production in the VC region and the other Virginia-type growing regions in the USA. New cultivars will be early maturing, resistant to climate change and with quality to meet all segments of the peanut industry for the Virginia-type peanut. Management procedures will be improved and information will be made available to the growers within the Virginia-type peanut belt for more sustainable peanut production. The genetic and physiologic bases for peanut adaptation to changing climate, extreme temperature and rainfall in particular, will be elucidated and high-throughput genomic and phenomic tools will be available for the peanut breeding programs in the country. Remote sensing technologies will become available for breeding and for crop management, and breeders and growers will have the available information to use these technologies, when available. Smartphone-thermal imaging capability to quantify peanut crop water stress will be established and validated for enhanced robustness. Seamless smartphone application to capture thermal images and deliver water stress estimates in real time will be the next stage of this project that will be ultimately useful for spatiotemporal irrigation management. As outcome of maturity estimation aspect, we expect to deliver a robust and generalized peanut maturity prediction model. Developed model will have potentials of getting converted to a decision support tool to be used by the growers to predict peanut maturity and plan on harvest strategies and resources based on their local crop and environment conditions. The information developed in this study will be useful to the breeders and researchers for developing stress tolerant, high yielding, and quality peanut cultivars. We expect publishing the findings in peer-reviewed journals and extension articles.

Milestones

(2023):Obj. 1. Advanced virginia-type breeding lines from the participating breeding programs will be tested for agronomic and grade characteristics needed by all segments of the peanut industry. Variety testing will take place in all participating states, as needed. Elite line(s) will be considered for release by the end of the project; Research will be presented and published. (All virginia-type peanut breeding and/or production states)

(2023):Obj. 2. Project leaders from collaborating institutions will conduct agronomic trials in their state, according to the protocols collectively developed. The goal is that by 2028, each of the following experiments will have been conducted in multiple states at multiple locations. The data collected from these trials will be used to refine agronomic recommendations for virginia-type peanut production guides and also presented and published. (All virginia-type peanut breeding and/or production states)

(2023):Obj. 3. Project leaders from collaborating institutions will conduct pesticide trials in their state, according to the protocols collectively developed. The goal is that by 2028, each of the following experiments will have been conducted in multiple states at multiple locations. The data collected from these trials will be used to refine agronomic recommendations for virginia-type peanut production guides and also presented and published. (All virginia-type peanut breeding and/or production states)

(2023):Obj. 4. By the end of this project, collaborators will identify genomic regions and genetic markers associated with climate resilience, and the phenotypes associated with the genomic regions that, in connection with Obj. 5 below, can be used for high-throughput selection. (All virginia-type peanut breeding and/or production states)

(2023):Obj. 5. By the end of this project, collaborators will develop high-throughput and non-invasive techniques for determining pod maturity and water stress. (All virginia-type peanut breeding and/or production states)

Projected Participation

View Appendix E: Participation

Outreach Plan

Findings will be published by the investigators in annual reports, discussed in production meetings, and will be used to update the current information provided by Peanut Production Guides of each participating state. These findings will be published in appropriate refereed journals and Extension publications.

Organization/Governance

The management structure of the project will consist in a Chair, Vicechair, and Secretary.  These Positions will rotate upward from a Secretary (nominated and elected annually) to the vice-chair and then the chair, over a 3-year rotation.  These three individuals will make up the Executive Committee of the Multistate hatch and will be responsible for all logistics related to the meetings as required by the USDA reporting. Each of the five objectives, will represent sub-committees, each with a Chair that reports to the Executive Committee.

Literature Cited

Alexander, M.W., and R.W. Mozingo. 1972. Registration of 'Virginia 72R' peanuts (Reg. No. 13). Crop Sci. 12: 127.

Amogi, B.R., Chandel, A.K., Khot, L.R., Jacoby, P.W., 2020, November. A mobile thermal-RGB imaging tool for mapping crop water stress of grapevines. In 2020 IEEE International Workshop on Metrology for Agriculture and Forestry (MetroAgriFor), 293-297.

Anco, D. J., Thomas, J. S., Shew, B., Jordan, D., Monfort, W., Mehl, H., Small, I., Wright, D., Tillman, B., Dufault, N., Hagan, A., and Campbell, H. 2020a. Peanut yield loss in the presence of defoliation caused by late or early leaf spot. Plant Dis. 104:1390-1399.

Anco, D., Marshall, M., Kirk, K.R., Plumblee, M.T., Smith, N., Mickey, S., Farmaha, B., and Payero, J. 2023. Peanut Money-Maker 2023 Production Guide. Clemson University Extension, Circular 588.

Anco, D.J., Thomas, J.S., and Monfort, W.S. 2020b. Efficacy and profitability of insecticide treatments for tomato spotted wilt management on peanut in South Carolina. Plant Disease 104:1096-1104.

Balota, M., and Isleib, T.G. 2020. Registration of ‘GP-VT NC 01’ peanut germplasm. J. Plant Reg. 14(2): 172-178. doi:10.1002/plr2.20028.

Balota, M., Cherry, W. F., Tillman, B.L. 2022c. Development of peanut cultivars with the University of Florida: performance of Florida breeding lines in Virginia. Proceeding 54^th Annual Meeting Am. Peanut Res. Ed. Soc. July 12-14, Dallas, TX, 2022.

Balota, M., J. C. Dunne, D. Anco, F. Cherry. 2022b. Peanut Variety and Quality Evaluation results I: 2021 quality data. Virginia Tech and Virginia Coop. Ext. Publ. SPES-395NP.

Balota, M., J. Dunne, D. Anco, F. Cherry. 2022a. Peanut Variety and Quality Evaluation results I: 2021 agronomic and grade data. Virginia Tech and Virginia Coop. Ext. Publ. SPES-382NP. 44 p.

Balota, M., Mozingo, W. R., Coffelt, T. A., Isleib, T. G., Beahm, B. R., Pittman, H. G., Bryant, F. S., Copeland, P. A., Daughtrey, C. J., Kennedy, B. C., Shokes, F. M., Ashburn, Jr., R. D., Whitt, D. L. and Redd, D. A., 2011. Registration of ‘Titan’ peanut. J. Plant Reg. 5:282-288.

Balota, M., T.G. Isleib, J. Oakes, and J. Chapin. 2016. Microsoft Word - 2015 Peanut Variety and Quality Evaluation Book l (v2)-2a.docx.

Balota, M., Tillman, B.L., Paula-Moraes, S.V., and Anco, D. 2021. ‘Walton’, a new virginia-type peanut suitable for Virginia and northern U.S. growing regions. Journal Plant Registrations https://doi.org/10.1002/plr2.20143.

Balota, M.; Jordan, D.; Langston, D.; Shortridge, J.; Taylor, S. 2023. Virginia Peanut Production Guide; Virginia Cooperative Extension: Suffolk, VA, USA, 2023.

Basinger, N.T., Randell, T.M., and Prostko, E.P. 2021. Peanut response to flumioxazin and s-metolachlor under high moisture conditions. Peanut Science 48:113-117.

Beam, J.B., D.L. Jordan, A.C. York, T.G. Isleib, J.E. Bailey, T.E. McKemie, J.F. Spears, and P.D. Johnson.  2002.  Influence of prohexadione calcium on pod yield and pod loss of peanut. Agron. J. 94:331-336.  [Erratum: 2002.  Agron J. 94: 955.]

Bowen, K.L. 2003. Development of stem rot (caused by Sclerotium rolfsii) in peanut in Alabama. Peanut Science 30:120-128.

Branch, W.D. and T.B. Brenneman. 2020. Registration of ‘Georgia-19HP’ peanut. J. Plant Reg. 14 (3):306-310. https://doi.org/10.1002/plr2.20037

Brandenburg, R. L., Jordan, D. L., Royals, B. R., Mahoney, D. J., and Johnson, P. D. 2019. Utilization of imidacloprid to control thrips in peanut in North Carolina. Peanut Sci. 46:8-13

Campbell, W.V., J.C. Wynne, D.A. Emery, and R.W. Mozingo. 1977. Registration of 'NC6' peanuts (Reg. No. 20). Crop Sci. 17: 346.

Carley, D.S., Jordan, D.L., Dharmasri, L.C., Sutton, T.B., Brandenburg, R.L., Burton, M.G., 2008. Peanut response to planting date and potential of canopy reflectance as an indicator of pod maturation. Agron. J. 100(2): 376-380.

Carley, D.S., D.L. Jordan, B.B. Shew, T.B. Sutton, L.C. Dharmasri, and R.L. Brandenburg.  2009.  Influence of digging date and fungicide program on canopy defoliation and pod yield of peanut (Arachis hypogaea L.).  Peanut Sci.  36:77-84.

Chahal, G.S., Jordan, D.L., Eure, P.M., and Brandenburg, R.L. 2014. Compatibility of acephate with herbicides applied postemergence in peanut. Peanut Science 41:58-64.

Chamberlin, K.D., R.S. Bennett, J.P. Damicone. 2019. Registration of ‘Contender’ peanut. J. Plant Reg. 13(2): 139-142. https://doi.org/10.3198/jpr2018.09.0060crc

Chamberlin, K.D., R.S. Bennett, T.G. Isleib, S. Copeland, J.S. Dunne. 2022. Registration of ‘Comrade’ peanut. J. Plant Reg. 16:533-539. DOI: 10.1002/plr2.20233

Chandel, A.K., Khot, L.R., Yu, L.X., 2021. Alfalfa (Medicago sativa L.) crop vigor and yield characterization using high-resolution aerial multispectral and thermal infrared imaging technique. Computers and Electronics in Agriculture, 182, p.105999.

Coffelt, T.A., D.M. Porter, and R.W. Mozingo. 1982. Registration of 'Virginia 81 Bunch' peanut (Reg. No. 25). Crop Sci. 22: 1085-1086.

Coffelt, T.A., D.M. Porter, and R.W. Mozingo. 1994. Registration of 'VA 93B' peanut. Crop Sci. 34(4): 1126.

Costa, C.M. and Yang, S., 2009. Counting pollen grains using readily available, free image processing and analysis software. Annals of Botany, 104(5), pp.1005-1010.

Cui, C., 2019. Integrating bioinformatic approaches to promote crop resilience (Doctoral dissertation, Virginia Tech).

Drake, W.L., D.L. Jordan, R.L. Brandenburg, B.R. Lassiter, P.D. Johnson, and B.M. Royals.  2009.  Peanut cultivar response to damage from tobacco thrips and paraquat.  Agron. J.  101:1388-1393.

Dunne, J.C., R.J. Andres, and A.T. Oakley. 2022. Release of a virginia-type cultivar, ‘N.C. 20’, for the Virginia-Carolinas production region. American Peanut Res.Edu. Soc. Annual meeting, July 12-14, 2022, Dallas, TX.

Emery, D.A. 1970. Registration of 'NC17' peanuts (Reg. No. 7). Crop Sci. 10: 460.

Emery, D.A., A.J. Norden, J.C. Wynne, and R.W. Mozingo. 1974. Registration of 'NC-Fla 14' peanuts (Reg. No. 17). Crop Sci. 14: 494.

Erickson, P.I., and D.L. Ketring. 1985. Evaluation of Peanut Genotypes for Resistance to Water Stress in Situ. Crop Science 25(5): 870–876.

Fahad, S., Bajwa, A.A., Nazir, U., Anjum, S.A., Farooq, A., Zohaib, A., Sadia, S., Nasim, W., Adkins, S., Saud, S., Ihsan, M.Z., 2017. Crop production under drought and heat stress: plant responses and management options. Frontiers in Plant Science, p.1147.

Faircloth, J.C., D.L. Coker, C. W. Swann, R. W. Mozingo, P. M. Phipps, and D.L. Jordan.  2005.  Response of four Virginia-type peanut cultivars to prohexadione calcium as affected by cultivar and planting pattern.  Peanut Sci.  32:42-47.

Fariñas, M.D., Jimenez-Carretero, D., Sancho-Knapik, D., Peguero-Pina, J.J., Gil-Pelegrín, E., Gómez Álvarez-Arenas, T., 2019. Instantaneous and non-destructive relative water content estimation from deep learning applied to resonant ultrasonic spectra of plant leaves. Plant Methods, 15(1), 1-10.

Hare, A.T., Jordan, D.L., Leon, R.G., Edmisten, K.L., Post, A.R., Mahoney, D.J., and Washburn, D. 2019. Impact of weed management on peanut yield and weed population the following year. Peanut Science 46:182-190.

Hurt, C.A., R.L. Brandenburg, D.L. Jordan, G.G. Kennedy, and J.E. Bailey.  2004.  Effect of cultivar and plant population on spotted wilt virus in virginia market type peanut.  Peanut Sci. 31:101-107.

Hurt, C.A., R.L. Brandenburg, D.L. Jordan, B.M. Royals, and P.D. Johnson.  2005.  Interactions of tillage with management practices designed to minimize tomato spotted wilt of peanut (Arachis hypogaea L.).  Peanut Sci. 32:83-89.

Isleib, T. G., Milla-Lewis, S. R., Pattee, H. E., Copeland, S. C., Zuleta, M. C., Shew, B. B., Hollowell, J. E., Sanders, T. H., Dean, L. O., Hendrix, K. W., Balota, M., Chapin, J. W., and Monfort, W.S. 2015. Registration of ‘Sugg’ peanut. J. Plant Reg. 9:44-52. doi:10.3198/jpr2013.09.0059crc.

Isleib, T. G., S. R. Milla-Lewis, H. E. Pattee, S. C. Copeland, M. C. Zuleta, B. B. Shew, J. E. Hollowell, T. H. Sanders, L. O. Dean, K. W. Hendrix, M. Balota and J. W. Chapin. 2011. Registration of ‘Bailey’ peanut. J. Plant Reg. 5:27-39.

Isleib, T.G., P.W. Rice, J.E. Bailey, R.W. Mozingo, and H.E. Pattee. 1997. Registration of 'NC 12C' peanut. Crop Sci. 37(6): 1976.

Isleib, T.G., P.W. Rice, R.W. Mozingo II, R.W. Mozingo, J.E. Bailey, and H.E. Pattee. 2003. Registration of 'Perry' peanut. Crop Sci. 43: 739-740.

Isleib, T.G., P.W. Rice, R.W. Mozingo II, S.C. Copeland, J.B. Graeber, W.F. Novitzky, H.E. Pattee, T.H. Sanders, R.W. Mozingo, and D.L. Coker. 2006 a. Registration of 'Brantley' peanut. Crop Sci. 46: 2309-2311.

Isleib, T.G., P.W. Rice, R.W. Mozingo II, S.C. Copeland, J.B. Graeber, H.E. Pattee, T.H. Sanders, R.W. Mozingo, and D.L. Coker. 2006 b. Registration of 'Phillips' peanut. Crop Sci. 46: 2308-2309.

Isleib, T.G., P.W. Rice, R.W. Mozingo, R.W. Mozingo II, and H.E. Pattee. 1999. Registration of 'Gregory' peanut. Crop Sci. 39(5): 1526.

Jackson, R.D., Idso, S.B., Reginato, R.J., Pinter Jr, P.J., 1981. Canopy temperature as a crop water stress indicator. Water Resources Research, 17(4), 1133-1138.

Jordan, D., D. Hardy, S. Barnes, and T. Corbett.  2020b.  Potential economic value for peanut by increasing soil pH in North Carolina.  J. Crop, Forage, and Turfgrass Management.  Vol. 6. DOI: 10.1002/cft2.20012.

Jordan, D., P.D. Johnson, and T. Corbett.  2019.  Response of two Virginia market type peanut cultivars to planting and digging dates in North Carolina.  J. Crop, Forage, and Turfgrass Management.  Vol. 5.  doi:10.2134/cftm2019.01.0003.

Jordan, D.L. and J.S. Barnes.  2020.  Peanut response to interactions of soil pH and gypsum.  Archives of Agriculture Research and Technology.  1 (4): 2020.

Jordan, D.L., B.B. Shew, and P.D. Johnson.  2016.  Response of the peanut (Arachis hypogaea L.) cultivar Gregory to interactions of digging date and disease management.  Advances in Agriculture, Volume 2016, Article ID 5839090.

Jordan, D.L., B.B. Shew, J.S. Barnes, T. Corbett, J. Alston, P.D. Johnson, W. Ye, and R.L. Brandenburg.  2008b.  Pest reaction, yield, and economic return of peanut based cropping systems in the North Carolina coastal plain.  J. Crop Management.  doi:10.1094/CM-2008-1008-01-RS.

Jordan, D.L., D. Auman, R.L. Brandenburg, A.B. Brown, G. Buol, J. Dunne, D. Reisig, G.T. Roberson, B. Shew, and D. Washburn. 2023. 2023 Peanut Information. NC State Extension Pub. AG-331.

Jordan, D.L., D. Auman, R.L. Brandenburg, A.B. Brown, G. Buol, J. Dunne, D. Reisig, G.T. Roberson, B. Shew, and D. Washburn. 2023. 2023 Peanut Information. NC State Extension Pub. AG-331.

Jordan, D.L., G. Place, R.L. Brandenburg, J.E. Lanier, and D.S. Carley.  2010c.  Response of virginia market type peanut to planting pattern and herbicide program.  J. Crop Management.  doi:10.1094/CM-2010-0430-01-RS.

Jordan, D.L., G.S. Buol, R.L. Brandenburg, B.B. Shew, G.G. Wilkerson, B.R. Lassiter, J. Dunne, A. Gorny, D. Washburn, D. Hoisington, and J. Rhoads. 2022. A risk tool and production log created using Microsoft Excel to manage pests in peanut (Arachis hypogaea). Journal of Integrated Pest Management. 13(1):9.1-16.

Jordan, D.L., J. Dunne, H.T. Stalker, B.B. Shew, R.L. Brandenburg, D. Anco, H. Mehl, S. Taylor, and M. Balota.  2020a.  Risk to sustainability of pest management tools in peanut. Agricultural and Environmental Letters.  Volume 5.  doi.org/10.1002/ael2.20018.

Jordan, D.L., J.B. Beam, P.D. Johnson, and J.F. Spears.  2001b.  Peanut response to prohexadione calcium in three seeding rate-row pattern planting systems.  Agron. J.  93:232-236.

Jordan, D.L., J.S. Barnes, C.R. Bogle, G.C. Naderman, G.T. Roberson, and P.D. Johnson.  2001a.  Peanut response to tillage and fertilization. Agron. J. 93:1125-1130.

Jordan, D.L., J.S. Barnes, C.R. Bogle, R.L. Brandenburg, J.E. Bailey, P.D. Johnson, and A.S. Culpepper.  2003.  Peanut response to cultivar selection, digging date, and tillage intensity.  Agron. J. 95:380-385.

Jordan, D.L., J.S. Barnes, T. Corbett, C.R. Bogle, P.D. Johnson, B.B. Shew, S.R. Koenning, W. Ye, and R.L. Brandenburg.  2008a.  Crop response to rotation and tillage in peanut-based cropping systems.  Agron. J.  100:1580-1586.

Jordan, D.L., J.S. Barnes, T. Corbett, C.R. Bogle, T. Marshall, and P.D. Johnson.  2009a.  Influence of crop rotation on peanut (Arachis hypogaea L.) response to Bradyrhizobium in North Carolina.  Peanut Sci. 36:174-179.

Jordan, D.L., L.R. Fisher, B.B. Shew, T. Marshall, P.D. Johnson, W. Ye, and R.L. Brandenburg.  2009b.  Comparison of cropping systems including corn, peanut, and tobacco in the North Carolina Coastal Plain.  J. Crop Management.  doi:10.1094/CM-2009-0612-01-RS.

Jordan, D.L., P.D. Johnson, A.T. Hare, D. Anco, J. Chapin, J. Thomas, S. Monfort, M. Balota. 2018.  Influence of inoculation with Bradyrhizobia and nitrogen rate on yield and estimated economic return of Virginia market type peanut.  J. Crop, Forage, and Turfgrass Management.  Vol. 4.  doi:10.2134/cftm2018.01.0002.

Jordan, D.L., P.D. Johnson, J.F. Spears, B. Penny, and D. Hardy.  2010b.  Response of Virginia market type peanut to interactions of cultivar, calcium, and potassium.  J. Crop Management.  doi:10.1094/CM-2010-0226-01-RS.

Jordan, D.L., P.D. Johnson, R.L. Brandenburg, and J. Faircloth.  2010a.  Peanut (Arachis hypogaea L.) response to Bradyrhizobia applied in-furrow with agrichemicals.  Peanut Sci.  37:32-38.

Jordan, D.L., R.C. Nuti, J.B. Beam, S.H. Lancaster, J.E. Lanier, and P.D. Johnson.  2009c.  Influence of application variables on peanut (Arachis hypogaea L.) response to prohexadione calcium.  Peanut Sci. 36:96-103.

Jordan, D.L., T. Corbett, C. Bogle, B. Shew, R. Brandenburg, and W. Ye.  2017.  Effect of previous rotation on plant parasitic nematode population in peanut and crop yield.  J. Crop, Forage, and Turfgrass Management.  Vol. 3: doi:10.2134/cftm2016.12.0086.

Kumar, N., 2022. Leveraging genomic mapping and QTL analysis to enhance drought tolerance of cultivated peanut (Arachis hypogaea L.) (Doctoral dissertation, Virginia Tech).

Kumar, N.; Haak, D.C.; Dunne, J.C.; Balota, M. 2022. Multilocation Evaluation of Virginia and RunnerType Peanut Cultivars for Yield and Grade in Virginia–Carolina Region. Agronomy 2022, 12, 3206. https://doi.org/10.3390/ agronomy12123206

Lanier, J.E., D.L. Jordan, J.F. Spears, R. Wells, and P.D. Johnson.  2005.  Peanut response to inoculation and nitrogen fertilizer.  Agron. J.  97:79-84.

Lanier, J.E., D.L. Jordan, J.F. Spears, R. Wells, P.D. Johnson, J.S. Barnes, C.A. Hurt, and R.L. Brandenburg.  2004a.  Peanut response to planting pattern, row spacing, and irrigation.  Agron. J.  96:1066-1072.

Lanier, J.E., D.L. Jordan, J.S. Barnes, J. Matthews, G.L. Grabow, W.J. Griffin, Jr., J.E. Bailey, P.D. Johnson, J.F. Spears, and R. Wells.  2004b.  Disease management in overhead sprinkler and subsurface drip irrigation systems for peanut.  Agron. J.  96:1058-1065.

Lassiter, B.R., D.L. Jordan, G.G. Wilkerson, B.B. Shew, and R.L. Brandenburg.  2016a.  Influence of planting pattern on pest management in Virginia market type peanut (Arachis hypogaea L.).  Peanut Sci. 43:59-66.

Lassiter, B.R., D.L. Jordan, G.G. Wilkerson, B.B. Shew, and R.L. Brandenburg.  2016b.  Influence of cultural and pest management practices on performance of runner, Spanish, and Virginia Market Types in North Carolina.  Advances in Agriculture, Volume 2016, Article ID 5795373.

Lesk, C., Coffel, E., Winter, J., Ray, D., Zscheischler, J., Seneviratne, S. I., & Horton, R. (2021). Stronger temperature-moisture couplings exacerbate the impact of climate warming on global crop yields. Nature Food, 2(9), 683-+.

Lopez, Y., Smith, O.D., Senseman, S.A., and Rooney, W.L., 2001. Genetic factors influencing high oleic acid content in Spanish market‐type peanut cultivars. Crop Sci. 41(1): 51-56.

Mahoney, D.J., D.L. Jordan, R.L. Brandenburg, B.B. Shew, B.R. Royals, M.D. Inman, and A.T. Hare.  2019.  Influence of planting date, fungicide seed treatment, and phorate on peanut in North Carolina.  Peanut Sci.  46:14-21.

Mehl, H.L. 2017. Evaluation of new high oleic Virginia-type peanut cultivars for disease tolerance, yield, and quality. Peanut Science 44:100-110.

Monfort, S., A. Culbreath, M. Abney, R. Brandenburg, B. Royals, D. Jordan, A. Herbert, Jr., S. Taylor, and Sean Malone.  2021.  Effect of thiamethoxam seed treatment on injury from tobacco thrips, incidence of spotted wilt disease, and peanut yield.  J. Crop, Forage, and Turfgrass Management.  Volume 7. doi.org/10.1002/cft2.20135.

Mozingo, R.W., J.C. Wynne, D.M. Porter, T.A. Coffelt, and T.G. Isleib. 1994. Registration of 'VA-C 92R' peanut. Crop Sci. 34(2): 539.

Mozingo, R.W., S. F. O’Keefe, T. H. Sanders, and K. W. Hendrix. 2004. Improving shelf life of roasted and salted inshell peanuts using high oleic fatty acid chemistry. Peanut Sci. 31:40-45.

Mozingo, R.W., T.A. Coffelt, and T.G. Isleib. 2000. Registration of 'VA 98R' peanut. Crop Sci. 40: 1202-1203. 15. Mozingo, R.W., T.A. Coffelt, P.M. Phipps, and D.L. Coker. 2006. Registration of 'CHAMPS' peanut. Crop Sci. 46: 2711-2712.

Mozingo, R.W., T.A. Coffelt, C.W. Swann, and P.M. Phipps. 2004. Registration of 'Wilson' peanut. Crop Sci. 44: 1017-1018.

Mozingo, R.W., T.A. Coffelt, P.M. Phipps, and D.L. Coker. 2006. Registration of 'CHAMPS' peanut. Crop Sci. 46: 2711-2712.

Oakes, J.C., M. Balota, D.L. Jordan, A.T. Hare, and A. Sageghpour.  2020.  Peanut response to seeding density and digging date in the Virginia-Carolina Region.  Peanut Sci.  47:180-188.

Paupiere, M. J., van Heusden, A. W., & Bovy, A. G. (2014). The metabolic basis of pollen thermo-tolerance: perspectives for breeding. Metabolites, 4(4), 889-920.

Prasad, P.V., Craufurd, P.Q. and Summerfield, R.J., 1999. Sensitivity of peanut to timing of heat stress during reproductive development. Crop Science, 39(5), pp.1352-1357.

Prasad, P.V.V., Staggenborg, S.A. and Ristic, Z., 2008. Impacts of drought and/or heat stress on physiological, developmental, growth, and yield processes of crop plants. Response of crops to limited water: Understanding and modeling water stress effects on plant growth processes, 1, pp.301-355.

Price, K., Li, X., Price, A., Chen, C., and Grey, T. 2020. Evaluation of runner-type peanut cultivar tolerance to paraquat tank mixes. Peanut Science 47:103-110.

Ramsey, A. F., Tack, J. B., & Balota, M. (2022). Double or Nothing: Impacts of Warming on Crop Quantity, Quality, and Revenue. Journal of Agricultural and Resource Economics, 47(1), 1-+.

Ramsey, A.F., Tack, J.B., and Balota, M. 2020. Double or nothing: impacts on warming on crop quantity, quality, and revenue.  Journal of Agricultural and Resource Economics 10.22004/ag.econ.307462.

Rowland, D.L., Sorensen, R.B., Butts, C.L., and Faircloth, W.H., 2006. Determination of maturity and degree day indices and their success in predicting peanut maturity. Peanut Sci. 33(2): 125-136.

Sarkar, S. (2021). Development of high-throughput phenotyping methods and evaluation of morphological and physiological characteristics of peanut in a sub-humid environment. Virginia Tech, Doctoral Dissertation.

Sarkar, S., Cazenave, A. B., Oakes, J., McCall, D., Wade, T., Lynn, A., and Balota, M. 2020. High-throughput measurement of peanut canopy height using Digital Surface Models (DSMs). The Plant Phenome J. 3(1): e20003. doi:10.1002/ppj2.20003.

Sarkar, S., Ramsey, A. F., Cazenave, A. B., & Balota, M. (2021). Peanut Leaf Wilting Estimation From RGB Color Indices and Logistic Models. Frontiers in Plant Science, 12.

Shew, B.B., and Beute, M.K. 1984. Effects of crop management of the epidemiology of southern stem rot of peanut. Phytopathology 74:530-535.

Singh, D., Collakova, E., Isleib, T.G., Welbaum, G.E., Tallury, S. and Balota M., 2014. Differential Physiological and Metabolic Responses to Drought Stress of Peanut Cultivars and Breeding Lines. Crop Sci. 54:2262-2274.

Singh, M.P., Erickson, J.E., Boote, K.J., Tillman, B.L., Jones, J.W., and van Bruggen, A.H.C. 2011. Late leaf spot effects on growth, photosynthesis, and yield in peanut cultivars of differing resistance. Agronomy Journal 103:85-91.

Slavík, B., Jarvis, M.S., 1974. Methods of studying plant water relations.

Songsri, P., Jogloy, S., Kesmala, T., Vorasoot, N., Akkasaeng, C., Patanothai, A., & Holbrook, C. C. (2008). Heritability of Drought Resistance Traits and Correlation of Drought Resistance and Agronomic Traits in Peanut. Crop Science, 48(6), 2245-2253.

Srinivasan, R., Abney, M.R., Culbreath, A.K., Kemerait, R.C., Tubbs, R.S., Monfort, W.S., and Pappu, H.R. 2017. Three decades of managing Tomato spotted wilt virus in peanut in southeastern United State. Virus Research 241:203-212.

Tallury, S. P., Isleib, T. G., Copeland, S. C., Anderson, P. R., Balota, M., Singh, D. and Stalker, H. T., 2014.  Registration of two multiple disease-resistant peanut germplasm lines derived from Arachis cardenasii Krapov. & W.C. Gregory, GKP 10017 (PI 262141).  J. Plant Reg. 8:86-89.

Turner, N.C., 1981. Techniques and experimental approaches for the measurement of plant water status. Plant and Soil, 58(1), 339-366.

U.S. Department of Agriculture/National Agricultural Statistics Service. 2022. QuicStats Ad-hoc Tool. Retrieved 8/20/2022 from USDA/NASS QuickStats Ad-hoc Query Tool.

Wilcut, J.W. and S.D. Askew. 1999. Chemical approaches to weed management. In J. R. Ruberson, ed. Handbook of Pest Management. Marcel Dekker: New York, NY: Marcel Dekker. p. 627–661.

Williams, E.J., and J.S. Drexler. 1981. A non-destructive method for determining peanut maturity. Peanut Sci. 8:134-141.

Wynne, J.C., and M.K. Beute. 1983. Registration of 'NC 8C' peanut (Reg. No. 27). Crop Sci. 23: 184.

Wynne, J.C., M.K. Beute, J. Bailey, and R.W. Mozingo. 1991a. Registration of 'NC 10C' peanut. Crop Sci. 31: 484.

Wynne, J.C., R.W. Mozingo, and D.A. Emery. 1979. Registration of ‘NC 7’ peanut (Reg. No. 22). Crop Sci. 19: 563.

Wynne, J.C., R.W. Mozingo, and D.A. Emery. 1986. Registration of 'NC 9' peanut. Crop Sci. 26: 197.

Wynne, J.C., T.A. Coffelt, R.W. Mozingo, and W.F. Anderson. 1991b. Registration of 'NC-V11' peanut. Crop Sci. 31: 484-485.

Attachments

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