VTechWorks Repository :: Browsing by Author "Davis, Paul H."

Browsing by Author "Davis, Paul H."

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2020 Virginia On-Farm Wheat Test Plots
Broaddus, Mike; Clarke, C. Taylor Jr.; Davis, Paul H.; Fimon, Lindy; Henly, Rachel; Jones, Trent; Longest, Robbie; Shuman, Nicole; Stafford, Carl; Romelczyk, Stephanie; Swann, Skyler; Thomason, Wade E. (Virginia Cooperative Extension, 2020-08-19)
Summarizes replicated research and demonstration plots conducted by Virginia Cooperative Extension in cooperation with local producers and agribusinesses.
Characterization of the Mechanism of Resistance of a Johnsongrass (Sorghum halepense) Biotype to Selected Graminicides in Virginia and Response of Mugwort (Artemisia vulgaris) to Specific Herbicidal and Cultural Control Strategies
Bradley, Kevin Wayne (Virginia Tech, 2000-04-26)
Johnsongrass [Sorghum halepense (L.) Pers.] and mugwort (Artemisia vulgaris L.) are both rhizomatous perennial weeds that are capable of rapidly colonizing a variety of different environments. Separate experiments were conducted throughout Virginia from 1996 to 1999 to determine more effective methods for reducing infestations of these perennial weeds in the future. Field and greenhouse experiments conducted on a resistant johnsongrass population discovered in New Kent County, Virginia revealed that this biotype exhibits low levels of resistance to the aryloxyphenoxypropionate (APP) herbicides quizalofop-P and fluazifop-P and the cyclohexanedione (CHD) herbicide sethoxydim. Additional laboratory experiments revealed that resistance is not due to differential absorption, translocation, or metabolism of the APP and CHD herbicides in the resistant vs. the susceptible biotype. However, acetyl-coenzyme A carboxylase (ACCase) assays revealed that resistance to the APP and CHD herbicides is conferred by an overproduction of the ACCase enzyme in the resistant compared to the susceptible johnsongrass biotype. In field experiments conducted on mugwort infestations discovered in several counties throughout Virginia, 100% mugwort control was achieved with standard application rates of picloram at 4 months after treatment (MAT), and also greater than 70% mugwort control was achieved with the higher application rates of clopyralid, glyphosate, and dicamba at 4 MAT. However, all other herbicides evaluated in these experiments provided less than 65% mugwort control at 4 MAT, even at exceptionally high use rates. Additionally, the results from these trials revealed that sequential herbicide applications and sequential mowings prior to herbicide application are both effective mugwort control strategies.
Deep Tillage Prior to No-Till Corn: Research and Recommendations
Thomason, Wade E.; Grisso, Robert D.; Balderson, T. Keith; Davis, Paul H.; Johnson, Sam; Lawrence, Chris; Lewis, Matthew A.; Moore, David M.; Alley, Marcus M. (Virginia Cooperative Extension, 2019-03-29)
Compares cultivation of corn by no-till and deep tillage and notes ways to reduce soil compaction, using deep tillage if soil compaction has effected crop growth and yield.
Deep Tillage Prior to No-Till Corn: Research and Recommendations
Thomason, Wade E.; Grisso, Robert D.; Balderson, T. Keith; Davis, Paul H.; Johnson, Sam; Lawrence, Chris; Lewis, Matthew A.; Moore, David M.; Alley, Marcus M. (Virginia Cooperative Extension, 2009)
Compares cultivation of corn by no-till and deep tillage and notes ways to reduce soil compaction, using deep tillage if soil compaction has effected crop growth and yield.
Evaluation of Urea Ammonium-Nitrate Fertilizer Application Methods
Woodward, Timothy Ryan (Virginia Tech, 2011-05-26)
Increased nitrogen (N) costs and environmental concerns have created a need to reevaluate current sidedress N application recommendations for corn. Injection of Urea Ammonium-Nitrate (UAN) may reduce N-loss via ammonia (NH?) volatilization compared to current surface application methods. This study evaluated injection and surface-banding application techniques of UAN in two ways: (1) by conducting a laboratory experiment where NH?-N loss was measured from UAN applied by both techniques across varying residue covers; and (2) by performing a field study where the application methods were compared by their effect on corn grain yield, ear leaf tissue N content, and stalk nitrate (NO3). The laboratory system used to compare the NH?-N loss from the UAN application methods was evaluated and found to be capable of providing rapid, accurate, and precise measurements of N loss throughout a range of N rates and conditions. In the laboratory study, injection of UAN reduced NH?-N losses to <1% of applied N. Surface-banding of UAN resulted in NH?-N losses between 15.3 and 32.5% of applied N. Results from the field study suggest that differences between application methods were commonly seen in ear leaf tissue N, where injection of UAN was often found to increase tissue N compared to surface-banding. Also, injection of UAN reduced the optimal N rate by 25 kg N ha?? compared to surface-banding. The results suggest that injection of UAN reduces the potential of NH?-N losses and is a practice worth considering in developing an efficient N fertilizer program.
Identification and Control of Honeyvine Milkweed (Ampelamus albidus (Nutt.) Britt.) in Virginia
Bradley, Kevin Wayne; Davis, Paul H.; Hagood, Edward S. (Virginia Cooperative Extension, 2009-05-01)
This publication reviews the identification and control of Honeyvine Milkweed (Ampelamus albidus) in Virginia.
Identification of quantitative trait loci associated with nitrogen use efficiency in winter wheat
Brasier, Kyle G.; Ward, Brian P.; Smith, Jared; Seago, John E.; Oakes, Joseph C.; Balota, Maria; Davis, Paul H.; Fountain, Myron O.; Brown-Guedira, Gina L.; Sneller, Clay H.; Thomason, Wade E.; Griffey, Carl A. (2020-02-24)
Maintaining winter wheat (Triticum aestivum L.) productivity with more efficient nitrogen (N) management will enable growers to increase profitability and reduce the negative environmental impacts associated with nitrogen loss. Wheat breeders would therefore benefit greatly from the identification and application of genetic markers associated with nitrogen use efficiency (NUE). To investigate the genetics underlying N response, two bi-parental mapping populations were developed and grown in four site-seasons under low and high N rates. The populations were derived from a cross between previously identified high NUE parents (VA05W-151 and VA09W-52) and a shared common low NUE parent, 'Yorktown.' The Yorktown x VA05W-151 population was comprised of 136 recombinant inbred lines while the Yorktown x VA09W-52 population was comprised of 138 doubled haploids. Phenotypic data was collected on parental lines and their progeny for 11 N-related traits and genotypes were sequenced using a genotyping-by-sequencing platform to detect more than 3,100 high quality single nucleotide polymorphisms in each population. A total of 130 quantitative trait loci (QTL) were detected on 20 chromosomes, six of which were associated with NUE and N-related traits in multiple testing environments. Two of the six QTL for NUE were associated with known photoperiod (Ppd-D1 on chromosome 2D) and disease resistance (FHB-4A) genes, two were reported in previous investigations, and one QTL, QNue.151-1D, was novel. The NUE QTL on 1D, 6A, 7A, and 7D had LOD scores ranging from 2.63 to 8.33 and explained up to 18.1% of the phenotypic variation. The QTL identified in this study have potential for marker-assisted breeding for NUE traits in soft red winter wheat.
Nitrogen and Phosphorus Fertilization of Corn
Alley, Marcus M.; Martz, Marvin E.; Davis, Paul H.; Hammons, J. L. (Virginia Cooperative Extension, 2009)
Discusses use of nitrogen and phosphorus fertilizers for corn (Zea mays). Discusses placement and amounts of fertilizers to use.
Nitrogen and Phosphorus Fertilization of Corn
Alley, Marcus M.; Martz, Marvin E.; Davis, Paul H.; Hammons, J. L.; Thomason, Wade E. (Virginia Cooperative Extension, 2019-03-20)
Discusses use of nitrogen and phosphorus fertilizers for corn (Zea mays). Also discusses placement and amounts of fertilizers to use.
Nitrogen and Phosphorus Fertilization of Corn
Alley, Marcus M.; Martz, Marvin E.; Davis, Paul H.; Hammons, J. L. (Virginia Cooperative Extension, 2019-01-24)
Discusses use of nitrogen and phosphorus fertilizers for corn (Zea mays). Also discusses placement and amounts of fertilizers to use.
Soybean Rust Incidence and the Response of Soybeans to Foliar Fungicides in 2008
Phipps, Patrick Michael; Stromberg, Erik L.; Rideout, Steven L.; Bush, Elizabeth A.; Holshouser, David L.; Pitman, Robert M.; Taylor, Clark; Estienne, Cynthia Elizabeth; Davis, Paul H.; Wells, Kelvin; Lawrence, Watson (Virginia Cooperative Extension, 2009)
Discusses fungal diseases of soybean plants, and the use of fungicides to control them.
Tips for Profitable Variety Selection: How to Use Data From Different Types of Variety Trials
Thomason, Wade E.; Holshouser, David L.; Balderson, T. Keith; Moore, David M.; Bowen, Eric; Chappell, Glenn F.; Clark, Bobby; Davis, Paul H.; Lawrence, Watson; Parrish, Michael J.; Reiter, Scott; Johnson, Sam; Slade, Glenn; Wells, Kelvin; Yancey, Matthew; Burgess, Keith (Virginia Cooperative Extension, 2019-03-29)
Discusses how to interpret crop variety tests, in terms of variables such as weather, planting date, yield potential in fields, and other data.
Tips for Profitable Variety Selection: How to Use Data From Different Types of Variety Trials
Thomason, Wade E.; Holshouser, David L.; Balderson, T. Keith; Moore, David M.; Bowen, Eric; Chappell, Glenn F.; Clark, Bobby; Davis, Paul H.; Lawrence, Watson; Parrish, Michael J.; Reiter, Scott; Johnson, Sam; Slade, Glenn; Wells, Kelvin; Yancey, Matthew; Burgess, Keith (Virginia Cooperative Extension, 2011)
Discusses how to interpret crop variety tests, in terms of variables such as weather, planting date, yield potential in fields, and others.
Virginia On-Farm Corn Test Plots 2006
Lewis, Matthew A.; Alexander, Wes; Burgess, Keith; Balderson, T. Keith; Chappell, Glenn F.; Davis, Paul H.; Dustin, Robyn; Henley, Philip; Johnson, Sam; Lawrence, Watson; Moore, David M.; Stafford, Carl; Thomason, Wade E. (Virginia Cooperative Extension, 2009-05-01)
Discusses performance trials for commercial corn hybrids, including some genetically modified. Important concerns tested include selection of hybrid varieties, use of herbicides, fungicides and insecticides.
Virginia On-Farm Corn Test Plots, 2007
Lewis, Matthew A.; Burgess, Keith; Balderson, T. Keith; Chappell, Glenn F.; Davis, Paul H.; Johnson, Sam; Lawrence, Watson; Moody, Spencer; Moore, David M.; Parrish, Michael J.; Thomason, Wade E.; Townsend, John (Virginia Cooperative Extension, 2008)
Discusses test data for different cultivars and hybrids of corn, in terms of selection, fertilizer, use of fungicides, drought tolerance, weed removal, nematode control and other concerns.
Virginia On-Farm Corn Test Plots, 2008
Lewis, Matthew A.; Balderson, T. Keith; Chappell, Glenn F.; Davis, Paul H.; Johnson, Sam; Lawrence, Watson; Moore, David M.; O'Berry, Nathan Brook; Parrish, Michael J.; Reiter, Scott; Thomason, Wade E. (Virginia Cooperative Extension, 2008)
Discusses test data for different cultivars and hybrids of corn, in terms of selection, fertilizer, use of fungicides, drought tolerance, weed removal, nematode control and other concerns.
Virginia On-Farm Corn Test Plots, 2009
Lewis, Matthew A.; Balderson, T. Keith; Bowen, Eric; Burgess, Keith; Chappell, Glenn F.; Clark, Bobby; Davis, Paul H.; Jochum, Eric; Johnson, Sam; Lawrence, Watson; Moore, David M.; Parrish, Michael J.; Reiter, Scott; Slade, Glenn; Wells, Kelvin; Thomason, Wade E. (Virginia Cooperative Extension, 2010)
Discusses test data for different cultivars and hybrids of corn, in terms of selection, fertilizer, use of fungicides, drought tolerance, weed removal, nematode control and other concerns.
Virginia On-Farm Soybean Test Plots, 2006
Alexander, Wes; Balderson, T. Keith; Chappell, Glenn F.; Davis, Paul H.; Estienne, Cynthia Elizabeth; Johnson, Sam; Lewis, Matthew A.; Lawrence, Watson; Moore, David M.; Parrish, Michael J.; Slade, Glenn; Stafford, Carl; Wells, Kelvin; Lawrence, Chris; Holshouser, David L. (Virginia Cooperative Extension, 2006)
Discusses data collected from soybean test plots in 2006 including variety selection, fungicides, maturity and development of plants, seed treatments, and tillage systems.
Virginia On-Farm Soybean Test Plots, 2007
Alexander, Wes; Balderson, T. Keith; Chappell, Glenn F.; Davis, Paul H.; Estienne, Cynthia Elizabeth; Johnson, Sam; Lewis, Matthew A.; Lawrence, Watson; Moore, David M.; Parrish, Michael J.; Reiter, Scott; Slade, Glenn; Wells, Kelvin; Holshouser, David L. (Virginia Cooperative Extension, 2007)
Discusses data collected from soybean test plots in 2007 including variety selection, fungicides, maturity and development of plants, seed treatments, and tillage systems.
Virginia On-Farm Soybean Test Plots, 2008
Alexander, Wes; Balderson, T. Keith; Chappell, Glenn F.; Davis, Paul H.; Estienne, Cynthia Elizabeth; Johnson, Sam; Lewis, Matthew A.; Lawrence, Watson; Moore, David M.; Parrish, Michael J.; Reiter, Scott; Slade, Glenn; Wells, Kelvin; Holshouser, David L. (Virginia Cooperative Extension, 2008)
Discusses data collected from soybean test plots in 2008 including variety selection, fungicides, maturity and development of plants, seed treatments, and tillage systems.