bluuebunny/crossref_metadata_2025 huggingface dataset:
Imazethapyr for Broadleaf Weed Control in Peanuts (Arachis hypogaea)
Authors: Wilcut John W. , Walls F. Robert , Horton David N.
Published: April 2010

Field experiments were conducted at the Tidewater Agric. Exp. Station, Suffolk, VA in 1988 and 1989 to evaluate imazethapyr [(±)-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-ethyl-3-pyridine-carboxylic acid]for broadleaf weed control in peanuts (Arachis hypogaea L.). Imazethapyr was applied preplant-incorporated (PPI), preemergence (PRE), at ground-cracking (GC), and postemergence (POT) at rates of 0.036, 0.071, or 0.105 kg ai ha-1. Several sequential imazathapyr systems were also included. The standard of pendimethalin (N-ethylpropyl)-3, 4-dimethyl-2,6-dinitrobenzenamine) PPI, metolachlor(2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide) PRE, and acifluorfen (5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid) plus bentazon (3-(1-methyethyl)-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2, 2-dioxide) POT was included for comparative purposes. Imazethapyr applied either PPI or PRE at 0.071 or 0.105 kg ha-1 provided <90% spurred anoda (Anoda cristata (L.) Schlecht.), control and <96% prickly sida (Sida spinosa L.), control. Eclipta (Eclipta prostrata L.) control was 95% when imazathapyr was applied PRE at 0.105 kg ha-1. Greater than 90% annual morningglory (Ipomoea spp.) control was only achieved with imazethapyr applied PPI or PRE at 0.105 kg ha-1. The standard provided complete control of eclipta, and 51%, 92%, and 94% control of spurred anoda (Anoda cristata (L.) Schlecht.), prickly sida (Sida spinosa L.), and annual morningglories, respectively. Several imazethapyr systems yielded equivalent to the standard. Averaged across all rates, imazathapyr applied PPI yielded 4110 kg ha-1, PRE = 3860 kg ha-1, GC = 3680 kg ha-1, and POT = 3370 kg ha-1. Several imazethapyr systems provided net returns equivalent to the standard. Corn grown the following year was not injured by any imazethapyr treatment to peanuts the previous year.
Efficacy and Economics of Common Bermudagrass (Cynodon dactylon) Control in Peanut (Arachis hypogaea)
Authors: Wilcut John W.
Published: April 2010

Field experiments were conducted in 1988 and 1989 to evaluate various postemergence graminicides for common bermudagrass (Cynodon dactylon (L). Pers.) control in peanuts (Arachis hypogaea). A single application of fluazifop-P [(R)-2-[4[[5-(trifluorornethyl)-2-pyridinyl]oxy]phenoxy]propanoic acid] or clethodim [(E, E)-(±)-2-[1-[[(3-chloro-2-propenyl)oxy]imino] propyl]-5-[2-ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one] controlled approximately 25 to 30% more common bermudagrass than a single application of sethoxydim (2-[1-(ethoxyimino) butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one) or quizalofop [(±)-2-[4[(6-chloro-2-quinoxalinyl)oxy]phenoxy]propanoic acid]. Two graminicide applications were required for greater than 90% common bermudagrass control. Treatments which provided greater than 90% control included two applications of sethoxydim (0.31 followed by (fb) 0.31 kg ha-1 or 0.31 fb 0.16 kg ha-1), fluazifop-P (0.21 fb 0.21 kg ha-1) or 0.21 fb 0.11 kg ha-1), and clethodim (0.28 fb 0.28 kg ha-1). These same treatments provided complete common bermudagrass control when evaluated the following summer. Peanut yield and net return from a single graminicide application generally were not improved with two applications.
Variability Associated with Determining Grade Factors and Support Price of Farmers Stock Peanuts1
Authors: Whitaker Thomas B. , Dickens James W. , Giesbrecht Francis G.
Published: April 2010

Replicated grade samples were taken from runner, Spanish, and virginia-type farmers stock peanut lots. Each sample was graded according to the procedures of the Federal State Inspection Service. The variability of % foreign material (%FM) and % loose shelled kernels (%LSK) associated with a 1800-g sample was measured. The variability of % sound mature kernels (%SMK), % sound splits (%SS), % other kernels (%OK), % damage (%DAM), and % extra large kernels (%ELK) associated with a 500-g sample was also measured. The variance was shown to be a function of the magnitude of the grade determination and was described by a relationship derived from binomial theory. From the measured grade factors, the support price per gross ton was calculated for each grade sample using the 1988 USDA loan schedule. The variance of the price per gross ton was also estimated and appeared to be independent of the price per gross ton. The coefficients of variation averaged across all lots tested were 21.1, 18.7, 2.6, 21.2, 14.0, 55.3, 7.8, and 2.4% for %FM, %LSK, %SMK, %SS, %OK, %DAM, %ELK, and price per gross ton, respectively. The computed price per gross ton of a farmers lot that has a true value of $600 was estimated to vary from $573 to $627 95% of the time when using the 500 and 1800 g grade sample to measure each grade factor.
Accuracy and Feasibility of Determining Single Peanut Kernel Moisture Content1
Authors: Dowell F. E. , Lamb M. C.
Published: April 2010

The accuracy of a single peanut kernel moisture meter (SKM) was determined on peanuts with moisture contents (mc) from 4 to 50%. Results indicated a significant difference between calibration curves determined over the 4–12% mc range and the 4–50% mc range. No mechanical failures of the SKM occurred; however, excess residue build-up on the SKM rollers affected the moisture meter accuracy. Correlation coefficients for average and single kernel moisture calibration equations were 0.88 and 0.91, respectively, for field cured peanuts over the range of 4 to 12% mc. Procedures for integrating the SKM into the present farmers stock grading process are discussed.
Digging Date and Conservational Tillage Influence on Peanut Production1
Authors: Wright F. S. , Porter D. M.
Published: April 2010

The influence of conservational tillage and date of digging on pod yield, crop value, and grade factors were evaluated as a means to increase the production efficiency of peanuts. Two conservational tillage systems, in-row and band tillage, and one conventional tillage system were compared over 3 yr. The Florigiant cultivar was planted in immature wheat killed with glyphosate (Roundup) or clean tilled soil. Peanuts were dug 8 to 11 d before and after the medium (normal) digging date of 141 DAP. Pod yields averaged 19% less and crop values averaged 25% less for the conservational tillage systems as compared to the conventional tillage system. Digging 8 to 11 d early reduced yield 15% and value 21%; whereas, digging 8 to 9 d late reduced yield 6% and value 5% as compared to the medium digging date. The early digging date significantly decreased the grade factors of extra-large kernels (ELK), sound mature kernels (SMK), and total meat content (TM). Tillage systems did not have a consistent effect on grade factors over the 3-yr period. Results from this study indicate that yield and value for the Florigiant cultivar were significantly less under conservational tillage as compared to conventional tillage.
Early Leafspot of Peanuts: Effect of Conservational Tillage Practices on Disease Development1
Authors: Porter D. M. , Wright F. S.
Published: April 2010

The effects of tillage systems on the incidence and severity of early leafspot of peanut (Arachis hypogaea L.) caused by Cercospora arachidicola were determined in three peanut cultivars during a four-year field study. Conventional and conservational tillage systems were utilized. In the conventional system, the land was tilled with a moldboard plow to a depth of approximately 25 cm, disked, and peanut seed were planted in soil with minimum plant residue. In the conservational system the existing winter cover crop, wheat (Triticum aestivum L.), was killed with a herbicide. Two methods of seedbed preparation were used (in-row tillage and band-tillage) in the conservational tillage systems. A 25-cm wide band was tilled with a modified rotary tiller in the band-tilled plots. In the in-row tilled plots, seed were planted directly into the killed winter wheat residue with minimal soil preparation. At the end of the growing season, leafspot incidence and severity were significantly less in 1984 and 1986 than in 1985 and 1987. Leaflet infection, precentage defoliation, and lesions per leaflet were significantly greater in conventional tilled plots than in band-tilled or in-row tilled plots. Disease incidence and severity were similar in band-tilled and in-row tilled plots. Pod yields were greater in conventional tilled plots than in band-tilled or in-row tilled plots.
Effects of Various Postemergence Herbicide Treatments and Tobacco Thrips (Frankliniella fusca) Injury on Peanut Yields in Virginia1
Authors: Herbert D. A. , Wilcut J. W. , Swann C. W.
Published: April 2010

A two-year field study was conducted in Virginia to determine the combined effects of earlyseason injury caused by certain postemergence-applied herbicides and tobacco thrips, Frankliniella fusca (Hinds), feeding on cv. NC7, virginia-type peanuts. Treatments included combinations of aldicarb, applied as granules in-furrow at planting, and carbaryl, paraquat, acifluorfen, and pyridate applied postemergence. Main stem height, canopy width, tobacco thrips injury, pod weight, and value were measured. Paraquat and acifluorfen treatments significantly reduced main stem height and canopy width compared with pyridate. Thrips injured approximately 40 to 50% of untreated plant leaves. Aldicarb significantly reduced thrips injury to less than 17%. Combined early-season herbicide and thrips significantly reduced peanut main stem height and canopy width compared with plants that were protected from thrips and not subjected to herbicide stress, and differences remained apparent as late as 59 days after treatment, 79 days after planting. Although injured plants achieved normal foliar growth by harvest time, pod weight and value were significantly reduced.
Use of Pinolene or Other Spray Adjuvants with Iprodione for Improved Control of Sclerotinia Blight on Peanut1
Authors: Smith F. D. , Phipps P. M. , Stipes R. J.
Published: April 2010

Various spray adjuvants were evaluated in 1985 and 1986 with iprodione (Rovral®) for improved control of Sclerotinia blight of peanut, caused by Sclerotinia minor (Jagger) Kohn. Treatments were applied three times on demand, using high-volume nozzles to deliver 335 L/ha or low-volume nozzles to deliver 140 L/ha. Acetic acid, Buffer P.S.®, Chem Wert Plus®, hydrochloric acid, pinolene (Nu-Film-17®), SoyOil 937® and Spray-Aide® were tested with iprodione in 1985, and ChemWett Plus®, pinolene and Spray-Aide® were chosen for additional trials in 1986. Treatments of iprodione at 1.12 kg/ha with pinolene at 0.42% in low-volume sprays and 0.18% (v/v) in high-volume sprays produced the greatest yield of peanut during both years. Additional testing of iprodione with pinolene used only high-volume sprays, and these treatments were applied on demand: three times in 1987 and twice in 1988, 1989 and 1990. Yield and value of peanut over the 6-yr period of high-volume treatments were increased significantly (P = 0.05) by iprodione with pinolene, compared to iprodione alone. The addition of pinolene increased the mean yield by 348 kg/ha and value of peanut by $291/ha. The cost of using pinolene as an adjuvant averaged $6.95/ha each year. Disease incidence was 12% lower in plots treated with iprodione and pinolene, compared to iprodione alone, but this difference was not significant over the period.
Evaluation of a Bulk Drying Model for Peanuts1
Authors: Parti M. , Young J. H.
Published: April 2010

Results of a peanut bulk drying model, PEADRY8, have been compared with experimental test results for Virginia-type peanuts. The model describes the peanut pod as two separate components with moisture movement in both liquid and vapor form. The Henderson equation was used to describe the equilibrium moisture contents of the kernel and the hull. The following conclusions were drawn: (1) predicted drying times averaged 11% longer than the observed values; (2) predicted kernel moisture contents at the top of the wagons averaged 5% less than the measured values; (3) predicted hull moisture contents at the top of the wagons averaged 17% higher than the observed values; (4) predicted hull final moisture contents at the top of the wagons average 21% higher than measured values and (5) predicted exhaust air temperatures averaged 1% higher than measured values.

An attempt was made to improve the fit of the observed and simulated results by changing the equation to describe the equilibrium moisture contents. The Chung-Pfost equation, compared to the Henderson equation, was more accurate in describing the hull moisture content and less accurate in describing the kernel moisture content history. Changing the reference air flow rate of the thin-layer drying relationship did not give a better fit between the observed and predicted data.

Several drying simulations were found to be very sensitive to small changes in either wet-bulb or dry-bulb temperature. Small errors in wet-bulb temperature measurement could account for the predicted drying times for six experiments which were excessively long relative to observed values.
Resistance to Sclerotinia Blight and Early Leafspot in Chinese Peanut Germplasm1
Authors: Porter D. M. , Coffelt T. A. , Wright F. S. , Mozingo R. W.
Published: April 2010

Sclerotinia minor, causal agent of Sclerotinia blight, and Cercospora arachidicola, causal agent of early leafspot, are two of the most important pathogens of peanut (Arachis hypogaea L.) in Virginia and North Carolina. Twenty-two Chinese peanut germplasm lines were screened to identify resistance to these two pathogens, and evaluated for agronomic characteristics including seed size, testa color, and pod yield. Germplasm lines with PI numbers 476824 and 476843 exhibited more resistance to S. minor than other Chinese plant introductions, or the U.S. cultivars Florigiant and VA 81B. PI 476823 and PI 476837 were most resistant to C. arachidicola. Resistance to one pathogen was often associated with high levels of susceptibility to the other pathogen. Resistance to S. minor was also associated with undesirable characteristics for large-seeded virginia-type peanuts such as tan testa color and small seed size.
Variation in Yield and Resistance to Southern Stem Rot Among Peanut (Arachis hypogaea L.) Lines Selected for Pythium Pod Rot Resistance1
Authors: Grichar W. James , Smith O. D.
Published: April 2010

Five Spanish and seven runner peanut (Arachis hypogaea L.) genotypes and five check cultivars were compared for southern blight susceptibility on heavily Sclerotium rolfsii-infested soil. Inoculum density of S. rolfsii at the test site was enhanced by continuous years of residue management. The genotypes derived from crosses with PI 365553 and PI 475871 were selected based on reaction to Pythium pod rot and agronomic performance. Variation for southern blight incidence occurred among lines in both runner and Spanish genotypes. Disease incidence was lower in four runner genotypes, Southern Runner, and TxAG-3 than in Okrun and Florunner. Significantly (p=.05) less disease occurred in one breeding line, Tx855138, than in other Spanish entries. Three-year average yields of runner genotypes ranged to 25% higher than runner cultivars, while Tx855138 averaged 50% higher in yield than Tamnut 74. Over entries, the coefficients of correlation for yield and southern blight incidence, and southern blight incidence and disease discolored pods were not statistically significant.
Comparison of Fluorescence Sorting and Color Sorting for the Removal of Aflatoxin from Large Groups of Peanuts
Authors: Pelletier M. J. , Reizner J. R.
Published: April 2010

Fluorescence sorting (by both machine and hand) and color sorting (by both machine and hand) are compared as methods for reducing aflatoxin levels in groups of peanuts. An experimental design is used that allows the four methods to be compared quantitatively. Approximately 1200 photographs of peanut groups were taken, allowing for a more complete understanding of the visual characteristics of contaminated peanuts. Sampling errors are controlled by the experimental design and by including a large fraction of the peanuts in aflatoxin assays. Fluorescence sorting was not effective as an aflatoxin control method. Machine color sorting was shown to be effective in the removal of aflatoxin-contaminated peanuts. Hand sorting was shown to be even more effective than machine color sorting in aflatoxin removal.
Progress and Variability After Four Cycles of Recurrent Selection in Peanut1
Authors: Halward T. , Wynne J. C.
Published: April 2010

Recurrent selection procedures are becoming more popular as a means of population improvement in self-pollinated crops. Four cycles of recurrent selection for yield in a broad-based peanut (Arachis hypogaea L.) population have been completed. The objectives of this study were to determine (a) progress made after four cycles of recurrent selection for fruit yield and (b) if sufficient variability remained in the population to permit further improvements in yield from additional cycles of selection. The 40 highest yielding lines from 100 random-paired matings, were intercrossed to produce each successive cycle, resulting in a selection intensity of 40%. Bulked seed of the parental lines from each cycle were evaluated for yield to determine progress made after four cycles of selection. The observed variation in yield among entries was mainly due to differences among cycle means. Differences among cycle means were also detected for pod length, but not for any of the other fruit traits measured. The response to selection for yield was linear with a significant (p = 0.01) and positive regression coefficient (b = 190.7 kg ha-1). Selection based on fruit yield did not significantly change the means for any of the fruit traits measured. Significant estimates of genetic variability among entries within the cycle 4 population for yield and all fruit traits measured suggest that continued progress from additional cycles of selection should be expected in this population. Greater progress from selection may have resulted had a higher selection intensity been applied. However, estimates of genetic variability would be expected to decrease with each cycle of selection as the selection intensity increases and as the genetic base of the original population narrows. In the use of a broad-based population and a relatively low selection intensity, we chose to accept a lower rate of progress/cycle for yield in order to maintain a greater level of genetic variability within the recurrent selection population.
Inheritance of Resistance to Sclerotinia minor in Selected Spanish Peanut Crosses1
Authors: Wildman L. G. , Smith O. D. , Simpson C. E. , Taber R. A.
Published: April 2010

TxAG-5, a sclerotinia resistant Spanish germplasm line released jointly by the Texas Agricultural Experiment Station, USDA, and the Oklahoma Agricultural Experiment Station, was crossed in reciprocal to two Spanish lines, Tx851856 and Sn73–30. Parent, F1, F2, BC1F1, and F3 populations were evaluated under high natural inoculum for resistance to Sclerotinia minor using a disease rating scale of 1 (no disease) to 5 (severely diseased), and the number of days from first appearance of the fungus until plant death was recorded. F2:3 families were compared for disease the following year for genotypic assessment of the F2 parents. F1 generation plants of the Sn73–30 cross were susceptible, but F1 plants from Tx851856 were intermediate. Some TxAG-5 succumbed to the disease. F2 distributions were continuous. F2 genotypic frequency distributions based on F3 and BC1F3 families were near continuous. Broadsense heritability estimates for disease ratings for TxAG5/Tx851856 and TxAG-5/Sn73–30 were 14 and 23%, respectively. Narrowsense heritabilities based on parent offspring regression of F3 families on F2 plants were 11% for Tx851856/TxAG-5 and 1% for Sn73–30/TxAG-5. Selection for resistance among the F2 plants to increase the frequency of resistant F3 families would have been ineffective.
Feeding-Site Preference of Fall Armyworm, Corn Earworm, and Granulate Cutworm (Lepidoptera:Noctuidae) on Florunner Peanut1
Authors: Deitz S. S. , Chapin J. W. , Adler P. H.
Published: April 2010

The feeding-site preferences of fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), corn earworm (CEW), Helicoverpa zea (Boddie), and granulate cutworm (GCW), Agrotis subterranea (F.) were studied on excised laterals and entire plants of Florunner peanut. Six larval size classes, based on head-capsule widths, were distinguished for FAW and GCW, and five for CEW. FAW and CEW larvae had very similar feeding behaviors. Both species fed primarily on the terminal three leaves of peanut laterals, but this preference for young foliage declined with larval age. All FAW and CEW size classes fed on blooms, with greatest incidence (21% of feeding observations) occurring in the second through fourth size classes. Axillary-bud feeding by FAW and CEW was greatest (23 and 17% of feeding observation, respectively) in the third size class. The last two larval size classes of FAW and CEW spent 20% of feeding time on R2 pegs. GCW fed primarily on blooms through the first four size classes. Foliage feeding by GCW remained ≤10% of feeding observations until the fifth size class. GCW did not feed on axillary buds in whole plant studies. Peg feeding by GCW peaked in the fourth and fifth size classes (36% of feeding observations). On whole plants, each FAW consumed 4.8 ± 1.2 tetrafoliate leaves, severed 6.3 ± 1.6 pegs, and damaged an additional 3.6 ± 1.7 pegs. Each CEW consumed 4.7 ± 0.8 leaves, severed 7.1 ± 1.6 pegs, and damaged 2.4 ± 1.4 pegs. Each GCW consumed 3.9 ± 0.5 leaves, severed 8.5 ± 2.0 pegs, and damaged 3.5 ± 1.3 pegs.
Lipid Oxidation of Edible Peanut Pastes during Storage with Variation of Environmental and Processing Factors1,2
Authors: Agbo Onah Francis , Anderson John C. , Singh Bharat
Published: April 2010

Storage studies were performed for a period of 127 days to evaluate factors of processing and storage environments affecting rancidity development of peanut paste. Factors of milling (stone slab or plate-type attrition mill), ethylenediaminetetraacetic acid (none or with 100 ppm EDTA additions), oxygen (vacuum or atmospheric packaging), light (dark or fluorescent illumination) and temperature (4C or 45C) were incorporated into a 2(5–1) fractional-factorial design. Rancidity developments were monitored using thiobarbituric acid reactive substances (TBARS) number and peroxide values. Initially dominant, the positive effect of oxygen on peroxidation was subsequently outpaced by the effect of temperature. Throughout the study, the effect of temperature on peroxidation levels was consistently positive and statistically significant. Significant positive interactions of the two effects continued from the second week to the end of the first month and a late appearance of negative interactions between light and temperature were noted. Elevated levels of TBARS were shown after 8 weeks without consistent association to the particular design factors.
Pollen Germination of Rhizoma Peanut cv. Florigraze1
Authors: Niles W. L. , Quesenberry K. H.
Published: April 2010

Assessing pollen germination is fundamental to investigating infertility in plants. A potential cause of poor seed production in Florigraze (Arachis glabrata Benth.), rhizomatous peanut, was investigated by incubating pollen on in vitro germination media. The optimum sucrose and boron concentrations for pollen germination was delineated in a series of factorial experiments. Pollen germinability was assessed four times during the growing season. Flowers were collected at 2 h intervals spanning 30 h of development from bud to wilted flower. The optimum sucrose concentration was 100 g kg-1 but there were no differences in germination for B concentrations between 50 and 1,000 mg kg-1. Up to 78% pollen germination was obtained in a solution consisting of 100 g kg-1 sucrose, 100 mg kg-1 H3BO3, 250 mg kg-1 Ca(NO3)2·4H2O, 200 mg kg-1 MgSO4·7H2O and 100 mg kg-1 KNO3 in deionized water. Repeatable estimates of germinability were obtained in incubations of less than 30 min at 35 C. Florigraze pollen collected from developing buds as early as 2200 h the night before anthesis germinated in vitro. Peak germination extended from 2400 h to 1200 h the morning of anthesis. Under cool, dry conditions, the pollen collected 2 d after anthesis remained germinable. These results suggested poor pollen germinability was not the basis of low seed production in rhizomatous peanut. Pollen with high in vitro germination can dependably be collected from Florigraze flowers throughout the growing season during the first 6 h following anthesis, usually between sunrise to noon.
Response Of Eight Genetically Diverse Peanut Genotypes To Chlorimuron1,2
Authors: Johnson W. Carroll , Holbrook C. Corley , Mullinix Benjamin G. , Cardina John
Published: April 2010

Field studies were conducted in 1988 and 1989 to compare the sensitivity of eight genetically diverse peanut (Arachis hypogaea L.) genotypes to early applications of chlorimuron. A split-plot experimental design was used to allow comparison between treated and nontreated peanut for each genotype. Chlorimuron (0.009 kg ai ha-1) was applied 30 and 37 days after emergence in 1988 and 1989, respectively, to Florunner, Tifrun, Tifton 8, GA-207–3–4, New Mexico Valencia A, New Mexico Valencia C, Tamnut 74, and Pronto peanut. Chlorimuron reduced the percentage of total sound mature kernels when averaged across all genotypes, but was not specific to genotype. Chlorimuron reduced the weight of 100 kernels of Tifrun, Tifton 8, and New Mexico Valencia C in both years. The unit values of GA-207–3–4 and New Mexico Valencia C were significantly reduced both years by early applications of chlorimuron. Yields of Tifrun, Tifton 8, and GA-207–3–4 were reduced both years. Gross returns, which reflect effects on grade, unit value, and yield, were reduced by early applications of chlorimuron for Tifton 8 and GA-207–3–4 in both years. Based on these results, Tifrun, Tifton 8, GA-207–3–4, and New Mexico Valencia C are more inherently sensitive to chlorimuron than the other genotypes.
Sample Size Effects on Measuring Grade and Dollar Value of Farmers' Stock Peanuts1
Authors: Dowell F. E.
Published: April 2010

Multiple samples of two sizes from 40 trailers of farmers' stock peanuts were inspected to determine sample size effects on measuring grade factors and dollar value. Grade factors and dollar value were measured using the current sample size (IX) and in a sample double the current size (2X). The 2X sample variances for determining sound mature kernels, sound splits, other kernels, damaged kernels, foreign material, loose shelled kernels, and load value were significantly lower than the IX sample variances in only 8 or less of the 40 trailers. Average dollar values indicate measurement errors caused by equipment and human errors when cleaning samples, determining kernel size, and determining damaged kernels may be increasing as sample size increases. At least 24% of the total error can be attributed to equipment and human error. The grade factors with the smallest percentage of total error attributable to equipment and human error will benefit most by increasing sample size. Thus, dollar value, sound mature kernel, foreign material and damaged kernel measurements will benefit most by increasing sample size; whereas, loose shelled kernels, sound split and other kernel measurements will benefit most by improving equipment and procedures.
In Vitro Culture of Arachis hypogaea Peg Tips1
Authors: Rau Tallury P. S. , Stalker H. T. , Pattee H. E. , Reece P.
Published: April 2010

Arachis hypogaea L. cv. NC 4 was used as a model plant system in an effort to develop an in vitro embryo rescue protocol which could have application to interspecific hybrid embryos, which often abort at very early growth stages. Embryo growth and development was studied in 1- to 4-day-old peg tips containing proembryos equivalent to a stage where many interspecific hybrid embryos abort. Three independent experiments were conducted to 1) determine the most favorable basal media, 2) evaluate the effects of auxins and cytokinins on growth, and 3) determine a favorable combination of auxins and cytokinins for in vitro peanut embryo growth. The results indicated that MS (Murashige and Skoog) medium with 3% sucrose was the most favorable basal medium among seven media and two sucrose concentrations analyzed. IAA (indole-3-acetic acid) at 1.5 mg L-1 in combination with a range of KN (kinetin) levels from 0.5 to 1.25 mg L-1 were the growth regulator combinations of choice. Proembryo growth reached the multicellular globular stage, but differentiation into heart-shaped embryos did not occur.
In Vitro Regeneration of Valencia-type Peanut (Arachis hypogaea L.) from Cultured Petiolules, Epicotyl Sections and Other Seedling Explants1
Authors: Cheng Ming , Hsi David C. H. , Phillips Gregory C.
Published: April 2010

This study evaluated plant development via direct organogenesis from in vitro-cultured young seedling tissues of cultivated peanut, especially the valencia-type peanut. Complete plants were regenerated from in vitro-cultured petiolule-with-blade-attached explants, leaflet segments, and epicotyl andpetiole sections. Multiple shoots arose on Murashige and Skoog medium (MS) supplemented with 6-benzylaminopurine (BA) (5–25 mg/L) plus 1-naphthaleneacetic acid (NAA) (0.5–3 mg/L). After 30 d culture on 25 mg/L BA + 1 mg/L NAA, 1.6 buds or shoots/explant were regenerated from the petiolule-with-blade-attached explants. Comparable numbers of shoots were obtained from epicotyl sections of the first node region of the seedling after 60 d culture using 10 mg/L BA + 1 mg/L NAA. Leaflet segments and petiole sections were less responsive for shoot formation. Excised shoots developed roots in vitro upon transfer for 15 d to MS medium supplemented with NAA at 1 mg/L. Plantlets were transferred to soil and grown in a greenhouse to maturity. A wide range of cultivated peanut genotypes was evaluated for organogenic responsiveness, using the petiolule-with-blade-attached explant source. Only valencia-type cultivars, or a hybrid derivative with a Valencia background, were responsive with this regeneration system.
Effects of Rapeseed Meal Soil Amendments on Microsclerotia of Cylindrocladium crotalariae in Naturally-Infested Soil1
Authors: Adamsen F. J. , Porter D. M. , Auld D. L.
Published: April 2010

Cylindrocladium black rot (CBR) of peanut, caused by Cylindrocladium crotalariae, is most often controlled through the use of metham sodium (Vapam), a commercial soil fumigant. Several plant species, including rape, produce glucosinolates which decompose to form isothiocyanates which are closely related to methyl isothiocyanate the active ingredient of metham sodium. Such plants may be useful in CBR control strategies. This research was conducted to determine the fungicidal effect of the glucosinolate in rapeseed meal on microsclerotia of C. crotalariae. Rapeseed meal containing 13 mmol of glucosinolate kg-1 was added to a soil column 50 mm in diameter and 325 mm long. Meal was either placed at the 150 mm depth or mixed with the top 150 mm of soil. An untreated control and metham sodium at a rate equivalent to 190 L ha-1 injected 150 mm deep were included. Metham sodium was much more effective in reducing microsclerotial populations of C. crotalariae than rapeseed meal. However, the amount of glucosinolate in the metham sodium treatment was three times as great as that found in the rapeseed meal. Rapeseed meal treatments usually significantly reduced the number of soilborne microsclerotia when comparisons were made with untreated soil.
Survey of Wireworms (Coleoptera: Elateridae) in Virginia and North Carolina Peanut Fields1
Authors: Herbert D. A. , Brandenburg R. L. , Day E. R.
Published: April 2010

Sixty peanut (Arachis hypogaea L.) fields were surveyed for wireworms (Coleoptera: Elateridae) in the Virginia-North Carolina peanut area in 1989 and 1990. A series of baited container soil traps was placed in each field once in early June and again in early August for a total of 605 trap-weeks (trap per field per week = 1 trap-week)). Trap capture was similarly low in both states and in both years with a total of 59 wireworm specimens collected: an average of one wireworm per field per year. Species composition was similarly diverse with Conoderus vespertinus F. comprising 58 percent, C. lividus De Geer 20 percent, Glyphonx sp. 8 percent, Melanotus communis Gyllenhal 7 percent, C. sp. 5 percent, and C. bellus Say 2 percent. Even though wireworm captures were low, moderate to high levels of pod damage were observed. The large number of southern corn rootworm (Diabrotica undecimpunctata howardi Barber) adults detected on nearby pheromone baited sticky traps indicated that most pod damage was not by wireworm but by southern corn rootworm. Implications are that although several wireworm species can be found in association with peanut, they appear to play only a minor role in peanut pod damage in the survey area.
Leaf Nitrogen Content, Photosynthesis and Radiation Use Efficiency in Peanut1
Authors: Sinclair T. R. , Bennett J. M. , Boote K. J.
Published: April 2010

It has been hypothesized that a close correlation exists between specific leaf nitrogen content (SLN, g N m-2 leaf area) and leaf carbon exchange rate (CER), and crop radiation use efficiency (RUE). This association has not been investigated previously in peanut (Arachis hypogaea L.) so the objective of this research was to obtain such data under greenhouse and field conditions. In the greenhouse study differing nitrogen fertilizer treatments for a non-nodulated cultivar resulted in leaves with a wide range of SLN and CER. A strong, positive association between SLN and CER was found. In the field little variation in either SLN or CER was observed through much of the growing season in four commercial cultivars. Consistent with the observation of stability in SLN and CER, RUE based on total, intercepted solar radiation was found to be constant at 1.00 g MJ-1 through the growing season. However, the observed RUE was 29% greater than a theoretical RUE calculated assuming a uniform distribution of SLN in the canopy. One possibility is that RUE of peanuts may be enhanced by a nonuniform SLN distribution within its leaf canopy. In any event, the results of both the greenhouse and field tests showed that peanut CO2 assimilation is closely linked to leaf SLN.
Weighing Platforms for Automated Peanut Curing1
Authors: Vellidis G. , Allgood M. E. , Perry C. D. , Allison J. M. , Kvien C. S.
Published: April 2010

An instrumented weighing platform was developed for in-process moisture determination of curing peanuts and a field study was conducted to evaluate its performance. The design and evaluation of the weighing platform are described in detail. Statistical analysis of the difference between the final moisture content predicted by the platform and the actual kernel moisture content of cured peanuts indicated that the weighing platform accurately predicted final kernel moisture content. The weighing platform system can easily be incorporated into existing curing facilities. It has the potential to reduce the number of samples required by conventional curing techniques and, by maintaining better moisture content control reduce the incidence of overcuring or undercuring.
Activity of Fosthiazate against Meloidogyne arenaria, Frankliniella spp., and Sclerotium rolfsii in peanut1
Authors: Minton N. A. , Brenneman T. B. , Bondari K. , Harrison G. W.
Published: April 2010

The efficacy of fosthiazate, a new organophosphorus compound, against the peanut root-knot nematode (Meloidogyne arenaria (Neal) Chitwood), thrips (Frankliniella spp.), and southern stem rot (Sclerotium rolfsii Sacc.) in peanut (Arachis hypogaea L.) was studied for 2 years at Tifton, Georgia. Different rates and methods of applying granular and emulsifiable concentrate formulations of fosthiazate were compared with rates and methods of applying granular fenamiphos and aldicarb which were included as standard treatments. When compared with untreated controls, all treatments of all compounds increased peanut yield and reduced nematode galls on peanut roots, pods, and pegs and thrips damage to foliage significantly in both years. The treatments, however, varied in their effects on southern stem rot. Peanut yields from plots treated with equal rates of the granular and emulsifiable concentrate formulations of fosthiazate were similar. Yields of plots treated with fosthiazate at different rates compared favorably with those treated with comparable rates of fenamiphos and aldicarb. Fosthiazate increased peanut yield as much as 214% in 1990 and 64% in 1991, but yields varied with rates applied.
A Rapid Non-Destructive Technique for Fatty Acid Determination in Individual Peanut Seed1
Authors: Zeile W. L. , Knauft D. A. , Kelly C. B.
Published: April 2010

Modification of fatty acid composition can improve the keeping quality of peanut oil and may expand markets for peanut usage. Modification may involve hybridization to recombine existing genes, or the creation of new variability through mutagenesis or transformation with genes from other organisms. Identification of the fatty acid composition of individual seed could improve the chances of obtaining peanut genotypes with desired fatty acid composition. Published techniques for fatty acid analysis of individual peanut seed require the use of approximately half the cotyledonary seed tissue and utilize a process of solvent extraction and esterification. We have used a procedure that requires a small fraction of seed tissue and analyzes fatty acids through direct transmethylation.

Comparisons were made between procedures using seven genotypes representing a wide range of fatty acid composition variability. Quantities of fatty acids with C<20 were not statistically different between tests. While some differences were observed in longer-chained fatty acids (C≥20), the relative values among genotypes were similar. This procedure maintains greater integrity of the seed for planting purposes, requires less time and cost for fatty acid analysis, and can improve efficiency of individual seed analysis.
Peanut Quality Improvement Through Controlled Curing1
Authors: Baker K. D. , Cundiff J. S. , Wright F. S.
Published: April 2010

Peanut curing must proceed fast enough to avoid mold problems and harvest delays, and yet proceed slow enough to avoid milling quality loss. A new dryer heat control method, termed drying rate control (DRC), was developed to better meet the above criteria. DRC was tested and compared with humidistat control (HC) and conventional control (CC) using a bulk simulation model and laboratory curing tests. Airflow rates of 5, 10, and 15 m3/min/m3 were used. Simulation studies incorporated five years of actual weather data from Suffolk, Va. Laboratory curing tests were done on nine lots of peanuts over two years. Average curing times were the same for CC and DRC, but averaged 17% longer with HC. Estimated fuel costs were nearly the same for CC and DRC, but were 14% less for HC. Mold risk, percent splits in the grade sample, and volatile organic matter concentrations were nearly the same for all heater control methods. Percent skin slippage in ELKs, measured with a subjective test, averaged approximately 30% less with DRC and HC as compared to CC. In summary, HC resulted in better peanut quality than CC with lower fuel cost, but increased curing time. DRC resulted in better peanut quality than CC with similar curing time and similar fuel cost.
A Note On Broad-Sense Heritability of Selected Sensory Descriptors in Virginia-Type Arachis Hypogaea L.1
Authors: Pattee Harold E. , Giesbrecht Francis G. , Mozingo R. Walton
Published: April 2010

Improvement of flavor quality is a breeding objective that merits increased attention. To obtain further information on broad-sense heritability of selected sensory attributes, 30 virginia-type genotypes sources were grown in replicated experiments at two locations during 1988 for evaluation. Roasted peanut paste samples were evaluated for 14 sensory attributes. Fruity attribute was confirmed as having a significant suppressive effect on roasted peanut attribute. Session-to-session variation was significant and use of an incomplete block design provided for control of panel variation in the experimental error. Broad-sense heritability estimates for roasted peanut, sweet, and nutty sensory attributes were higher than previously reported, 0.31 vs. 0.24; 0.68 vs. 0.14; 0.37 vs. 0.05, respectively. Nine genotypes were found to have statistically significant higher roasted peanut intensity than the industry accepted standard Florigiant. Further calculations showed that experiments with two replications at each of four locations should have an 80% chance of detecting statistical significance for roasted peanut attribute differences of 0.5 units among genotypes when testing at the 5% level. A similar experiment with two replications at two locations should have a 40% chance of detecting statistical significance.
Calcium Source and Time of Application For Runner and Virginia Peanuts1
Authors: Gascho G. J. , Hodges S. C. , Alva A. K. , Csinos A. S. , Mullinix B. G.
Published: April 2010

Sandy soils of the southern coastal plain are commonly deficient in Ca in the upper 8 cm; this limits development of high yielding and high quality peanut (Arachis hypogaea L.). Calcium is often leached by rainfall and irrigation from such soils and is not available for the development of pods. Previous studies have shown that gypsum applied at bloom is effective for supplying Ca and increasing yield and grade when Mehlich 1 soil Ca in less than 200 to 250 mg kg-1 for runner-type peanut, and is nearly always effective for virginia-type peanut. Field experiments were conducted over 3 years to compare preplant incorporated limestone and gypsum application at bloom for both runner- and virginia-types. Preplant incorporated limestone was effective for reducing pod rot and for increasing pod yield, SMK, and value ha-1 for runner peanut in experiments conducted on sandy soils with pH less than 6.2 and with Mehlich 1 extractable Ca less than 200 mg kg-1. Application of Ca was not effective when extractable Ca was greater than 200 mg kg-1. Calcitic and dolomitic limestones were both effective for the runner-type. Limestone was also an effective source for virginia peanut. However, in our studies conducted on sands, the least pod rot and the greatest yield, grade, and value of virginia peanut were only attained when bloom gypsum was applied. Preplant incorporated gypsum was not as effective as bloom gypsum for either type of peanut.
Flavor, Color and Texture of Peanuts Treated with Hydrogen Peroxide1
Authors: Clavero Ma R. S. , Hung Y-C. , Beuchat L. R. , Nakayama T.
Published: April 2010

Treatment of aflatoxin-contaminated peanut kernels in 0.075% hydrogen peroxide for 1 min has been proposed to reduce aflatoxin contamination by 90%. The effect of hydrogen peroxide treatment on the flavor quality, texture and color was, therefore, investigated. Two hundred grams of peanuts were submerged in a solution containing 0, 0.075 or 0.225% hydrogen peroxide for 1 and 3 min. Treated peanuts were dried to 8-9% moisture, blanched and stored in plastic bags for 0, 1, 2 and 3 weeks at 39 C. Peak areas identified as hexanal increased with increasing hydrogen peroxide concentration, regardless of the treatment and storage time. No significant differences in peak areas identified as ethanol were observed after a 3-week storage time, regardless of the concentration of hydrogen peroxide and treatment time. Hydrogen peroxide treatment and storage of treated peanuts did not significantly affect the lightness (L), chroma (C) and texture of the treated peanuts. Furthermore, sensory analysis conducted on peanut brittle prepared from raw peanuts and peanuts treated with 0.075% hydrogen peroxide for 1 min showed no significant difference between the two samples evaluated.
Evaluation of Biological Nitrogen Fixation Capacity in Arachis Species and the Possible Role of Polyploidy1
Authors: Stalker H. T. , Nickum M. L. , Wynne J. C. , Elkan G. H. , Schneeweis T. J.
Published: April 2010

Arachis species have potential for enhancing cultivated peanut (Arachis hypogaea L.) germplasm as forages and cover crops. This study's objective was to evaluate a range of Arachis species for biological nitrogen fixation capacity. Several Arachis species are tetraploids, and it has been shown that tetraploidy may play an important role in nodule initiation. Species were first tested under natural field conditions and then in the greenhouse using three Bradyrhizobium strains that had been previously shown to be effective on peanut. Nodule number, nodule weight, nitrogenase activity determined by acetylene reduction, and shoot dry weight were measured as indicators of nitrogen fixation capacity. In the field, tetraploid species produced significantly more nodules than the diploids, but total dry matter accumulation was independent of the number of nodules or rate of fixation. In the greenhouse, no significant differences were observed among the bradyrhizobial strains. Arachis hypogaea and A. monticola showed significantly higher measures of nitrogen fixation capacity for all measured traits than the diploid species. However, autotetraploid plants of A. villosa did not have significantly more nodules than diploids of the same accession; the autotetraploids consistently had higher nitrogenase activity. Arachis pusilla never formed a symbiotic relationship with the bradyrhizobial strains used.
Use of F6285 for Weed Control in Peanut: Efficacy and Crop Injury1,2
Authors: Johnson W. Carroll , Mullinix Benjamin G.
Published: April 2010

Field studies in 1991 and 1992 at Tifton and Attapulgus, GA evaluated the weed control efficacy and crop safety of F6285 on peanut. Treated peanut were stunted by F6285 and had chlorotic leaflet margins. The degree and persistence of injury varied according to rate of F6285. The lowest rate of F6285 (0.14 kg ai ha-1) produced the aforementioned symptoms early in the season, but peanut recovered by late season with no yield effects (P≤0.05). F6285 at 0.28 and 0.42 kg ha-1 severely injured peanut and reduced yields. Preemergence and vegetative emergence applications of F6285 were equally injurious. F6285 effectively controlled yellow nutsedge at rates as low as 0.14 kg ha-1, but sicklepod was not controlled at rates up to 0.42 kg ha-1. F6285 controlled yellow nutsedge more effectively that standard treatments of metolachlor or imazethapyr, but crop injury from F6285 was greater (P≤0.05) than from other herbicides.
Relationship of Pod Damage by Southern Corn Rootworm and Soil Drainage to Peanut Yield
Authors: Ang B. N. , Herbert D. A. , Mack T. P. , Hodges R. L.
Published: April 2010

No published studies have quantified the relationship between damage to peanut (Arachis hypogaea L.) pods by the southern corn rootworm, Diabrotica undecimpunctata howardi Barber, and yield. Peanut yields have generally been found to be inconsistently related to control measures (insecticide treatments) used for southern corn rootworm. This discrepancy may be caused by the variable survival of eggs and larvae in soils with different moisture retention capacities. This study determined the relationship of pod damage and the influence of soil drainage to peanut yield. Eleven on-farm tests for management of southern corn rootworm, conducted between 1989 to 1991 and involving 48 different control measures, were compiled for analysis. All experimental fields were classified into three drainage classes: moderately well drained, somewhat poorly drained and poorly drained. Yield declined with an increase in percentage pod damage (P < 0.05). Percentage of mature pods damaged increased with increased area poorly drained. Stepwise regression models indicated that the inherent drainage properties of a field and proportion of pod damage observed, by themselves, can explain 45% of the variance observed in yield regardless of insecticide treatment.