bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Host Genotype on Incubation Period, Receptivity, Lesion Diameter, and Leaf Area Damage of Didymella arachidicola on Peanut1
Authors: Subrahmanyam P. , Smith D. H. 
Published: April 2010

Abstract
The effect of host genotype on incubation period, receptivity, lesion diameter and leaf area damage of Didymella arachidicola on nine peanut (Arachis hypogaea L.) genotypes was investigated under monocyclic infection in the glasshouse. The genotypes, Florunner. P 84/5/256, C 347/5/6, C 346/5/8 and P 105/3/7, resistant to the pathogen in field trials, had a longer incubation period, reduced receptivity, lesion diameter, and percentage leaf area damage, than susceptible genotypes. Among the susceptible genotypes, Tamnut 74 had the shortest incubation period, and highest receptivity, the largest lesion diameter, and percentage leaf area damage. The other susceptible genotypes. Egret, 38/7/20, and P 84/5/112, were intermediate for these variables. Production of pycnidia and pseudothecia of the pathogen could not be demonstrated in infected leaf tissues of any of the genotypes studied. There was significant interaction between plant age and disease development. Younger plants had a shorter incubation period, higher receptivity, larger lesion diameter, and percentage leaf area damage than older plants. Correlation coefficients among incubation period, receptivity, lesion diameter, and leaf area damage were highly significant. The possible role of these variables in disease epidemics and their use in glasshouse screening of peanut germplasm for resistance to D. arachidicola are discussed.
Equipment and Procedures to Measure Peanut Headspace Volatiles1
Authors: Dickens J. W. , Slate A. B. , Pattee H. E. 
Published: April 2010

Abstract
An electronic meter was developed to measure the concentration of organic volatiles in the headspace over samples of comminuted peanuts. The meter consists of a commercially available semiconductor (Taguchi) and a temperature compensation circuit. The conductivity of the sensor increases in the presence of organic volatiles. Calibration of the meter can be made by measuring the volatiles in the headspace over known concentrations of ethyl alcohol in water. Good agreement between meter measurement of the concentration of organic volatiles in the headspace over samples of comminuted peanuts and the percent of freeze-damaged peanuts in the samples was demonstrated. Other tests with peanuts which were cured at 50 C or exposed to −1 C before curing demonstrated the meter can detect these types of objectionable flavors and indicated meter readings were not significantly affected by the moisture content of the peanuts.
The Effect of Loose-Shelled Kernels and Foreign Material on Pirimiphos-Methyl Residues in Stored Farmers Stock Peanuts1
Authors: Arthur F. H. , Redlinger L. M. , Simonaitis R. A. 
Published: April 2010

Abstract
Farmers stock peanuts containing either 0% loose-shelled kernels (LSK) and 0% foreign material (FM), 5% LSK-10% FM, or 10% LSK-20% FM were sprayed with 20 PPM pirimiphos-methyl. Peanut samples were analyzed for insecticide residues during a 1-year storage period. Significantly lower residues were found on in-shell peanuts with 0% LSK-FM than on either of the 2 LSK-FM combinations. Insecticide residues accumulated in the FM and to a lesser extent in the LSK. Negligible residues were found on sound mature kernels from solid pods.
Density of the Lesser Cornstalk Borer, Elasmopalpus lignosellus (Zeller) in Peanut Fields: Endemic and Outbreak Population Configurations
Authors: Mack T. P. , Backman C. B. 
Published: April 2010

Abstract
The population growth of Elasmopalpus lignosellus (Zeller), the lesser cornstalk borer (Insecta: Lepidoptera: Pyralidae), was determined in conventionally tilled Florunner peanut fields in endemic (1983–1985) and outbreak (1986) population configurations. The density of E. lignosellus eggs, larvae, and pupae was estimated by weekly soil flotation and by soil sieving. Adult density and abundance was estimated with pheromone traps, emergence cages, and flush samples.
In the endemic years, low levels of eggs, larvae, pupae, and adults occurred throughout the growing season. Adult populations exhibited 1–2 weak peaks per growing season. The outbreak year was characterized by an exponential increase in E. lignosellus eggs, larvae, pupae, and adults.
A regression relationship was developed from the 1983–1986 data that relates the weekly mean number of E. lignosellus larvae per meter determined by soil sieving to the total rainfall (cm) and the number of hot (≥35 C daily maximum temperature) days in the previous 30 days. This is a predictive tool that can be used to time sampling to predict possible larval population increases before extensive damage occurs.
Colonization of sclerotia of Sclerotinia minor by a potential biocontrol agent, Penicillium citrinum1
Authors: Akem C. N. , Melouk H. A. 
Published: April 2010

Abstract
Sclerotia of Sclerotinia minor were soaked in a conidial suspension (1.3 × 107 conidia/mL) of Penicillium citrinum at 25 ± 2 C for 1 h. This resulted in coating each sclerotium with about 3.7 × 104 conidia. Treated sclerotia were incubated either in the dark on dry or damp Whatman No. 1 filter paper or in pasteurized and nonpasteurized soil at 25 ± 2 C, for up to eight weeks. Colonization by P. citrinum of sclerotia incubated on damp or dry filter paper was 70 and 25%, respectively. Seventy four percent of sclerotia incubated in pasteurized soil were colonized and destroyed by P. citrinum, whereas 55% colonization and destruction occurred in sclerotia incubated in a nonpasteurized soil. Similarly treated sclerotia of Sclerotinia sclerotiorum variety major and Sclerotium rolfsii were incubated in pasteurized soil and colonized by P. citrinum at 45 and 5%, respectively, over the same period of time. Up to 50% colonization and destruction by P. citrinum has been observed on sclerotia of S. minor recovered from soil in a peanut field in Oklahoma. These findings suggest a potential use of P. citrinum as a biocontrol agent for S. minor.
Embryo Rescue in Wide Crosses in Arachis. 3. In vitro Culture of Peg Tips of A. hypogaea Selfs and Interspecific Hybrids1
Authors: Moss J. P. , Stalker H. T. 
Published: April 2010

Abstract
Embryo rescue in wide crosses in Arachis has only been achieved from culturing ovules excised from well developed pods, or from immature pods derived from flowers treated with gibberellic acid (GA) and which had embryos large enough to dissect without injury. The objective of this study was to determine whether reproductive tissues could grow in vitro without the need to dissect them from the peg tip and to determine the effects of GA application on flowers at the time of pollination, age of peg when cultured, and the presence of the peg meristem on reproductive growth, callus production, and peg elongation in vitro. Pegs elongated in culture only when the peg meristem was not removed. Ovules enlarged and grew out of the surrounding peg tissue in 3.8 to 32.8% of the cultures. Significantly more ovules grew when the peg meristem was removed (p &lt; 0.01) and when 10- and 20- day-old pegs were cultured (p &lt; 0.05). Overall, the most successful treatment for growth of ovules was treating flowers with GA at pollination and culturing without the peg meristem 10 days after pollination when 25.0 and 32.8% of all hybrid and selfed ovules, respectively, grew. Embryo growth was observed in an average of 8.4 and 17.6% of embryo sacs in hybrid and self peg tips, respectively, with several embryos reaching the globular stage after 21 days in vitro. This illustrates the potential for culturing young reproductive tissues of Arachis to recover interspecific hybrids.
Economic Assessment of Herbicide Systems for Minimum-Tillage Peanuts1
Authors: Wilcut John W. , Wehtje Glenn R. , Colvin Daniel L. , Patterson Michael G. 
Published: April 2010

Abstract
Field experiments were conducted in 1983 and 1984 on a Dothan loamy sand at Headland, AL to evaluate herbicide systems for minimum tillage peanut (Arachia hypogaea L. Florunner) production. The influence of minimum tillage-herbicide systems on weed control, peanut yield, market grade, and net returns were examined. Two minimum tillage-herbicide systems provided greater yield and higher net returns with equivalent control of Texas panicum (Panicum texanum Buckle.) and Florida beggarweed [Desmodium tortuosum (SW.)DC] as compared to a conventional tillage-herbicide system. One of these systems included oryzalin [4-(dipropylamino)-3, 5-dinitrobenzenesulfonamide] and paraquat (1, 1′-dimethyl-4,4′bipyridinium ion) applied preemergence followed by an early postemergence application of acetochlor [2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl)acetamide] and dinoseb [2-(1-methylpropyl)-4,6-dinitrophenol] and a postemergence-directed application of cyanazine (2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpropanenitrile). The other system included benefin [N-butyl-N-ethyl-2,6-dinitro-4-(trifluoromethyl)benzenamine] and metolachlor (2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2)methoxy-1-methylethyl)acetamide) applied preplant-incorporated within-the-row followed by an early postemergence application of dinoseb and ethalfluralin [N-ethyl-N-)2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl) benzenamine] and a postemergence-directed application of paraquat. Herbicide inputs for these two minimum tillage-herbicide systems were greater than for the conventional tillage-herbicide system.
Inheritance of Late Leafspot Resistance and Agronomic Traits in Peanut1
Authors: Jogloy S. , Wynne J. C. , Beute M. K. 
Published: April 2010

Abstract
Twenty peanut (Arachis hypogaea L.) populations in F2 generation from an M x N mating design involving five late leafspot (Cercosporidium personatum)-resistant female parents and four adapted male parents were evaluated for late leafspot resistance with a detached leaf culture technique. Agronomic traits were evaluated in the field. Objectives were 1) to identify the best parent for agronomic traits and the best source of resistance to late leafspot, 2) determine the correlations among components of resistance, 3) determine the correlations of resistance and agronomic traits, and 4) estimate heritability of late leafspot resistance. General combining ability was highly significant for agronomic traits and for most measurements of late leafspot resistance. Specific combining ability was significant for pod length and seed size. Of the male parents, NC 6 and NC 7 produced the best progenies for both agronomic traits and late leafspot resistance. Components of resistance to late leafspot among resistant female parents were not significantly different. NC 17090 produced the best progenies for pod yield and seed yield. NC 17135 produced progenies with good agronomic traits. Correlations among components of resistance to late leafspot indicated that lines with increased latent period, decreased lesion number, lesion size and defoliation, and reduced spore production can be selected. However, high yielding plants tended to be susceptible to late leafspot. Broadsense heritability for components of resistance was low to moderate (0.13–0.68). Narrow-sense heritability for parameters of resistance was consistently low (0.0–0.128). Selection for late leafspot resistance in the F2 populations was not effective.
Comparison of Soil Insecticides Alone and In Combination With PCNB for Suppression of Southern Stem Rot of Peanut1
Authors: Hagan A. K. , Weeks J. R. , McGuire J. A. 
Published: April 2010

Abstract
The soil insecticides, chlorpyrifos 15G (2.2 kg a.i./ha), ethoprop 15G (3.3 kg a.i./ha), and fonofos (2.2 kg a.i./ha) were compared with pentachloronitrobenzene (PCNB) 10G (11.2 kg a.i./ha) and PCNB (11.2 kg a.i./ha) + insecticide combinations for suppression of southern stem rot caused by Sclerotium rolfsii on peanut in a series of field trials in 1985, 1986, and 1987 in southeastern Alabama. Stem rot loci counts were reduced each year by chlorpyrifos and two of three years of ethoprop, and fonofos compared to the non-treated control. Disease suppression with chlorpyrifos and ethoprop was similar all three years and two of three years with fonofos to that with the fungicide PCNB. Significant differences (P = 0.05) in yield were noted only in 1986 between each of the soil insecticides and the non-treated control. PCNB and PCNB + insecticide combinations with the exception of PCNB + ethoprop in 1985 significantly increased yields over the non-treated control each year. PCNB + insecticide combinations generally provided better disease suppression and/or yield response than each insecticide but not PCNB applied alone. When data were pooled for all 3 years, all treatments significantly reduced disease incidence and significantly increased yield except fonofos and ethoprop.
Dry Matter Accumulation and Nutrient Uptake of High-Yielding Peanut (Arachis Hypogaea L.) Grown in a Sandy Soil1
Authors: Halevy J. , Hartzook A. 
Published: April 2010

Abstract
Growth and NPK uptake of peanut of cultivar Shulamit (Arachis hypogaea L.) grown in a sandy soil (Xeropsamment - Torripsamment) was investigated under favorable semi-arid conditions conducive to high yields. The rate of dry matter production was slow until flowering at 44 days after planting when only 6% of the total dry matter had been produced. From flowering until 111 days. 58% of the total dry matter was produced with an average rate of 97 kg DM ha-1 day-1. Thereafter, from 112 days until 128 days, at the pod ripening stage, the rate was 233 kg DM ha-1 day-1. Total dry matter production was 11,200 kg ha-1, of which 54% was in the leaves and stems and 46% in the pods. The pod dry matter yield was 5200 kg ha-1. The total uptake of N and P followed generally that of dry matter production, whereas highest K uptake occurred at 128 days and then decreased by 26% at harvest time. The total uptake of N, P, and K was 300, 27 and 244 kg ha-1, respectively. At 128 days the N, P, and K in the pods was 63, 71, and 16% of the total uptake of N, P, and K, respectively.
Chlorpyrifos-methyl as a Protectant of Farmers Stock Peanuts1
Authors: Arthur F. H. , Redlinger L. M. , Simonaitis R. A. 
Published: April 2010

Abstract
Runner variety farmers stock peanuts were treated with either distilled water, 52 ppm malathion. or chlorpyrifosmethyl (CM) applied at 10, 15, 20 and 25 ppm, held in a metal shed and artificially infested with insect pest species commonly found in stored peanuts. Peanuts were sampled at 2, 4, 6, 9 and 12 months post-treatment. After 6 months ca 22% of loose-shelled kernels (LSK) in malathion-treated peanuts were damaged by insects; after 9 and 12 months damage increased to 36 and 49%. In contrast, LSK damage in peanuts treated with CM exceeded 6% after 9 and 12 months only in the 10 ppm treatment. Damage to kernels from cracked pods in malathion-treated peanuts was 6.9 and 11.2% after 9 and 12 months, respectively, but damaged cracked pod kernels exceeded 2% only in the 10 ppm CM treatment at 12 months. Degradation of CM residues occurred more slowly than malathion residues during the final 6 months of the test.
Peanut Cultivar Response to Tillage Systems1
Authors: Colvin D. L. , Brecke B. J. 
Published: April 2010

Abstract
Field experiments were conducted during 1984 and 1985 at Williston, Florida on a Zuber loamy sand (fine, mixed hyperthermic Ultic Hapludalfs) and at Jay, Florida in 1985 on a Red Bay sandy loam (fine-loamy, siliceous, thermic Rhodic Paleudults) to investigate the effects of conventional and minimum tillage on the grade and yield of eight peanut (Arachis hypogaea L.) cultivars. Cultivars studied included: 1) three runner-type peanuts - Florunner. Sunrunner, and GK-7, 2) four virginia-type peanuts - Early Bunch, Florigiant, GK-3, and NC-7, and 3) one spanish-type peanut - Valencia C. Conventional plots were established using a moldboard plow with repeated diskings to provide a smooth even seedbed. Minimum-tillage plots were established using a modified Brown-Harden Ro-Till®. Tillage did not affect peanut yield, and cultivars generally did not differ in response to tillage systems. There appears to be no immediate need for peanut cultivar performance testing in different tillage systems. However, in 1984 at Williston Florunner and Sunrunner yielded 20% and 12% better, respectively, in conventional tillage conditions than in minimum-tillage, whereas in 1985 Early Bunch yielded 17% less in tilled systems compared to minimum-tillage systems. This response may be related to slight plant density differences, harvestability problems or genotypic differences. Results indicate that yield and quality of peanuts, based on the data collected from the cultivars utilized in this study would be equal under conventional or minimum-tillage production.
Tillage Variables for Peanut Production
Authors: Colvin D. L. , Brecke B. J. , Whitty E. B. 
Published: April 2010

Abstract
Effects of minimum tillage (MT) production techniques on peanut (Arachis hypogaea L.) root growth and yield were unknown. Field experiments were therefore conducted during 1984 near Williston and Marianna, FL and during 1985 near Williston and Jay, FL to evaluate effects of surface and subsurface tillage on peanut production. Soil types were a Zuber loamy sand (fine, mixed hyperthermic Ultic Hapludalf) at Williston, a Chipola sandy loam (loamy, siliceous, thermic Arenic Hapludult) at Marianna, and a Red Bay sandy loam (fine, loamy, siliceous, thermic Rhodic Paleudult) at Jay. The Sunrunner peanut cultivar was planted using a modified twin 23 cm row spacing and seeded at a rate of 140 kg/ha. Eight tillage systems that included combinations of conventional tillage, strip-tillage, and no-tillage with and without subsoiling or subsurface slitting were evaluated. Peanuts germinated and grew well except in no-tillage plots that received no subsurface tillage. Without surface or subsurface tillage there was not sufficient soil disturbance to insure proper seed-soil contact or seed cover. Generally, plots that received some degree of conventional tillage yielded better than plots with no surface preparation (4090 vs. 3760 kg/ha avg.). Minimum tillage plots yielded numerically less than conventional plots but in only a few cases were significant differences in yield noted. At most locations, minimum tillage plots that received no subsurface tillage developed a “lazy root syndrome” in which the few roots produced were quite shallow and grew near the soil surface. These treatments yielded less (3680 vs. 4010 kg/ha avg.) than those with conventional seedbed preparation or the minimum tillage treatments receiving subsurface tillage. Root strength and penetration measurements roughly reflect the same trends as peanut yields. The slit-tillage system resulted in peanut yields equal to or better than those obtained with chisel point subsoiling. Slitter wear and breakage problems were encountered but overall, the subsurface slit system appears to be a functional alternative to chisel point subsoiling.
Ovule and Embryo Culture of Arachis hypogaea and Interspecific Hybrids1
Authors: Stalker H. T. , Eweda M. A. 
Published: April 2010

Abstract
Interspecific hybridization in Arachis is difficult between species within sectional groups and nearly impossible among more distantly related species. Embryos usually abort early in the reproductive cycle; thus in vitro techniques are necessary to recover many desirable hybrid combinations in the genus. The objectives of this investigation were to develop techniques whereby mature plants could be recovered from otherwise aborting embryos. First, ovule culture was performed using eight genotypes, three levels of kinetin, and the two basal media Murashige and Skoog (MS) and N6. Two-tenths mg/L kinetin in media resulted in 24% of the ovules swelling to a size of 3-4 mm which could be used for excising embryos. Embryo culture was next performed on five genotypes. The transfer series (I) 0.2 mg/L kinetin for 21 days, (2) 0.5 mg/L 6-benzylamino-purine (BAP) for 14 days and, (3) MS without growth regulators resulted in 34.6% of ovules producing plants across genotypes; other transfer series either resulted in a lower percentage of plant recovery and/or tissues of some genotypes which did not survive to maturity. The BAP medium induced shoot growth, while root growth was induced on the MS without growth regulator medium. Approximately 90% of embryos transferred to a mist system after 7-9 weeks in vitro survived transplanting to soil. Two interspecific hybrids were recovered from incompatible hexaploid x diploid crosses, but only after roots were induced using a MS basal medium with 4 mg/L 1-naphthaleneacetic acid:2 mg/L indole-3-butyric acid in a fourth tissue transfer. The experiments illustrated the feasibility of rescuing embryos of A. hypogaea and interspecific peanut hybrids. The process is slow and will be most applicable to wide crosses which cannot be obtained by more conventional methods.
A Rapid Method for Evaluating Genotype Resistance, Fungicide Activity, and Isolate Pathogenicity of Sclerotinia minor in Peanut.1
Authors: Brenneman T. B. , Phipps P. M. , Stipes R. J. 
Published: April 2010

Abstract
Peanut stem segments 8.5-cm long were inoculated at leaf nodes with mycelial plugs of Sclerotinia minor and incubated in moist chambers at 20 C. Water-soaked lesions were often visible after 24 hr. The rate of lesion elongation was used to quantitatively assess the physiological resistance of peanut genotypes to Sclerotinia blight, screen chemicals for fungicidal activity, and evaluate the pathogenicity of S. minor isolates. The age and/or developmental state of lateral limbs of plants had a marked effect on lesion development; 3 days after inoculation, mean lesion lengths were 58.8, 46.8, and 38.9 mm for terminal, median and basal parts of stems, respectively. The speed, simplicity and adaptability of this method make it a valuable tool for research on Sclerotinia blight of peanut.
Relative Tolerance of Peanuts to Alachlor and Metolachlor1
Authors: Wehtje Glenn , Wilcut John W. , Hicks T. Vint , McGuire John 
Published: April 2010

Abstract
Field studies were conducted during 1984, 1985, and 1987 to evaluate weed control and the relative tolerance of peanuts (Arachis hypogaea) to alachlor and metolachlor when applied at rates from 2.2 to 13.4 kg ai/ha. Both single and split preemergence, and postemergence applications were included. In 1984 and 1985, neither herbicide adversely affected yields compared to a hand-weeded control. In 1987, metolachlor at a rate of 9.0 kg/ha and alachlor at 13.4 kg/ha reduced yields. Across all years, at least a two-fold safety factor existed between the maximum registered rate and the rate necessary for peanut injury. Occurrence of injury appears to be related to rainfall. Metolachlor was slightly more mobile than alachlor in soil chromatography trials, which may be a factor in its slightly greater propensity to be injurious under certain conditions of extensive leaching and/or slow peanut emergence.
Comparison of Visual, Enzyme-Linked Immunosorbent Assay Screening, and HPLC Methods in Detecting Aflatoxin in Farmers Stock Peanut Grade Samples
Authors: Cole R. J. , Dorner J. W. , Kirksey J. W. , Dowell F. E. 
Published: April 2010

Abstract
Grade samples from 152 lots of farmers stock peanuts were analyzed for aflatoxin by both an Enzyme-Linked Immunosorbent Assay (ELISA) rapid screening test and high performance liquid chromatography (HPLC). Results from HPLC and ELISA were compared to the results of the visual inspection method used by the Federal State Inspection Service (FSIS). The results showed 41% of the grade samples with visible Aspergillus flavus (Segregation 3) contained less than 20 ppb aflatoxin when analyzed by both ELISA and HPLC methods; 18.7% of Segregation 1 peanuts actually contained aflatoxin with a range of 26-2542 ppb. The results of ELISA and HPLC agreed in 98.6% of the composite lot analyses with the detection of 20 ppb or greater. However, the ELISA rapid screening test failed to give positive tests 12 of 13 times when the aflatoxin content was between 20-43 ppb in the component samples.