bluuebunny/crossref_metadata_2025_split huggingface dataset:
Corn Growth and Yield as Affected by Surface and Subsoil Compaction
Authors: Voorhees W. B. , Johnson J. F. , Randall G. W. , Nelson W. W. 
Published: July 2010

AbstractWheel traffic of harvesting operations on agricultural fields often carries compactive loads in excess of 8 Mg. Consequently, soil physical properties may be affected to depths of 60 cm, and these effects of compaction may persist for a number of years. In addition, smaller compactive forces that affect only the surface layer of soil are applied annually during spring tillage and planting operations. A replicated field study was conducted on a Webster clay loam (fine‐loamy, mixed, mesic Typic Haplaquolls) in southern Minnesota, and two Ves clay loams (fine‐loamy, mixed, mesic Udic Haplustolls) in southwestern Minnesota to assess the effects of surface and subsoil compaction on the growth and yield of corn (Zea mays L.). A total of six compaction treatments was imposed; subsoil compaction of control (no subsoil compaction), 9 Mg per axle, and 18 Mg per axle loads, each with and without annually applied interrow surface compaction of <4.5 Mg per axle. During the first year after high axle loading, 9 and 18 Mg per axle loads significantly decreased final grain yield by 9 and 30%, respectively, on the Webster soil. For the second year, the 18 Mg per axle treatment significantly reduced yield by 12% as compared with the control treatment. Soil water loss data indicated a more shallow rooting depth and/or reduced root activity in the 18 Mg per axle treatment. High axle loads on a dry Ves soil caused little subsoil compaction; grain yield was reduced by only 6% the first year after high axle loading. High axle loads on a relatively wet Ves soil compacted the soil to a depth of 60 cm. However, relatively dry climatic conditions the following year negated any potential adverse effects of subsoil compaction and yields were not affected. Surface layer compaction from annual interrow wheel traffic did not cause a significant yield response consistently at any site.
Nitrate Reductase Activity and Nitrate Concentration in Cotton Plant Leaf Blades and Petioles
Authors: Chu Chang‐chi , Graham Lucy E. , Bariola Louis A. 
Published: July 2010

AbstractGreenhouse studies were conducted to determine the potential of nitrate reductase activity (NRA) as an indicator of the change of N concentration of cotton (Gossypium hirsutum L.) shoots. The results showed that cotton petiole in vivo NRA was not significantly different from NRA in leaf blades during vegetative growth. Nitrate reductase activity (in vivo) in cotton petioles was significantly higher than in leaf blades during reproductive growth. When plants were in the three‐mature‐leaf stage, petiole NRA contributed 16% of total cotton shoot NRA. The petiole biomass was 14% of total shoot fresh weight and 8% of total shoot dry weight. Petiole NRA of plants in the vegetative growth stage increased from 39 to 68 pmol NO−2 g1− FW (fresh weight) s−1 when supplemented with nitrate‐N. These results indicate that cotton petiole NRA is significant and its assay has potential for incorporation into monitoring systems that determine the change of N concentration in cotton shoots.
Herbicide × Annual Fertility Programs Influence on Creeping Bentgrass Performance
Authors: Johnson B. J. 
Published: July 2010

AbstractCreeping bentgrass (Agrostis palustris Huds.) is increasing in the use of golf greens in the upper South where heat and drought stress occurs. Research was initiated to determine the effects of annual fertilizer programs on performance of creeping bentgrass treated with spring and fall‐applied herbicides. Treatments were arranged in a split‐split block with subunits in strips. Fertilizer programs were the main block and the blocks were stripped by spring and fall herbicide treatments. Soil type was an artificial rootzone mix. Creeping bentgrass performed best the first 26 wk of each year when fertilized at the high (490‐20‐195 kg NPK ha−1 yr−1) fertility level and best the last 26 wk of each year when fertilized at the medium (294‐12‐124 kg NPK ha−1 yr−1) fertility level. The quality of creeping bentgrass fertilized annually at the low (98‐6‐52 kg NPK ha−1 yr−1) fertility level was unacceptable. The quality of creeping bentgrass was reduced less at the medium fertility level than at the low fertility level when treated with oxadiazon {3‐[2,4‐dichloro‐5‐(1‐methylethoxy)phenyl]‐5‐(1,1‐dimethylethyl)‐1,3,4‐oxadiazol‐2‐(3H)‐one} and bensulide {O,O‐bis(1‐methylethyl)‐S‐[2‐[(phenylsulfonyl)amino]ethyl]phosphorodithioate} + oxadiazon. Ethofumesate [(±)‐2‐ethoxy‐2,3‐dihydro‐3,3‐dimethyl‐5‐benzofuranyl methane‐sulfonate] applied in the fall 1986 maintained the highest quality ratings at the high fertility level until mid‐April when the quality was the same whether fertilized at the medium or high level. In most instances in 1987, the quality of creeping bentgrass treated with ethofumesate at the medium fertility level was equally as good as when treated with the same herbicide but at the high fertility level. When fertilizer by herbicide interaction occurred, creeping bentgrass maintained a higher quality at the medium to high fertility level than at the low fertility level.
Fall‐Seeded Legume Cover Crops for No‐Tillage Corn in the Humid East
Authors: Holderbaum J. F. , Decker A. M. , Messinger J. J. , Mulford F. R. , Vough L. R. 
Published: July 2010

AbstractNo‐tillage systems utilizing winter cover crops can reduce erosion and leaching losses. Fall‐seeded legumes can also supply significant amounts of N to subsequent corn (Zea mays L.) crops. The suitability of 14 fall‐seeded legumes, three small grains and four legume/grass mixtures was evaluated for winter covers from 1982 through 1985 on Matapeake silt loam (fine‐loamy, mixed, mesic, Typic Hapludult) and Mattapex silt loam(fine‐silty, mixed mesic, Aqualfic Normuldult) Coastal Plain soils as well as Delanco silt loam and Chester silt loam (fine‐loamy, mixed, mesic, Aquic Hapludult) Piedmont soils. Hairy vetch (Vicia villosa Roth), crimson clover (Trifolium incarnatum L.) and Austrian winter peas [Pisum sativum (L.) Poir.] were the most promising cover crops. Fall growth and early soil coverage was highest with crimson and lowest with vetch which had higher winter survival and spring growth. Peas and, to a lesser extent, crimson clover stands were damaged in some years by Sclerotinia trifoliorum Eriks. In some years top growth of vetch contained up to 350 kg N/ha. While N concentration varied among species, total N production was determined more by dry matter yield. Legume cover crops had a greater influence on corn grain yields on the heavier textured soils and longer growing season of the Coastal Plain. In 1985, N contribution to the subsequent corn crop was reduced when small grains were seeded with annual legumes. Results from these studies show that winter annual legumes can reduce N costs while providing better soil protection during winter months.
Cupric Ion as a Tracer to Measure Spray Application Efficiency
Authors: Nichols R. L. , Gaines T. P. , Stephenson M. G. 
Published: July 2010

AbstractThe uniformity and efficiency of agricultural chemical spray solutions on plants, such as sucker control chemicals on tobacco (Nicotiana tabacum L.), needs to be determined. This study was conducted to determine if cupric ion could be used as a tracer to measure the spray applicaton efficiency of a tobacco sucker control chemical. Chlorpropham (1‐methylethyl 3‐chlorophenylcarbamate) was amended with 1.92 mmol of cupric sulfate (CuSO4˙5H2O) to determine the relationship between leaf Cu concentration and tobacco sucker control, as measured by per unit reduction of sucker Weights. Leaf Cu was correlated positively with sucker control (r = 0.70) and negatively with sucker weights (r = −0.69). These results indicate that cupric ion can be used as a tracer to measure the spray application efficiency of agricultural chemicals on plants.
Soybean Phosphorus and Potassium Requirement Evaluation by Three M‐DRIS Data Bases
Authors: Hallmark W. B. , Beverly R. B. , Sumner M. E. , DeMooy C. J. , Morris H. F. , Pesek John , Fontenot J. D. 
Published: July 2010

AbstractModified‐diagnosis and recommendation integrated system (MDRIS) soybean (Glycine max L.) norms are now available for select, large, and regional data bases. It is unclear which of these data bases is more accurate in evaluating nutritional needs of soybean. A study was conducted to compare the ability of select, narrow‐based (S); large, broad‐based (L); Midwest (MW); and Southeast (SE) MDRIS data bases to diagnose P and K nutrition in four soybean cultivars grown in a limestone by a P by K soil fertility study in Iowa. Greater accuracy by L, MW, and SE vs. S in evaluating plant P and K status was attributed to spuriously high P and K concentrations in S, which resulted in excessive P and K deficiency diagnoses. Diagnostic accuracy for L and MW did not differ. Greater accuracy of MW vs. SE in detecting P deficiencies was attributed to the larger norm mean for P. The SE performed better than L or MW in determining K nondeficiencies, resulting in superior overall K diagnoses and overall P plus K diagnoses. This was attributed to relatively larger CVs for norms involving K (vs. the average CV for nutrient expressions involving DM) in the SE data base compared to those in the L and MW data bases, which resulted in less incorrect diagnoses by SE where K was nondeficient. Diagnoses by MW were not superior to those for L and SE; therefore, data do not support the suggestion that regional data bases will improve soybean diagnoses for P and K. Data do support the assumption that MDRIS norms from large, broad‐based (L) data sets are more accurate than norms from select, narrow‐based (S) data sets in evaluating plant nutrient requirements.
Prediction of Time to Anthesis of a Selection of Sunflower Genotypes
Authors: Goyne P. J. , Schneiter A. A. , Cleary K. C. 
Published: July 2010

AbstractSynchronization of anthesis of male and female sunflower (Helianthus annuus L.) inbreds to be crossed is important for successful hybrid seed production. The use of weather‐related models, which predict anthesis dates in scheduling planting times could assist in this synchronization. The field plantings of 16 sunflower genotypes in locations from 32°51' S to 64°50' N lat. during 1982 and 1983 were used to develop an anthesis predictive model. This model which related mean daily screen temperature to daily rate of development accounted for genotypes classified into developmental response groups as very quick, quick, medium and slow. The model had satisfactory predictive ability when validated on independent data. The model requires refinement to account for temperature by photoperiod interactions when additional data are available.
Canopy Response of Soybean Affected by Growth Habit and Late Season Competition
Authors: Weil R. R. , Khalil N. , Thomison P. R. 
Published: July 2010

AbstractSoybean [Glycine max (L.) Merr.] isolines that differ only in regard to determinacy have been developed as tools for better understanding the differential responses of determinate and indeterminate types to environmental factors. This study was conducted to investigate the effect of growth habit on soybean yield components at different canopy levels, and on the response of these yield components to environmental conditions during critical reproductive growth stages. Three pairs of near‐isogenic lines (determinate and indeterminate) were grown at three Maryland (USA) locations and subjected to a thinning treatment at the R4 growth stage to release the plants from competition for light, water, and nutrients after pod set was completed. In each plot, six plants were divided into four canopy levels at maturity and hand harvested. For unthinned soybean there was no consistent difference in yield between growth habits. Under low‐moisture conditions at the Beltsville site, the determinates responded more to release from competition than did the indeterminates, indicating that the latter are more buffered against unfavorable growing conditions. Generally seed yield and seed size near the bottom of the canopy was greater in determinates than in indeterminates, but the opposite was true near the top. Thus, the determinate growth habit shifted yield production toward the bottom canopy level. The effect of thinning was nearly uniform at all canopy levels for both stem termination types, increasing the yield of determinates by 38.2 and indeterminates by 13.8%.
Seasonal Growth Rate Patterns for Orchardgrass and Tall Fescue on the Appalachian Plateau
Authors: Denison R. Ford , Perry H. Douglas 
Published: July 2010

AbstractInformation about the seasonal distribution of forage growth rates and variability among years is needed to design improved grazing systems for the Appalachian Plateau. Growth rate and the influence of weather may depend on regrowth stage. Therefore, the objectives of this study were to develop a method to give separate seasonal growth rate curves for plots in the 1st and 3rd wk of regrowth, and to derive such curves for the Appalachian Plateau. The new method, which required 12 harvest schedules (identical except for starting date), was applied to orchardgrass (Dactylis glomerata L.) and tall fescue (Festuca arundinacea Schreb.) growing on a Gilpin silt loam (Typic Hapludult) near Beckley, WV, in 1986 through 1988. Growth rates were highest in spring each year, especially for plots in the 3rd wk of regrowth. Growth rates of plots in the 1st wk of regrowth showed a clear summer slump only in 1987 (during a prolonged drought). For plots in the 3rd wk of regrowth, periods of very low growth rate (apparently due to drought) occurred in both 1987 and 1988, but timing differed by approximately 4 wk between years. Growth rates in fall were generally less than or equal to summer growth rates, except in comparison to drought periods. Grazing strategies based on the expectation of higher growth rates in fall are unlikely to succeed on the Appalachian Plateau.
Leaf Area Development and Dry Matter Production of Cassava
Authors: Manrique Luis A. 
Published: July 2010

AbstractMost published work on cassava (Manihot esculenta Crantz) plant growth and yield responses to environment has been conducted at high latitudes. Little is known of cassava responses to environment when grown at lower latitudes. A field experiment was conducted in Hawaii (21°N lat) during 1986 summer and 1987 winter to study leaf area development and efficiency of dry matter partitioning of cassava when grown under seasonal regimes of temperature and solar radiation. Plants were grown under optimum moisture and nutritional conditions. A series of biomass harvests were collected throughout the growing season to examine effects of temperature and solar radiation on leaf area index (LAI), top and root dry yield, and dry matter partitioning. Maximum LA1 values of about eight and six were attained by 240 d after planting (DAP) in summer and winter, respectively; maximum root growth rates of 17.1 and 13.5 g m−2 d−1 were attained at 240 and 300 DAP in summer and winter. Dry matter partitioning to roots had little seasonal variation and increased with plant age; dry matter partitioning to branches was more sensitive to environment and substantially increased during the summer months. Overall, leaf and root growth proceeded almost similarly in both summer and winter; differences in root yield between seasons were largely determined by differences in dry matter allocation to branches.
Identifying Individual Plants or Plants Parts during Shoot and Root Evaluations
Authors: Douglas C. L. , Toll T. R. , Klepper B. L. , Wilkins D. E. 
Published: July 2010

AbstractIdentity of individual plants or plant parts is often required when making shoot and root measurements. Normally parts from each plant are coded with colored paper clips or put in individually labelled paper or plastic sacks. Both procedures are time consuming and costly. The objective of this project was to develop a method of individual plant or plant part identification that is simple, accurate, economical, and efficient. Materials used are tape and waterproof marker. Individual plants or plant parts are placed on a strip of tape in the order in which they are analyzed. They can then be passed on to another evaluator for further analyses, retaining individual plant identity. This method doubles the number of plants processed/hour and reduces materials cost from approximately$0.13 to less than $0.01/plant.
Leaf Dark‐Adapter for Measuring Chlorophyll Fluorescence in Situ during Daytime
Authors: Selmani A. , Wassom C. E. 
Published: July 2010

AbstractChlorophyll a fluorescence is used as an indicator of stress damage to growing plants. Plants or plant samples first must be transported to a laboratory and dark adapted. If stress (e.g., drought) has not been severe enough to permanently damage the photosynthetic apparatus, plants may recover during dark adaption and stress may not be detectable. In situ readings are more reliable. Dark adaptation takes place after the onset of total darkenss. The objective of this work was to develop a device that would enable the dark adaptation of plant leaves in situ during hours when stress could occur. A thin, light weight sheet of metal was developed to clip onto corn (Zea mays L.) leaves and allow dark adaptation during daylight. A sliding shutter was provided to expose a section of the leaf to light emitted from the fluorometer probe. Using the device, field measurements of daytime chlorophyll a fluorescence were obtained on attached leaves. Measurements were also taken at night on the same plants after dark‐adaptation. In situ day measurements were significantly lower than those taken at night, indicating that stress during daytime influenced the fluorescence response and that plants tended to recover before nighttime readings were taken. Daytime in situ measurements provide an opportunity to detect non‐permanent damage to the photosynthetic apparatus that may show transient drought effects and lowel photosynthetic activity.
Laboratory System for Evaluation of Hay Preservatives
Authors: Baron V.S. , Dick A.C. , Young D.G. 
Published: July 2010

AbstractThe evaluation of additives for the preservation of moist hay through field experiments is made difficult by large and variable experimental units and environmental effects. A laboratory system was developed to rapidly screen hay preservative treatments. Ovendried hay was rehydrated with water and a preservative to the desired moisture concentration. Polyvinyl chloride (PVC) tubes provided the storage vessel. A constant initial density (200 kg m−3) was achieved using a mechanical press. Aeration was by diffusion through the open vessel top. Resistance to heat loss was provided by a fixed, polystyrene bed into which PVC tubes were inserted during a 21‐d incubation at 25 °C. Temperature data handling was facilitated through the use of a mutiplexer and datalogger. Efficacy of a propionate preservative duplicated the performance of previous laboratory systems for temperature and visible mold evaluation. Forage quality parameters followed the same general response to propionate rate within moisture levels as temperature and mold evaluation. Daily temperatures in the laboratory model were comparable to conventional small square bales, but lower than in large round bales.
Soybean Cultivar Response to Planting Rate and Tillage
Authors: Elmore Roger W. 
Published: July 2010

abstractPrevious research has shown that soybean [Glycine max (L.) Merr.] cultivar yield responses to tillage systems can vary in specific environments due to drought stress, diseases, or herbicides. In one of 3 yr in a previous study ‘Mead’ yielded 15% more in no‐tillage than in tilled systems while ‘Williams 82’ yielded 8% less in notillage than in tilled systems. This was thought to be due to either a slight difference in plant populations between the two cultivars or genetic variability that could be used to develop tillage‐specific cultivars. The study reported here was conducted to determine if planting rate of these two cultivars affected their responses to tillage. A 2‐yr field study was conducted with two cultivars (Mead and Williams 82) at four planting rates (11.1, 34.6, 58.1, and 81.5 seeds m−2) and two tillage systems (no‐tillage and triple disk). In 1986, the study was conducted on a Crete silt loam soil (fine, montmorillonitic, mesic Pachic Argiustoll), which is moderately well drained with slow permeability. In 1987, the study was conducted on a Hastings silt loam soil (fine, montmorillonitic, mesic Udic Argiustoll), which is well drained with moderately slow permeability. When averaged over planting rate, the cultivars responded similarly to tillage systems. Planting rate did not affect the responses of the cultivars to tillage system. Mead and Williams 82 appear to respond similarly to tillage systems in most environments regardless of planting rate.
Limitations to Bromide Determinations in Alfalfa Using the Bromide‐Selective Electrode
Authors: Meyers L. L. , Russelle M. P. 
Published: July 2010

AbstractBromide is a potential tracer of nutrient uptake by plant roots in soil‐plant systems, yet traditional methods of Br analysis have been time consuming, expensive, or difficult to complete. The bromide‐selective electrode (BrSE) has been used with some success as a simple means to accurately determine Br in soils and plant materials. We tested 0.1 M NaNO3 and 0.025 M Al2(SO4)3 as extractants of Br in alfalfa (Medicago sativa L.) for determination with a BrSE and investigated BrSE interferences from Cl and soluble proteins. Sodium nitrate was eliminated as an extractant due to unstable potentials and gross overestimation of added Br. Extraction with Al2(SO4)3 resulted in stable potentials and accurate recovery of added Br, but x‐ray fluorescence analysis showed that the BrSE overestimated tissue Br by 1.3 to 14 times. Overestimation of Br was strongly correlated with the ratio of Cl:Br in the extracts and the BrSE was affected by relatively low [Cl] at [Br] lower than 4 mg L−1. The BrSE is neither an accurate nor a simple means of Br analysis in alfalfa.
Relationship of Diagnostic Nutrient Expressions to Soybean Phosphorus and Potassium Diagnoses
Authors: Hallmark W. B. , Beverly R. B. , deMooy C. J. , Pesek John 
Published: July 2010

AbstractResearch is lacking as to whether forms of nutrient expression (e.g., N/P vs. P/N, etc.) and placement of nutrient variables (N, P, K, etc.) and/or dry matter (DM) exclusively in the numerator vs. the denominator of function values affects nutrient diagnoses by the modified‐diagnosis and recommendation integrated system (M‐DRIS) using the Jones (J) and Traditional (T) methods. Consequently, a soybean [Glycine max (L.) Merr.] cultivar‐by‐P‐by‐K‐by‐limestone soil fertility field study conducted on a Cresco loam (fine loamy mixed, mesic Typic Argiudoll) was used to determine whether these variations affect P and K diagnoses. Forms of expression affected T diagnoses, and placement of DM in the numerator vs. the denominator of functions had an effect on both T and J diagnoses. Effects of nutrient expression and DM placement on T diagnoses were caused by systematic errors in the M‐DRIS norms. These biases were largely alleviated when nutrient indices were calculated so that the variable under consideration always appeared in the numerator or the denominator of the function. Diagnoses by J were more accurate, however, when variables were placed in the denominator. Our results show that the effects of nutrient expression, calculating functions by T and J, and DM placement on M‐DRIS diagnoses can be largely alleviated when index values are calculated so that the variable under consideration is always in the numerator or denominator of the function.