bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correction of Mn Deficiency of Soybeans1
Authors: Alley M. M. , Rich C. I. , Hawkins G. W. , Martens D. C. 
Published: July 2010

AbstractThe objective of this study was to compare rates of Mn application and methods of Mn application to correct Mn deficiency of soybeans (Glycine max L.) in planting systems where no starter fertilizer is utilized. Field experiments were conducted at three locations in the Coastal Plain region to evaluate broadcast and foliar applications as well as band placement of granular Mn fertilizer in the row with seed. The latter application was accomplished by utilizing a conventional granular insecticid applicator. Soils studied in this investigation included two aquic hapludults and one typic quartzipsamment.Applications of 5.6, 11.2, and 16.8 kg Mn/ha bandplaced in the row with seed produced yield increases of soybeans on both limed and unlimed areas at one location. Soybean yield increases were obtained at this location from broadcast applications of 11.2, 22.4, and 44.8 kg Mn/ha on the unlimed soil, and from the 22.4 and 44.8 kg Mn/ha on the limed soil. A foliar treatment of 2.2 kg Mn/ha also produced grain yield increases. Only the 11.2 and 16.8 kg Mn/ha band‐placed with seed, and the 11.2 kg Mn/ha broadcast treatments on the limed soil gave soybean yield increases at a second location. Drought conditions prevailed at the third site and no soybeans emerged on the 11.2 and 16.8 kg Mn/ha bandplaced with seed treatments.In planting systems where conventional band placement of fertilizer is not practical, band placement of Mn in the row with seed can increase yields on soils supplying insufficient Mn for plant growth. Plant populations can be reduced by band placement of Mn in the row with seed under adverse moisture conditions. Broadcasting high rates of Mn or repeated foliar applications of Mn will also correct Mn deficiency of soybeans.
Water and Nutrient Response of Semi‐dwarf Wheat under Improved Management in Pakistan: Agronomic and Economic Implications1
Authors: Eckert J. B. , Chaudhry N. M. , Qureshi S. A. 
Published: July 2010

Abstract‘Chenab‐70’ cultivar of semi‐dwarf wheat (Triticum aestivum L.) was grown under improved management conditions with several levels of N, P and irrigations. An incomplete factorial design included N levels of 0, 56, 112, 168, and 224 kg/ha and 1, 2, 3, 4, 5, and 6 irrigations. Each irrigation consisted of 7.6 cm applied water. Irrigations were optimally sequenced with crop growth stages as indicated by prior research in India and Pakistan. The resulting quadratic production functions indicate that yield levels now obtained by the best farmers can be obtained with one‐third to one‐half of the water currently being applied if irrigations are timed and controlled appropriately. Fertilizer response also exceeded that obtained by progressive farmers. Economically optimum application rates for water and N were rather restrictive with little opportunity for substitution. Finally, soil moisture measurements coupled with concurrent physiological and morphological observations are used to rationalize the persistence of indigenous cultural practices and to suggest new cultural practices to further enhance irrigation efficiency.
Role of Anthracnose in Stand Thinning of Alfalfa in Delaware1
Authors: Jones E. R. , Carroll R. B. , Swain R. H. , Bell K. W. 
Published: July 2010

AbstractAnthracnose, caused by Colletotrichum trifolii Bains, is widespread on alfalfa (Medicago sativa L.) in Delaware and thinning of alfalfa stands is believed to be at least partially due to anthracnose. The purpose of this field study was to determine the effect of C. trifolii on winter survival of alfalfa. Alfalfa plants growing on a Typic Haplueults soil, with and without symptoms of anthracnose, were tagged prior to winter dormancy to determine the effects of C. trifolii on winter survival. Other factors affecting winter survival of alfalfa were evaluated by removing another group of plants with and without anthracnose symptoms from the experimental site before winter dormancy. The following parameters were evaluated: root and crown rot, insect feeding on root and crown tissues, presence of new crown buds, root and crown tissue weights, and total nonstructural carbohydrate levels. Soil surrounding the roots of removed plants was analyzed for soil acidity, P, K, Ca, Mg, and B. Colletotrichum trifolii‐infected plants had 22 to 85% lower winter survival values when evaluated the following spring. Colletotrichum trifolii‐infected plants evaluated prior to winter dormancy had 7% smaller root systems and 29% fewer plants with new crown buds, but did not have significantly different levels of crown and root rot or root insect damage. Soil tests, indicated no relationship between soil parameters measured and anthracnose. It is concluded that anthracnose was the principal factor responsible for stand thinning of alfalfa during the winter dormant period.
Short‐statured Rice Response to Seeding and N Rates1
Authors: Wells B. R. , Faw Wade F. 
Published: July 2010

AbstractResearch on response of direct seeded rice (Oryza sativa L.) to interactions of seeding rate and N rate is very limited, although considerable work has been done in the tropical countries with transplanted rice. Understanding responses by U.S. rice cultivars to these factors is important not only for optimizing management, but also because it provides information concerning the need for further improvement of plant type. Therefore, our objective in this study was to determine what factors might limit performance of ‘Starbonnet’ rice when subjected to a range of seeding and N rates. This study was conducted in field plots for 2 years on a Crowley silt loam soil (Typic Albaqualf) at the Univ. of Arkansas Rice Branch Experiment Station, Stuttgart, Ark. A split plot design was used. Time of N application (preplant or topdress) was the main plot and all possible combinations of seeding rates of 67, 135, and 303 kg/ha and N rates of 67, 135, and 202 kg/ha were the subplots. All treatments were replicated four times. The following measurements were taken: grain yield; stand counts prior to tillering and at maturity; blanks per panicle; florets per panicle; dry weight at heading and maturity; percent N in the flag leaf at heading; leaf area index (LAI) at headingExcessive vegetative growth before anthesis limited grain yield from dense plant populations. This was evidenced by high LAI at heading, reduced dry matter accumulation after heading, and adequate N levels in the flag leaf under conditions of dense population. Further indication of the effect of excessive vegetation prior to anthesis was shown by the fact that number of florets per panicle had more influence on grain yield than did blanks per panicle.Increasing the N rate from 135 to 202 kg/ha increased grain yield only for the 67 kg/ha seeding rate in 1972. Time of N application (preplant or topdress) did not influence grain yield.Under the direct seeding conditions of this study initial plant population, rather than tillering, accounted for the number of panicles per unit area. As seeding rate and plant population increased, number of florets and blanks per panicle decreased. Increasing the N rate increased both florets and blanks per panicle. Both increased seeding rate and N rate resulted in increased LAI.Under the conditions of this test the major factors that limited yield under dense population appeared to be light and CO2, since extra N fertilizer was ineffective.
Dry Matter Production and Translocation in Maize Subjected to Drought during Grain Fill1
Authors: Jurgens S. K. , Johnson R. R. , Boyer J. S. 
Published: July 2010

AbstractBecause dry conditions most frequently occur during the second half of the growing season, the yield loss to be expected and the physiological mechanisms that cause the loss need to be understood in grain crops. In order to study this problem, the objective of this research was to withhold water from field‐grown maize (Zea mays L.) during the grain filling stage to determine the relative effects of drought on photosynthesis and translocation. Located in bordered field plots, plants were grown in large pots arranged in 75‐cm row widths at a density of 40,770 plants/ha. Drought imposed 10 days after pollination caused leaf water potentials to range between −15 and −19 bars during the day for the rest of the growing season. In control plants, daytime leaf water potential remained between −3 and −16 bars. Soon after drought was imposed, leaf area began to decline and grain yield was ultimately reduced to 42% of the control. The drought increased grain protein concentration but decreased oil concentration.Analysis of dry matter accumulation showed that, as grain development progressed, the rate of grain fill began to exceed the rate of dry matter accumulation, indicating a net redistribution of stored assimilates. In the desiccated plants, the redistribution continued after the cessation of net plant dry matter production and occurred earlier and to a larger extent than in controls. A 14C translocation study confirmed that grain fill drew on stored photosynthate to a greater extent in desiccated plants than in controls. Because of this redistribution of photosynthate, grain yield was related to the total dry matter accumulated by the plants during the growing season. It should be emphasized that the experiment was designed to assure complete floral development and fertilization and, therefore, the sink size for photosynthate was the same in the desiccated and control plants.To measure translocation during the drought, the second leaf above the ear was exposed to 14C 7 and 21 days after water was withheld. The amount of 14C translocated was inhibited by the dry conditions. On the first exposure date, desiccated plants retained a higher percentage of the 14C in the exposed leaf and translocated a lower percentage of the 14C to the grain than on the second exposure date. On the second exposure date, the proportion of 14C in the grain was not significantly different from that in the control plants. This continued translocation, despite a lack of plant dry matter accumulation, indicates that photosynthesis was more inhibited than translocation during the dry conditions. The differences in 14C translocation at different times suggest that interpretations of long term drought effects on translocation should be based on extended studies of dry matter or 14C movement rather than short term movement of 14C alone.
Foliar Application of P. II. Yield Responses of Corn and Soybeans Sprayed with Various Condensed Phosphates and P‐N Compounds in Greenhouse and Field Experiments1
Authors: Barel D. , Black C. A. 
Published: July 2010

AbstractGreenhouse and field experiments were conducted with corn (Zea mays L.) and soybeans (Glycine max L. Merr.) to evaluate the growth response of foliar sprays with several condensed phosphates and P‐N compounds. The maximum concentration of P tolerated in solutions of tri‐ and tetrapolyphosphates applied as sprays in the greenhouse was 1.3% with corn and 1.1% with soybeans. The maximum concentration of P tolerated as orthophosphate was 0.5% with corn and 0.4% with soybeans. With soybeans, the yields of plants sprayed with various condensed P compounds significantly exceeded the yields of the unsprayed control, which would not be classed as P‐deficient on the basis of the P content of the leaves. Spraying the plants, however, increased the P concentration in the leaves. Phosphoryl triamide produced the highest yields of above‐ground dry matter of corn plants in an experiment in which several P‐N compounds and condensed phosphates were brushed on the leaves. Several different condensed phosphates were sprayed on corn and soybeans in a field experiment on a fine loamy, mixed, mesic typic haplaquoll (Webster silt loam). An increase in yield of corn that was statistically significant at the 5% level was obtained from spraying. The yields with tri‐ and tetrapolyphosphate were, respectively, 760 and 754 kg/ha above the control yield of 10,234 kg/ha. With soybeans, the increase in yield due to treatment was significant at the 18% level, and the increase was equivalent to 256 kg/ha above the control yield of 3747 kg/ha.
Yield and N Percentage of Spring Wheat as Affected by Phosphate Fertilizer Moisture Use, and Available Soil P and N1
Authors: Nutall W. F. , Zandstra H. G. , Bowren K. E. 
Published: July 2010

AbstractYield response of wheat (Triticum aestivum L.) to P fertilizer is quite variable on summerfallowed fields in western Canada. Because yield response to P fertilizer was only partially explained by NaHCO3‐soluble P (available soil P), experiments were conducted in northeastern Saskatchewan to evaluate N and moisture effects on yield response and protein percentage of wheat.Over a 4‐year period, 18 N and P fertilizer trials with spring wheat were seeded on six soil types of the Black (Udic Haploboroll), Dark Gray (Mollic Cryoboralf), and Gray Wooded (Typic Cryoboralf) soil areas in northeastern Saskatchewan. Before seeding, soil samples were taken for N and P soil analyses and moisture determination. Maximum and minimum air temperatures and rainfall were recorded daily at each site in order to make estimates of soil moisture by a budget system (rainfall minus evapotranspiration) throughout the growing season.Grain yields ranged from 1297 kg/ha (control) on a soil having a NaHCO3,‐soluble concentration of 8.4 µg P/g to 4,973 kg/ha where 11 kg N and 22 kg P/ha were applied on a soil testing 17.9 µg P/g. Wheat yield responses were negatively correlated with sodium NaHCO3‐soluble P, exchangeable ammonium‐N and positively correlated with nitrate‐N in soil at planting. Negative correlations occurred between wheat yield response and soil moisture deficit (rainfall minus evapotranspiration) at both heading to soft dough and from soft dough to ripe growth periods; wheat yield response was positively correlated with moisture deficit from jointing to heading (mean R2 = 77.6%). Yield response at the highest rate of 29 kg P/ha was not significantly affected by moisture deficit. Yields of the control had a significant quadratic relationship to NaHCO3‐soluble P (R2 = 64.3%).Nitrogen percentage of the controls was increased by high nitrate‐N in soils. With but one exception, high moisture use and low moisture deficit at later growth stages were associated with lower N percentage of grain (mean R2 = 91.4%).Most of the variability of wheat yield response to P fertilizer was accounted for by soil N, P, and moisture. Management practices that will increase the amount of N in the soil and reduce the amount of water available in the late stages of crop development will produce grain with the highest protein percentage on summerfallow fields in northeastern Saskatchewan.
Physiological and Morphological Characteristics of Large and Small Leaflet Alfalfa Genotypes1
Authors: Leavitt J. R. C. , Dobrenz A. K. , Stone Joe E. 
Published: July 2010

AbstractA rapid test for identifying high‐yielding genotypes of all crop plants, including alfalfa (Medicago sativa L.), is needed. Because previous work indicated that alfalfa yield is closely associated with leaflet size, 15 alfalfa genotypes with large primary leaflets and 13 alfalfa genotypes with small primary leaflets were identified by visual selection in the field and compared for yield, leaflet size, specific leaf weight (SLW), and rate of carbon exchange in the spring of 1974. The large leaflet alfalfa genotypes had significantly higher yield, larger leaflets, and lower SLW than the small leaflet genotypes when the data were combined over the entire growing season. The large leaflet genotypes had significantly higher rates of total photosynthesis per plant, significantly lower rates of apparent photosynthesis per unit leaf area than the small leaflet genotypes, and equal rates of apparent photosynthesis per gram of leaves to those of the small leaflet genotypes.Correlation coefficients were calculated between the various morphological and physiological parameters measured on all genotypes. The best selection criteria for yield was total leaf area per plant (r=0.92, significant at 1% level). Dry matter production was positively and significantly associated with total CO2 uptake per plant (r=0.63, 1% level) and leaflet area of primary leaflets (r= 0.47, 1% level). Although apparent photosynthesis showed a significant but negative (r=−0.26, 570 level) association with yield, its predictive value was low. Carbon exchange, apparent photosynthesis, dark respiration, post‐illumination‐burst, and photorespiration were significantly and positively associated with each other. Further research is needed to determine if vegetatively propagated swards of large leaflet alfalfa would outyield swards of small leafet afalfa.
Pima and Upland Cotton Response to Irrigation Management1
Authors: Kittock D. L. 
Published: July 2010

AbstractAmerican Pima cotton (Gossypium barbadense L.) traditionally is stressed more for moisture before irrigating than is Upland cotton (G. hirsutum L.). With improved cultivars of each species, many growers now irrigate both in a similar manner. The purpose of this research was to determine if current cultivars of the two species respond differently to irrigation. Upland and Pima cultivars were compared for 4 years under five irrigation regimes at Phoenix, Ariz. Water was metered into closed basins. Treatments consisted of watering every 7, 14, and 21 days for 4 years. Additional treatments for 2 years were watered every 28 days and watered every 7 days at 50% more water than the original 7‐day treatment. Highest yield of Pima cotton was from a treatment of one irrigation regime drier than Upland cotton in 3 of 4 years and the same regime for 1 year. Pima cotton lint yield was reduced more by excess water and less by water stress than was the yield of Upland cotton. Higher lint yields were obtained under less frequent irrigation (greater water stress) in years of low productivity. These data suggest that yield of Upland cotton may be increased by more frequent irrigation than is the current practice.
Estimating Nodule Activity of Sainfoin, Alfalfa, and Cicer Milkvetch Seedlings1
Authors: Major D. J. , Hanna M. R. , Smoliak S. , Grant R. 
Published: July 2010

AbstractLegume cultivars with improved symbiotic dinitrogen‐fixing capabilities greatly benefit agriculture. Limited research on several forage legume species has suggested that breeding for improved dinitrogen fixation should be possible, but effective screening techniques are needed if significant breeding progress is to be made. This paper describes a study conducted on three forage legumes to determine the relationship of several plant characteristics to dinitrogen fixation, with a view to developing a nondestructive method of identifying plants with superior dinitrogen‐fixing ability.Growth of 500 seedlings of sainfoin (Onobrychis viciaefolia Scop.), 425 of alfalfa (Medicago sativa L.), and 417 of cicer milkvetch (Astragalus cicer L.) was measured in a N‐free rooting medium. At harvest, seedlings were clipped above the cotyledonary node, nodules were removed and dry weights of shoot, root, and nodules were determined. The amount of acetylene reduced by nodules and the nitrogen content of shoots were determined on one‐fifth of the plants before harvest. Large variations were observed for all of the variables measured. For all three species, variation in nodule dry weight accounted for 60 to 71% of variation in shoot dry weight. Variation in nodule activity, as measured by the acetylene reduction assay, accounted for 18 to 45% of variation in shoot dry weight. These results suggested that shoot dry weight was a good estimator for nodule dry weight and nodule activity in a N‐free rooting medium.The amount of acetylene reduced by alfalfa nodules was not as closely related to shoot dry weight as it was for sainfoin or cicer milkvetch. A poor relationship between shoot percent N and shoot growth in sainfoin and alfalfa suggested that all available N in the shoot was used for top growth by these species, whereas in ucer milkvetch, a portion of the N in the shoot was not used for growth.
Influence of N and P on the Yield and Chemical Composition of Quackgrass Growing on an Organic Soil1
Authors: Schoper R. P. , Malzer G. L. , Simkins C. A. 
Published: July 2010

AbstractInfestation of pure grass swards by quackgrass (Agropyron repens L.) has been a problem in grass production on organic soils in northern Minnesota. To determine if these problem areas could be utilized and managed effectively for forage production of quackgrass, trials were established in 1974 to determine the influence of N and P fertilization. In 1975, N and P fertilizer treatments were reapplied to the same plots.In this 2 year study, the effects of 9 N and 5 P treatments were studied on an existing stand of quackgrass on an organic soil in northern Minnesota. Nitrogen at 168 kg/ha significantly increased dry‐matter yields by 62% in the first year, and 66% in the second, with a maximum yield of 6.96 metric tons/ha. Splitting of N applications influenced seasonal forage production, but had no effect on total yield. The percent crude protein ranged from 15.8 to 27.9, and was significantly increased by the application of N. Phosphorus at 50 kg/ha increased dry matter yields by 37% in the first year, and 52% in the second, with a maximum yield of 7.30 metric tons/ha. The application of P fertilizer significantly increased the P concentration of the plant tissue with optimum yields being obtained with tissue P concentrations ranging from 0.24 to 0.41%.
Phosphite Injury to Corn1
Authors: Lucas R. E. , Warncke D. D. , Thorpe Virginia A. 
Published: July 2010

AbstractA liquid fertilizer containing phosphite was toxic to over 1,000 ha of corn (Zea mays L.) in southern Michigan. The fertilizer contained 9% N, 8% P, and 7.5% K and was applied over the seed at planting time. Toxicity was also obtained when the foliage was sprayed with the same fertilizer. Laboratory tests using paper chromatography and greenhouse trials identified the P source as a phosphite (HPO3)−2. Plants showed white, variegated streaking of the leaves in mild cases and spindly, rolled, yellowish‐white leaves in severe toxicity.