bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amino Acid Composition of Tall Fescue Seed Produced from Fungal Endophyte (Acremonium coenophialum)‐Free and Infected Plants1
Authors: Belesky D. P. , Evans J. J. , Wilkinson S. R. 
Published: July 2010

AbstractThe presence of a fungal endophyte (Acremonium coenophialumMorgan‐Jones and Gams) in tall fescue (Festuca arundinaceaShreb.) has been associated with the production of nitrogenous secondary metabolites such as the pyrrolizidine alkaloids. The increased production of secondary metabolites may alter the N balance of the plant affecting the types and amounts of nitrogenous products available for export to developing seed. An investigation was conducted to determine the impact of fungal endophyte status on the amino acid composition of tall fescue seed. New (viable endophyte) and old (stored for at least 2 yr, nonviable endophyte) seed of ‘Kenhy’, ‘KY‐31’, an experimental line “EXP” and ‘Fawn’ were sown in a randomized block design. New seed of Fawn failed to germinate. Seed sown, vegetative tissue, and seed produced were assayed for fungal endophyte status. Endophyte levels in vegetative tissue and seed produced from plants established from old seed were low in fungal endophyte (<20%). Qualitative evaluation of seed amino composition (grams amino acid per 100 grams amino acid recovered) did not reveal any significant alterations in amino acid composition, which could be attributable to fungal endophyte status of the parent plant.
The Effect of Root Temperature and Nitrate/Ammonium Ratio on Strawberry Plants. II. Nitrogen Uptake, Mineral Ions, and Carboxylate Concentrations1
Authors: Ganmore‐Neumann Ruth , Kafkafi U. 
Published: July 2010

AbstractStrawberry plants (Fragaria ananasa Duch.) have shallow roots and are grown in the field during both hot and cold seasons. The possibility of irrigating and fertilizing the plants daily, through the trickle system, led to the question of what is the best nitrogen form and NO−3/NH+4ratios to be supplied to this crop during the growing season. The effect of four root temperatures (10, 17, 25 and 32 °C) and five NO−3/NH+4mole ratios (0⁄7, 2⁄5, 3.5⁄3.5, 5⁄2, 7⁄0) at constant total N in the solution was studied. To keep constant pH, total nutrient solution and root temperature, continuous flow techniques were used. The solution was flushed through 1‐L pots at the rate of 1 L h−1. When both N forms were present, the rate of total N uptake was higher than when NH+4or NO−3alone was present. The maximum uptake rate was found at 25 °C root temperature. Best conditions for growth were found at 25 °C root temperature when both N forms were present in equal concentration. A preference for NO−3uptake was found during flowering and the fruiting period. Ammonium was preferred during the vegetative growth period. Increasing root temperature decreased total cation concentration and especially that of K+, Na+, and Mg2+, and increased Ca2+in the roots of NO−3‐fed plants. The Na+was accumulated in the crown and did not move to the leaves and fruits. Increasing root temperature reduced inorganic anion concentration in the roots while increasing it in leaves of NH+4fed plants. In the fruits, the ratio of mole of charges of Ca2+to that of H2PO−4was about 1:1 for both N forms.
Transmitted and Absorbed Photosynthetically Active Radiation in Grain Sorghum1
Authors: Rosenthal W. D. , Arkin G. F. , Howell T. A. 
Published: July 2010

AbstractRelationships defining transmitted (TPAR) and absorbed (APAR) photosynthetically active radiation (PAR) in sorghum [Sorghum bicolor(L.) Moench] canopies do not account for senesced leaves, stalks, and panicles after anthesis. Absorbed PAR by senesced leaves does not directly contribute to photosynthesis, whereas PAR absorbed by panicles does. In addition, senesced leaves, stalks, and panicles reduce transmitted solar radiation reaching the soil and thereby affect soil evaporation. The objective of the study was to examine the combined effect of senesced leaves, stalks, and panicles on TPAR and APAR in a developing sorghum canopy before and after maximum green leaf area index (GLAI) was attained. The study was conducted on a Panoche clay loam (fine‐loamy, mixed, thermic Typic Torriorthent) at the West Side Field Station (CA) near Five Points, CA during 1982 and on a Houston black clay (fine‐montmorillonitic, thermic Udic Pellustert) at the Blackland Research Center (TX) in Temple, TX, during 1983. The experimental designs were three replications of four and five altered canopy treatments (panicles and layers of green and senesced leaves removed) at TX and CA, respectively. Transmitted and absorbed PAR were calculated from PAR measurements above and below the canopy, before and after maximum green leaf area was attained. Transmitted and absorbed PAR differed significantly (95% level) before and after maximum leaf area index was attained. Panicles intercepted 8% of the incoming PAR; stalks 14%; and senesced leaves, 23%. Relationships derived between TPAR and GLAI compared favorably with other published data. Absorption of PAR by panicles, stalks, and senesced leaves should be considered in photosynthesis, evapotranspiration, and crop growth estimates.
Growth, Nitrogen Uptake, and Partitioning in Nitrogen‐Fertilized Nodulating and Nonnodulating Peanut1
Authors: Selamat A. , Gardner F. P. 
Published: July 2010

AbstractPeanut (Arachis hypogaeaL.) is known to be effective in symbiotic N2fixation, but N deficiencies may occur during rapid vegetative and/or reproductive growth. The effects of N fertilization on growth, N uptake, and N partitioning in nodulating and nonnodulating peanut genotypes were studied during 1982 in the field and a greenhouse experiment at the University of Florida, Gainesville. Three lines, 'Florunner' (FL), 'Early Bunch' (EB), and a nonnodulating line ('M4‐2') were grown in the field on a Lakeland sandy soil (hyperthermic coated Thermic Quartzipsamment) at four N rates (0, 6, 12, and 24 g m−2N) and in pots in the greenhouse at N rates at a factor of 0.05, 0.50, 0.95, and 1.40 N‐strength of Hoagland no. 2 solution, modified to adjust the other nutrients at 0.50 strength. In the field experiment, only the biomass crop growth rate (CGR) and leaf area index (LAI) of all genotypes were significantly increased by N rates. A leaf area index of 3.0 was achieved at 60 days after planting (DAP) when 6 g m−2N or more was applied on the nodulating genotypes. For the nonnodulating genotype (M4‐2), 120 days at 6 g m−2N or 85 days at 24 g m−2N were required to achieve LAI of 3.0. The vegetative and reproductive responses of M4‐2 to N increments were highly positive and essentially linear. Pod and seed yields of nodulated genotypes in field‐grown plants were not significantly influenced by N fertilization. Pod yields were increased in pot‐grown plants in the greenhouse, but nodule number and weight were reduced. A genotype X N rates interaction for plant component yield, leaf N concentration, and N content was observed due primarily to the differential response to N between the nodulating and nonodulating lines. Partitioning of photoassimilate to pods was generally reduced by N fertilization, probably due to vegetative growth stimulation. Florunner cultivar biologically fixed more N2than EB, the amount in FL exceeding the seed requirement (12.2 m−2) if fertilizer N rate was low. These studies suggest that the practice of N fertilization of well‐nodulated peanut does not increase pod or seed yield and is economically counter‐productive.
Partitioning of Assimilate Between Vegetative and Reproductive Growth in Soybean1
Authors: Egli D. B. , Guffy R. D. , Leggett J. E. 
Published: July 2010

AbstractChanges in the proportion of the total biomass harvested have made an important contribution to the increase in yield in several grain crops. Field experiments were conducted for several years on Typic Argiudoll and Typic Paleudalf soils to investigate the effect of cultivars, growth habit, and environmental conditions on the partitioning of assimilate between vegetative and reproductive plant parts in soybean [Glycine max(L.) Merr.] during flowering and fruit set. The experiments included the following variables; cultivars from maturity group II to V, including both indeterminate and determinate growth habits, optimum and delayed plantings, and moisture stress. Data were collected from growth stage R1 to R6 on vegetative growth characteristics (nodes on main stem, total nodes, and plant height), pod development, and weight of vegetative and reproductive plant parts. Partitioning coefficients were calculated by dividing fruit weight by the total aboveground biomass. The nodes on the main stem and on the branches reached a maximum at R5 in all cases. Determinate cultivars produced fewer nodes on the main stem between R1 and R5; however, they produced more branch nodes and the total node production was greater than the indeterminate cultivars. The number of pods containing developing seed increased until approximately R6, suggesting that the production of new vegetative sinks (node production) in soybean stopped before the total fruit load was established. The partitioning coefficients increased rapidly from < 5% at growth stage R3 to ≥ 30% at R6. The partitioning coefficient at any growth stage varied only slightly across the variables included in the experiments. This suggests that variation in fruit and seed number may be more closely related to variations in crop growth rate than to variations in the allocation of assimilate between vegetative and reproductive plant parts.
Photosynthetic Response of Soybean Canopies to Full‐Season Carbon Dioxide Enrichment1
Authors: Acock B. , Reddy V. R. , Hodges H. F. , Baker D. N. , McKinion J. M. 
Published: July 2010

AbstractGlobal atmospheric CO2concentration ([CO2]) is increasing as a result of the burning of fossil fuels. At present there is little information about how agronomic crops will respond to future high [CO2]. To investigate the basic process that will be most affected, soybean [Glycine max(L.) Merr.] canopies were continuously exposed to various [CO2] and photosynthetic rates were measured throughout the growing season. Soybean was grown to physiological maturity in sunlit controlled‐environment chambers in CO2concentrations of 330, 450, 600, and 800 µL L−1. Carbon dioxide fluxes were measured on the canopies at 15‐min intervals every day and used to calculate photosynthetic and respiration rates. Gross photosynthetic rate increased with each increment in [CO2] regardless of stage of development, but there was considerable day‐to‐day and seasonal variation. Seasonal changes in photosynthetic rate were associated with developmental changes in the crop. Photosynthetic rates were low during early vegetative development, even after the canopy had closed, but increased threefold just before flowering to reach a peak during flowering at stage R2. They then decreased by 30% or more until just before the start of pod expansion (R3) when a 45% increase occurred. Thereafter, photosynthetic rates decreased slowly and continuously to final harvest. The daily curves of photosynthetic rate vs. photosynthetic photon flux density were further analyzed to determine canopy light utilization efficiency (α) and canopy conductance to CO2transfer (τ). Plants grown in 800 µL L−1[CO2] had a value of τthat averaged about 40% higher than that for plants grown in 330 µL L−1and a value of τthat averaged about 24% lower for the season. Differences in α between these treatments were significant throughout the season, while initial differences in τbetween treatments became less obvious after late vegetative growth stage V11.
Soil Fertility Responses of Virginia‐type Peanut Cultivars1
Authors: Coffelt T. A. , Hallock D. L. 
Published: July 2010

AbstractDifferential nutrient contents of peanut (Arachis hypogaeaL.) cultivars in previous studies have demonstrated a need to monitor newly developed cultivars for nutritional peculiarities. Nutrient uptake of large‐seeded, virginia‐type peanut cultivars ‘Florigiant’, ‘Early Bunch’, ‘Virginia 81 Bunch’, ‘NC 7’, and ‘NC 6’ was determined under two fertility treatments (low and high) and two Ca treatments at the high fertility treatment (with and without). The low fertility treatment was 448 kg ha−1of 3–9–18 fertilizer applied to corn (Zea maysL.) prior to peanuts. The high without Ca fertility treatment was 1344 kg ha−1of 3–9–18 fertilizer applied to corn prior to peanuts. In addition, peanuts received 34 kg ha−1Mn, 3.4 kg ha−1Zn and Cu, and 0.6 kg ha−1B prior to planting. The high plus Ca fertility treatment was the same as the high without Ca treatment except 1344 kg ha−1of landplaster was applied to the peanuts at early pegging. The experiment was conducted at Suffolk, VA for 3 yr (1980–1982) on a Wagram loamy fine sand (loamy, siliceous, thermic, Arenic Paleudult). Petioles and leaflets were analyzed for Ca, P, K, Cu, Mg, Mn, Zn, and Fe at early pegging and harvest, and pod yield was determined all 3 yr. Seed germination, seed nutrient content, and market grade were determined in 1981 and 1982. Significant differences occurred among cultivars and fertility treatments for nutrient content of petioles, leaflets, and seeds; yield; market grade; and germination. Leaf tissue contents of Mn, K, and Mg and seed contents of Ca, K, Mg, Fe, Cu, and Zn varied more with fertility treatment than the other nutrients. Leaves of Virginia 81 Bunch (VA 81B) and seed of NC 6 were consistently low in most nutrients, while seed of VA 81B and leaves of NC 6 were not. These results indicate that cultivars differ in nutrient requirement, nutrient uptake, or the redistribution of nutrients. Yield, grade factors, and germination were higher and pod rot lower for the high fertility + Ca treatment than for the other fertility treatments. Simple correlations also showed that the relationship of Ca and K was important in seed germination and the incidence of pod rot.
Aluminum, Citric Acid, Nitrilotriacetic Acid, and Soil Moisture Effects on Aluminum and Iron Concentrations in Ryegrass1
Authors: Muchovej R. M. C. , Allen V. G. , Martens D. C. , Zelazny L. W. , Notter D. R. 
Published: July 2010

AbstractSeasonal variations in Al and Fe content of pasture forage samples have been generally attributed to soil contamination although mechanisms for plant Al uptake have been suggested. Aluminum and Fe concentrations in annual ryegrass (Lolium multiflorumLam.) grown at two soil moisture levels, flooded and 80% field capacity (FC), with Al added as chelates of citric or nitrilotriacetic acid (NTA) at 0, 33.5 67,100.5, and 134 mg kg−1or chelates added alone, were investigated in a greenhouse experiment. Effects of treatments on soil pH and exchangeable Al were investigated with and without plants present. Plants grown for 10 weeks were harvested at two heights: 6 cm [above 6 cm = upper growth] and ground level (0–6 cm = lower growth). Flooding, chelates, and A1‐chelates increased Al concentrations in plants harvested at both heights. In lower growth, Fe increased only in response to flooding and A1‐NTA. Highest tissue Al concentration occurred with addition of 134 mg Al kg−1as A1‐NTA with values of 850 and 140 mg kg−1in lower and upper growth, flooded, and 480 and 110 mg kg−1in lower and upper growth at 80% FC, respectively. Respective controls contained 410, 67, 133, and 37 mg kg−1Al. Flooding increased soil pH and exchangeable Al. Chelates and Al‐chelates increased soil exchangeable Al. Results show potential for increased plant Al concentrations, particularly under flooded conditions, and suggest chelation with organic acids as an Al uptake mechanism which could affect animal nutrition. For critical determinations, AI should not be used as an indicator of soil contamination in plant samples
Influence of Protective Covers on Reducing Winter Desiccation of Turf1
Authors: Roberts J. M. 
Published: July 2010

AbstractLoss of turf to desiccation in the later winter and early spring continues to be a major problem especially in northern climates. Reported is a 2‐yr field study to determine the value of synthetic and natural coverings for protection of putting green turf. Studies were made in 2nd and 3rd stand yr on creeping bentgrass (Agrostis palustrisHuds. ‘Emerald’) growing in a Charlton fine sandy loam (coarse‐loamy, mixed, mesic Typic Dystrochrepts). Treatments including spunbonded polyester and polypropylene blankets, sewage sludge, and pine needles were applied in the late fall and compared to a check. Spunbonded polyester blankets weighing 34 to 68 g m2provided the most beneficial results. Compared to the uncovered control, bentgrass grown under the spunbonded polyester blankets generally had 10 to 20% more spring leaf moisture, up to 24% more root length, 80% more clipping(s) and up to 10 °C higher soil temperatures. This hastened the rate of spring turf green‐up by 5 to 12 days. The polypropylene blankets and pine needles also reduced winter desiccation although less consistently. Composted sludge did not. Polypropylene blankets weighing 238 g m2blocked up to 99.5% of the photosynthetically active radiation and caused less desirable color and growth when compared to spunbonded polyester.
Dwarf Bunt of Wheat in China: Potential Sites from Satellite Studies1
Authors: Trione E. J. , Hall M. J. 
Published: July 2010

AbstractCommon bunts of wheat (Triticumspecies) caused by Tilletia caries(DC.) Tul. and T. foetida(Wall.) Liro are present in China, but dwarf bunt has not been reported. Beginning in 1974, wheat shipments from U.S. Pacific Coast states to the People's Republic of China were stopped because they contained spores of the dwarf bunt fungus (Tilletia controversaKuhn), a pathogen affecting winter wheat. This quarantine against T. controversareflected a major Chinese concern that T. controversahad the potential to cause a widespread dwarf bunt epidemic of wheat in China. Thus, the objective of this study was to determine if agricultural lands in China's winter wheat region possessed an important climatic factor (30‐day persistent snow cover) regularly associated with this disease. Weather satellite based NOAA/NESDIS snow and ice charts were used to locate the snow areas occurring on agricultural lands. The agricultural lands were identified using Landsat multispectral scanner imagery. During the period November 1966 through February 1982, 11 instances of persistent snow cover were identified; these occurred in 7 out of the 16 yrs. One area had snow during only 1 yr, four areas had snow during 2 sequential years, and nine areas had snow cover during more than 1 nonsequential yr. Therefore, in China's major winter wheat region the potential sites for the dwarf bunt disease of wheat were rare in time and space, and it appears exceedingly unlikely that a widespread development of this disease could ever occur in China.
Influence of Soil Compaction on Soybean Stand, Yield, and Phytophthora Root Rot Incidence1
Authors: Gray L. E. , Pope R. A. 
Published: July 2010

AbstractSoil physical factors can influence plant growth and disease incidence. The objective of the present research was to determine if soybean [Glycine max(L.) Merr.] stand establishment and Phytophthoraroot rot incidence were influenced by soil compaction under Illinois growing conditions. Field experiments were conducted for 2 years (1983 and 1984) on a Drummer silty clay loam soil (fine‐silty, mixed mesic Typic Haplaguoll). Plots were compacted once in the spring of each year after the first disking by driving a tractor over the plots. Soil bulk density was increased significantly in both years by tractor compaction. In both years, initial stands and final stands for ‘Corsoy’, (susceptible to Phytophthora megaspermaDrechs. f.sp. glycineaKuan and Erwin) were reduced in the compacted plots. In 1983 there was no effect of soil compaction on initial and final stands for ‘Corsoy 79’ soybeans (resistant to races 1,2,3,6,7,8, and 9 of P. megaspermaf.sp. glycinea) but in 1984 final stands were lower with Corsoy 79 on compacted plots. The number of plants killed by the fungus was significantly increased by soil compaction for Corsoy in both 1983 and 1984. In 1983 there was no difference in seed yield of Corsoy 79 in compacted and noncompacted field plots. In both years the yield of Corsoy was significantly lower in the compacted plots. There was also a significant difference in yield between Corsoy and Corsoy 79 in both years in the compacted plots.
Air and Soil Temperatures during Spring Burning of Standing Wheat Stubble1
Authors: Rasmussen P. E. , Rickman R. W. , Douglas C. L. 
Published: July 2010

AbstractWinter wheat (Triticum aestivumL.) residues in the Pacific Northwest are often burned even though long‐term detrimental effects on soil properties may ensue. Better weed and disease control are cited as reasons for burning even though results have been highly inconsistent. Inadequate duration of lethal temperature or a nonuniform burn pattern may allow substantial weed, disease, and insect survival. We investigated temperature patterns during burning of 5.0, 6.3, and 6.9 Mg ha−1of wheat residue on March 21 and 6.5 Mg ha−1of residue on May 3. Wheat residue consisted of about 60% standing stubble (350 mm tall) and 40% harvested litter deposited on the surface of a coarse‐silty, mixed, mesic Typic Haploxeroll. Temperature maximum, duration, and variability below, at, and above the soil surface were recorded with copper‐constantan thermocouples. Air temperatures reached a maximum within 30 s after ignition and returned to near‐ambient level within 180 s. Maximum temperatures averaged 301, 416, and 315°C at 25, 75, and 250 mm, respectively, above the soil surface. Burning had no effect on the temperature 25 mm below the soil surface. Neither residue level nor date of burning substantially influenced temperature maximum or duration. Soil surface temperatures during burning were highly variable, seldom exceeding 120°C when the litter‐burn was incomplete, but ranging between 170 and 330°C where litter was completely burned. Substantial occurrence of surface temperatures below 120°C suggests that uniform residue distribution and complete combustion are critical for achieving temperatures capable of destroying weed seeds and disease organisms located on or near the ground.
Sharing the Available Fertilizer Rate between Two Crops in a Limited‐Capital Situation1
Authors: Isfan Daniel 
Published: July 2010

AbstractFertilizer recommendations are usually based on the maximum economic rate, which gives the greatest profit per unit area. When the capital is limited, this fertilization rate obviously cannot be applied to all crops. In this case, a method to calculate the most profitable fertilizer rates for each crop is needed. The objective of this work is to develop such a method for nitrogen (N) fertilizer applied in the same year to two different crops or else the same crop in two different crop sequences where the fertilizer needs are not the same. The shared economic rates (SR) of N for crop 1 (S1) and crop 2 (S2) can be calculated with equations and where S1and S2are shared N rates for crop 1 and 2, in kg ha−1; P1and P2are the price of crop 1 and 2, in $ kg−1; A1and A2are the areas planted to crop 1 and 2, in ha; kis the total amount of N available for A1and A2in kg; and b1, b2, c1, and c2are the regression coefficients of the quadratic production functions for crop 1 and 2 (Y= a+ bN+ cN2, where Yis the predicted yield and N the added N, in kg ha−)1).