bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recovery of Leaf Water Potential, Transpiration, and Photosynthesis of Cotton During Irrigation Cycles
Authors: Bielorai H. , Hopmans P. A. M. 
Published: July 2010

AbstractThe ability of a plant to recover from temporary and/or prolonged stress and the rate of recovery are of great importance in crop production. However, the information available on this subject is relatively scarce. A study was conducted to evaluate the recovery of irrigated cotton (Gossypium hirsutum L. ‘Acala 15–17’) following soil moisture stress of various durations through the measurements of soil moisture stress (Ψs) using 1) the soil‐moisture retention function, leaf water potential (Ψl), by pressure bomb, and 2) leaf diffusion resistance (Rl), by diffusive resistance porometer. Photosynthesis was measured by an infrared gas analyzer, and transpiration by weighing. The experiment was conducted in a controlled climate room. Leaf water potential (Ψl) was linearly related to that in the soil (Ψs) (Ψl = 0.609 Ψs − 9.77 atm). Diffusion resistance of the leaves showed a curvilinear dependence on Ψs with a marked inflection between −10 and −14 atm. Neither leaf resistance nor transpiration fully returned to pre‐stress conditions after irrigation, and even the partial recovery required several days. Continuous measurements of net photosynthesis also showed a delayed and only partial recovery from soil water stress. It is concluded that the observed reduction in dry matter increase is due mainly to the failure in net photosynthesis recovery after re‐irrigation.
Effects of Harvest Date, Plant Density, and Hybrid on Corn Grain Quality1
Authors: Cloninger F. D. , Horrocks R. D. , Zuber M. S. 
Published: July 2010

AbstractCorn (Zea mays L.) growers often question the effect of delayed fall harvest on grain quality. Various studies have reported the effect of genetic and environmental factors on the quality of grain, but few have reported on date of harvest. Therefore, the purpose of this study was to investigate the effects of harvest date, as well as planting density, hybrid, year, and their interactions on the quality of corn grain.Four hybrids were planted at 40,000, 60,000, and 80,000 plants/ha. Harvest dates were October 1, November 1, and December 1 each year of the 3‐year study (1969–71). Grain quality was measured by determining protein and oil content, 1,000‐kernel weight, test weight, and kernel hardness. Standard procedures were used for the first four variables and kernel hardness was determined on a Steinlite Model CK2 corn breakage tester.The only interactions to show significance were those of year with the other main effects. Protein content was not affected by delayed harvest, but did decline significantly with each 20,000 plant/ha increase in planting rate. Oil content varied more among hybrids (3.44 to 4.16%) than years (3.50 to 3.91%), and declined significantly as the harvest date was delayed (3.80 to 3.68%).Kernel weight and kernel breakage were closely related to the environment of the particular growing season. The range in 1,000‐kernel weight among years was 68 g, whereas the maximum differences among hybrids was 34 g. Kernel breakage, an indication of kernel hardness, increased as population was increased from 40,000 to 60,000 plants/ha. When harvest was delayed from October 1 to November 1 kernel breakage increased.This study showed that protein content was not affected by delayed harvest and that kernel breakage was more closely related to the seasonal fluctuations in environmental conditions than to the treatments imposed. On the other hand, oil content showed a 0.12 percentage point decline as harvest was delayed. This decline, although significant, probably has little meaning from the milling point of view since the oil content of corn ranges from 4 to 5% of the whole kernel and not all the oil is extracted in the milling process. However, losses associated with delays in harvest as a result of increased stalk lodging and ear droppage were of greater significance.
Soil Mn Availability to Soybeans as Affected by Mono and Diammonium Phosphate1
Authors: Randall G. W. , Schulte E. E. , Corey R. B. 
Published: July 2010

AbstractWith increasing efforts toward greater soybean (Glycine max (L.) Merr.) production, Mn deficiency undoubtedly will appear more frequently. To determine if Mn deficiency can be alleviated by locally placed common fertilizer materials, monoammonium phosphate (MAP) and diammonium phosphate (DAP) were added to a Mndeficient Sebewa loam (Typic Argiaquoll) in both greenhouse and field studies. Soil and plant analyses and soybean yields were used to evaluate the treatments.In the greenhouse, soil pH was depressed slightly and exchangeable Mn increased by the ammonium phosphate treatments. The Mn deficiency was alleviated partially by localized applications of 10 or 20 ppm P as DAP or 20 ppm P as as MAP. These treatments produced plants that were significantly larger and showed less severe Mn deficiency symptoms than plants in control pots without P added.Deficiency of Mn in the field was alleviated by P applications of 17 and 34 kg/ha either as MAP or DAP. Plant weights, leaf Mn concentrations and soybean yields from the P‐treated plots were significantly higher than those from control plots. Plant weights and bean yields from P treatments were not different from the bandapplied Mn treatment (22 kg Mn/ha). However, leaf Mn concentrations resulting from the application of 34 kg P/ha as MAP or from 17 or 34 kg P as DAP were significantly higher than from the Mn treatment.
Cold Hardening and Carbohydrate Composition of Meyer Zoysia1
Authors: Rogers R. A. , Dunn J. H. , Nelson C. J. 
Published: July 2010

AbstractThere are few reports on cold hardening in warmseason turfgrass species. The purpose of our study was to measure changes in cold hardiness and carbohydrate composition of Zoysia japonica Steud ‘Meyer’ turfgrass during fall and winter.Both rhizome and stolon tissue developed comparable levels of cold hardiness as measured by an artificial freeze test. A significant (P <; 0.05) reduction in percentage survival of tissue occurred at freeze‐test temperatures at or below −6.7 C on September 23 and Octobei 26; and −10.0, −8.9, and −12.8 C on November 30. January 10, and March 13, respectively. Total nonstructural carbohydrate (TNC) concentration of both rhizome and stolon tissue increased during September, remained relatively constant near 50% of dry weight until December, and was reduced to about 15% by March 15. Starch comprised the largest percentage of the carbohydrate fractions and closely followed TNC concentration. Total sugars increased slightly during fall, while reducing sugars remained nearly constant during the entire sampling period.
Determining Density of Maize Canopy from Digitized Photographic Data1
Authors: Stoner E. R. , Baumgardner M. F. , Swain P. H. 
Published: July 2010

AbstractPlant and soil scientists have devised many methods with varying degrees of success to determine the density of vegetative cover. Canopy density is important in estimating yield of biomass, characterizing vegetative stress, predicting soil losses from erosion, and planning resource management programs. The objective of this investigation was to examine quantitatively the relationship between the densities of maize (Zea mays L.) canopies and the energy reflected by them.Spectral and spatial data were obtained from color and color infrared (IR) photographs from 10 m above field plots of four growth stages of maize on dark and light‐colored soils.Leaf area index (LAI) measurements were made in the field. Photographs were used for determining percent ground cover 1) by a point grid technique and 2) by microdensity scanning of the three separate emulsion layers of the color photographs and digital analysis of the resulting data.A statistical pattern recognition computer program was used to determine the spectral separability of the digitized photographic data and to classify the data into two categories—green vegetation and soil.Of the emulsion layers of the color IR photographs, classification of the digitized infrared wavelength band best represented the actual percent ground cover. A plot having an LAI of 4.44 had a ground cover of 96.5% as determined by the point grid method and 93.2% by digital analysis of IR data. Classification of data from the visible red (0.59 to 0.71 μm) overestimated percent ground cover and from the green (0.47 to 0.61 μm) underestimated percent ground cover.
An Aseptic Mist Chamber System: A Method for Measuring Root Processes of Peas1
Authors: Smucker A. J. M. , Erickson A. E. 
Published: July 2010

AbstractAlthough plants have been grown with their roots in mist chambers and sterile nutrient solutions, these methods have not been combined to provide a system which permits rapid changes in the gaseous composition of an aseptic rhizosphere. The objectives of this study were to design a mist chamber system which would withstand heat sterilization, maintain an aseptic rhizosphere, permit rapid gaseous exchange without altering rootwater relationships, and permit the measurement of morphological and physiological root responses without disrupting the system.A pyrex glass mist chamber system is described which permitted a complete exchange of the root atmosphere in 5 min. Pea (Pisum sativum L.) seedlings were treated from 6 to 17 days in the aseptic mist chamber. Root respiration, root exudation, and rhizosphere volatiles were monitored. Detection limits were 1.0 ppm of ethanol, 1.0 and 0.25 μg for the TMSi amino acids and sugars.This system provides for concise control of the rhizosphere and precise measurements of root responses to environmental stresses.
Diffusion and Mass Flow of Nitrate‐Nitrogen into Corn Roots Grown Under Field Conditions1
Authors: NaNagara T. , Phillips R. E. , Leggett J. E. 
Published: July 2010

AbstractNitrate‐nitrogen, the most important source of N of non‐leguminous plants, is soluble in soil water and is transported to plant roots by both mass flow and diffusion. It is, therefore, important to evaluate the relative importance of each of these two mechanisms of transport of NO3‐N to plant roots and the environmental conditions under which each is the dominant mechanism of transport. The objective of this paper was to present measurements of plant and soil parameters necessary for estimating accumulation of N grown under field conditions with the use of a theoretical model and to compare estimates of accumulation of N in the corn plant with measured accumulation in the plant.Plant and soil parameters were measured 37, 49, 76 and 97 days after planting on corn grown under field conditions for use in the theoretical model to predict uptake of N by the roots. The plant and soil parameters measured were volumetric soil water content, concentration of NO3‐N in soil solution, porous diffusion coefficient of NO3‐N in soil, average macroscopic velocity of soil water at plant root surface, radius of root, transpiration rate, and plant root length. In the derivation of the theoretical model it was assumed that the flux of NO3‐N into the root was proportional to the concentration of NO3‐N in the soil solution surrounding the root; the constant of proportionality, k, relating these two quantities has been referred to as the “absorbing power of the root.” A linear relationship between flux and concentration was found to exist up to a concentration as high as 160 μg NO3‐N/cm3 of soil solution for corn grown under field conditions. The proportionality constant, k, was found to decrease with time and/or age of the plant; k values of 0.51, 0.35 and 0.26 cm2/sec were found for three harvest dates corresponding to 34 to 49, 49 to 76, and 76 to 97 days after planting, respectively.The errors of the predicted uptake of N as compared with measured accumulation were as large as 50% for the individual harvest periods. However, the error was greatly reduced when the predicted values and measured values were summed over the three harvest periods. In general, the predicted uptake values were smaller than the measured values when the measured values of accumulation were less than 1,200 mg of N/plant; the reverse was true when the measured values of accumulation were greater than 1,200 mg of N.
Smoothing Data with Cubic Splines1
Authors: Kimball B. A. 
Published: July 2010

AbstractAgronomic data frequently requires smoothing in order to obtain a reliable functional relationship for interpolating, predicting, or determining the rate of change of one variable with respect to another. To test whether cubic spline functions could provide satisfactory smoothing, the necessary equations were derived, computer programs written, and several sets of soil temperature and water content data were smoothed.Cubic spline smoothing displayed the following, advantages: 1) Because spline functions are defined piecewise, they can represent any variable arbitrarily well over wide ranges of the other. 2) The data can be obtained at unequal intervals, so high sampling rates can be used where changes are rapid and low rates where they are slow. 3) Additionally, the gradients derived from cubic spline functions are smoothly joined parabolas, not the abruptly joined straightline segments characteristic of parabolic spline smoothing.
A Model to Predict Winter Wheat Emergence as Affected by Soil Temperature, Water Potential, and Depth of Planting1
Authors: Lindstrom M. J. , Papendick R. I. , Koehler F. E. 
Published: July 2010

AbstractEstablishment of adequate stands of winter wheat (Triticum aestivum L.) in northwest USA is often hampered by low soil temperature or moisture, or by deep planting to reach moisture sufficient for emergence. Because of the wide variability and interactive effects among these factors, it is often difficult to predict the rate and extent of emergence of field plantings. A model was devised to predict emergence time of ‘McCall’ and ‘Nugaines’ winter wheat as a function of soil temperature between 5 and 25 C, water potential down to —10 bars, and planting depth. Predictions were reasonably good when compared with field measurements, particularly at high water potentials and with shallow planting. In general, the emergence rate progressively decreased with lowering of water potential, lowering of temperature from 25 C, or with increase in planting depth. The lower limit or minimum water potential for emergence increased with increasing temperature. Both wheats responded similarly to temperature decreases; however, the emergence rate of each variety responded differently to change in water potential. Differences in varietal response to water potential can possibly be characterized in terms of two parameters in the function describing the water potential effect on emergence.
Effect of Planting Depth, Temperature, and Cultivars on Emergence and Yield of Double Cropped Soybeans1
Authors: Stucky Donald J. 
Published: July 2010

AbstractAdequate soil moisture may not be available in the first 5 cm of soil for the germination and emergence of soybeans [Glycine max (L.) Merr.] planted immediately after wheat is harvested. Since soil moisture generally increases with depth, deeper planting may be advantageous to help insure an adequate plant population. Three experiments were conducted to determine the influence of planting depth and temperature on the emergence and yield of several cultivars of soybeans. A pot experiment conducted in growth chambers had these variables: (a) nine cultivars from three maturity groups, (b) three planting depths—5, 7.5, and 10 cm and (c) three temperatures—16, 24, and 32 C. The soil medium consisted of a mixture of silt loam, sand, and peat in a ratio of 1:1:1, by volume. The second experiment was a 1973 field experiment which was planted with a no‐till planter in 76 cm rows. The 1973 field experiment involved: (a) three cultivars in different maturity groups, and (b) three planting depths—5, 7.5, and 10 cm. A second field experiment was conducted in 1974 in which doublecropped soybeans were planted with a no‐till planter with the following variables: (a) five cultivars from three maturity groups, (b) two row widths—51 and 76 cm, and (c) three planting depth treatments—5, 7.5, and 7.5 cm covered by 5 cm of soil. Both field experiments were conducted in a Stoy series soil of the fine‐silty, mixed, mesic family in the Albaquic Fraguidalf subgroup. These experiments indicated that (a) most soybean varieties can emerge satisfactorily from depths up to 7.5 cm, providing moisture is not a limiting factor, (b) high temperatures accelerate soybean emergence and although some reduction in percent emergence occurs, it does not appear to be a prohibitive factor, and (c) the highest yields in southern Illinois were achieved with varieties from maturity groups III and IV when planted in 51 cm rows.
Effect of Increasing Foliage and Soil Reflectivity on the Yield and Water Use Efficiency of Grain Sorghum1
Authors: Stanhill G. , Moreshet S. , Fuchs M. 
Published: July 2010

AbstractThe effect of increasing foliage and soil reflectivity on yield and water use efficiency of grain Sorghum crops (Sorghum bicolor (L.) Moench.) grown under arid conditions with stored soil water only, was studied during 3 years of randomized block field experiments. Suspensions of kaolin were sprayed on the soil and/or foliage at different growth stages to select the most effective placement and timing for the treatment. Soil‐only applications were ineffective in increasing yields but canopy sprays resulted in an additional yield of 446 kg/ha, or 11% over the unsprayed controls, averaged over the 3 years of experimentation. The most effective period for foliage sprays started seven weeks after seedling emergence and ended 10 days later, immediately before the panicles emerged. During this period, known to be critical for Sorghum grain yield response to water status, the yield response averaged 2 kg grain/1 kg kaolin applied. Neither the total seasonal water use nor the rate of soil water depletion was affected by the foliage reflectance treatment.It is concluded that under arid conditions, kaolin suspensions sprayed twice on the foliage of unirrigated grain Sorghum crops during the prepanicle‐emergence stage shows promise as an effective method of increasing grain yield.
New Technique for Measuring the Water Potential of Detached Leaf Samples
Authors: Brown Ray W. 
Published: July 2010

AbstractEvaporative losses and contamination in sample disks after they are cut from plant leaves often cause errors in measurements of water potential. A new technique for collecting detached leaf disks to measure water potential eliminates most of the errors associated with other methods. The leaf cutter contains a double‐junction Peltier thermocouple psychrometer. When a leaf disk is removed from the plant, it can be sealed immediately against the cavity containing the psychrometer.
Salt Tolerance of Prostrate Summer Cypress (Kochia prostrata)1
Authors: Francois L. E. 
Published: July 2010

AbstractProstrate summer cypress (Kochia prostrata L.), a widely distributed perennial shrub in Russia, was imported into the USA to determine its potential as an acceptable forage on the western rangelands. Since considerable acreage of its possible habitat contains salt‐affected soils, a salt tolerance study was done to determine how well suited it was to these saline areas.Two accessions of Kochia prostrata L., PI 314929 and PI 358941, were tested using soil cultures in the greenhouse. Salinity levels used were 2, 7, 11, and 17 mmho⁄cm. The plants were harvested six times over a 3‐year period. Both accessions proved to be very salt tolerant but PI 358941 was significantly more productive than PI 314929 at all salinity levels. Although sodium and chloride contents approached 50 and 85 meq⁄100 g dry matter, respectively, no salt injury symptoms were visible. Sodium uptake increased proportionately with increasing salinity, whereas chloride uptake was less dependent on salt concentration and appreciably greater than that of sodium.Since both accessions proved to be highly salt tolerant, they should be well adapted for planting in the salt‐affected western rangelands.
Nitrogen Availability to Wheat as Affected by Depth of Nitrogen Placement1
Authors: Daigger L. A. , Sander D. H. 
Published: July 2010

AbstractThe availability of residual N in the root zone greatly influences the amount of N fertilizer required to optimize winter wheat (Triticum aestivum L.) yields. In order to determine the availability of N at different depths in the root zone, and N placement study was conducted in the field on two soils in western Nebraska, a deep alluvial fine sandy loam (Entic Haplustoll) and a loess‐derived silt loam (Typic Arguistoll). Ammonium nitrate was placed on the soil surface and at depths of 30, 60, 90, 120, and 150 cm. Wheat plants were harvested six times during the spring growing season to determine N uptake. Soil moisture was at field capacity in the spring when experiments were established. While N uptake tended to decrease as the depth of N application increased, total dry matter production was not affected by depth of N placement. Wheat plants easily obtained N placed at depths up to 150 cm. The results indicate winter wheat roots are mostly established during the fall growing season and are in a position to provide N early in the spring for rapid above ground growth.
Irrigated and Nonirrigated Soybean, Corn, and Grain Sorghum Root Systems1
Authors: Mayaki W. C. , Stone L. R. , Teare I. D. 
Published: July 2010

AbstractKnowledge of rooting patterns of various crops is important in designing irrigation systems and assessing water extraction capabilities. We investigated root depth and distribution under irrigated and nonirrigated conditions for soybeans [Glycine max (L.) Merr. ‘Williams’], corn [Zea mays (L.) ‘Prairie Valley 82S’], and grain sorghum [Sorghum bicolor (L.) Moench, ‘Pioneer 846’].Soil cores 6.7 cm in diam. were taken to 180 cm deep in the crop row, ¼ row, and ½ row (furrow) for each crop at physiological maturity. The cores were sectioned in 30‐cm increments and washed through 35‐mesh screen (0.73 mm opening), and the roots oven dried. The study soil was deep, barrier‐free, Muir silt loam (fine‐silty, mixed, mesic, Pachic Haplustoll).Approximately 71, 64, and 86% of the total root dry matter were in the upper 30 cm for irrigated soybeans, corn, and grain sorghum, respectively. Approximately 67, 39, and 79% of the total root dry matter were in the upper 30 cm for nonirrigated soybeans, corn, and grain sorghum, respectively. Only corn did not have roots in the 150 to 180‐cm zone. Seasonal water uses under irrigated conditions (neglecting water flux into or from the root zone) were 65 cm, 65 cm, and 53 cm in soybeans, corn, and grain sorghum, respectively. Seasonal water use was approximately 44 cm by each of the three crops under nonirrigated conditions.