bluuebunny/crossref_metadata_2025 huggingface dataset:
Computer Controlled Chemical Field Applicator for Research
Authors: Loussaert Dale
Published: July 2010

An automated, computer controlled sprayer was developed that interfaces experiment management with chemical application. Treatment combinations of a randomly assigned experiment can be assigned sprayer boom numbers using an IBM‐XT (compatible) computer. The sprayer boom number associated with each experimental unit is transferred to a portable computer and used as a template for sprayer control. Subsets of the information can be arranged in any order desired. As the sprayer moves across the experimental plots the computer activates the appropriate boom associated with the treatment combination assigned to each plot. The portable computer will control the sprayer in three modes: manual (the user switches the sprayer on and off between plots); semi automatic (the user starts each plot but the computer turns the booms off at the end of the plots); and automatic (the user marks the start of the first plot and the computer turns on and off each remaining plot). This system expands the utility of multi‐boom research field sprayers.
Plot Sprinklers for Irrigation Research
Authors: Eldredge E. P. , Shock C. C. , Stieber T. D.
Published: July 2010

Portable plot sprinklers were developed that allowed individual plots to be irrigated independently of other plots. Each plot sprinkler consisted of three rotary‐pendulum, square‐pattern sprinkler heads mounted on a PVC pipe frame. Plot sprinkler water output was 0.9 m3 h−l, on an area 4.6 m wide by 13.7 m long, with Cu = 80%, when operated at 86 kPa. Plot sprinklers were used to apply irrigation treatments In a randomized block design to evaluate potato (Solanum tuberosum L. ‘Russet Burbank’) tuber quality response to six levels of transitory drought stress during early tuber bulking. Yield of U.S. Number One tubers decreased and yield of U.S. Number Two tubers increased with increasing severity of transitory drought stress. Plot sprinklers allow irrigation of plots in an experiment at different frequencies or durations.
Adjustable Soil Coring Machine for Sampling in Tall Row Crops
Authors: Hatfield J. L. , Schaaf S. L.
Published: July 2010

Soil sampling is difficult when the crop canopy is tall and row width is variable between experiments. A specialized hydraulically‐driven soil sampling tractor was designed and constructed with variable wheel width and clearance height. The tractor has an adjustable wheel width from 1.6 (5.2) to 2.4 m (7.9 ft.) and clearance height from 2.2 (7.2) to 2.7 m (8.9 ft.). A Giddings hydraulic soil coring probe is front mounted on the tractor. The operator can control wheel width, height, position of the operator platform and probe, travel direction, and speed from the console. Soil cores are carried on the tractor between sampling locations. The tractor mounted system has performed well during sampling trips throughout the growing season in various row widths.
A Hydraulic Soil Sampler Providing Minimum Field Plot Disruption
Authors: Baarstad L. L. , Rickman R. W. , Wilkins D. , Morita S.
Published: July 2010

Hydraulic‐powered soil samplers speed and simplify the collection of soil cores and plant root samples. Unfortunately, the vehicle carrying a sampler often damages a large area of the crop surrounding a sampling site and compacts the soH surface. The extent of such damage often prevents the use of powdered samplers. An attachment linking a Giddings1 hydraulic probe to a knuckle boom mounted on a 3‐t truck permitted removing soil cores from small field plots with virtually no damage to the crop or soil at the sample site (except for foot traffic). The objectives of this note are to describe and illustrate the attachment and present some examples of rapid, easy collection of soil cores that it provided. The hydraulic probe, when mounted at the end of a knuckle boom, was not restricted in any of its operations.
Water Table Gradient Effects on the Performance of Diverse Cowpea Cultivars
Authors: Timsina J. , Garrity D. P. , Pandey R. K.
Published: July 2010

Cowpea sown in tropical monsoon climates is often constrained by soil saturation and a high water table during growth. We hypothesized that a strong interaction exists between cowpea maturity class and the soil water table depth regime experienced during the growing season, and that the occurrence of shallow water table depths in the dry‐wet transition period before rice and the rapid decline in water table depth in the wet‐dry post‐rice period favor early maturing cultivars. The effects of three water table regimes on the performance of 24 diverse cowpea [Vigna unguiculat (L.) Walp] cultivars was studied on a Typic Tropudalf toposequence. The water table depths in the shallow (SWT), medium (MWT), and deep (DWT) water table regimes varied between 0.06 to 0.54 m, 0.28 to 0.96 m, and 0.68 to 1.44 m in the 2 yr of dry season (DS) experiments. In the wet season (WS), the three regimes were 0 to 0.27 m, 0.30 to 0.60 m, and 0.55 to 1.05 m. Most of the early maturing cultivars exhibited their best performance in the DWT regime, but the medium maturing cultivars were superior in seed yields in all water table regimes. The mean yields of the early maturing cultivars were reduced by 49% (1986–1987 DS) and 57% (1987–1988 DS) in SWT compared to DWT. They were reduced by 50% in the 1987 wet season. The mean yield reductions for the medium maturing cultivars were 40%, 54%, and 51%, respectively, in SWT compared to DWT. Pods per plant was the yield component most affected by excess moisture. Flowering in the SWT was delayed by 4 vs 5 d (DS) and 5 vs 7 d (WS) between the early and medium maturing cultivar groups, respectively. The superiority of the medium maturing cultivars was consistent among sites with a water table within the root zone for a major portion of the crop season.
Evapotranspiration and Yield of Beans as Affected by Mulch and Irrigation
Authors: Barros L. C. G. , Hanks R. J.
Published: July 2010

Mulch (crop residue) has been reported to increase soil water storage and crop yield, and to reduce soil water stress under some conditions. However, few studies have had irrigation, and thus evapotranspiration (ET), as a variable where soil water was controlled. Therefore, a study was conducted to evaluate the effect of mulch on ET, bean yield (Phaseolus vulgaris L.), and water use efficiency (WUE), under a wide range of irrigation levels. Treatments were two cultivars (Viva‐Pink and Red‐63), two mulch rates (bare, and 7.0 Mg ha−1 of wheat straw), and six irrigation levels (from 0.0 to 288 mm) for 2 yr. Different irrigation levels were achieved by a line source sprinkler. Evapotranspiration was estimated from measurements of irrigation, precipitation, soil water depletion, and estimated drainage. Transpiration (Tr) was estimated from a function of relative yield and relative ET. Dry matter and seed yields were significantly greater for mulched than for bare plots. Mulched plots had a higher WUE (yield/ET) than did bare plots for a given irrigation level but increased as irrigation level increased. Seasonal differences in ET between bare and mulched plots were small. The yield‐ET relation for mulch was linear but was distinctly different from bare soil, indicating a different partitioning of ET into soil water evaporation (Es) and Tr. For the conditions of this experiment, mulch reduced Es by about 45 mm, at the same ET, and Tr was increased by 45 mm. However, for tbe same irrigation level, ET was lower for mulched than for bare plots, indicating that not all of the water saved went to Tr.
Sources of Variation in the Spectrophotometric Assay of Hydrocyanic Acid Potential in Sorghum Seedlings
Authors: Lee R. D. , Johnson B. E. , Pedersen J. F. , Haskins F. A. , Gorz H. J.
Published: July 2010

Spectrophotometry is a useful assay for hydrocyanic acid potential (HCN‐p) in sorghum and sudangrass [both Sorghum bicolor (L.) Moench] seedlings, but no systematic study of sources of variation in the procedure has been reported. Selfed seed was harvested from each of 12 ramets (two each from two sister plants from three low‐HCN‐p sudangrass parents), and seedlings for sampling were grown in a growth chamber, in two rows from each ramet. Seven‐day‐old seedlings were harvested and divided into two samples per row for extraction; two aliquots per extract were assayed spectrophotometrically for HCN‐p. The experiment was replicated three times. The three parents differed in HCN‐p. Rows within ramets, and samples within rows, were also significant sources of variation, but the magnitude of variance component estimates was small relative to that of the parents. Sister plants within parents, ramets within plants, and aliquots within samples were not significant sources of variation.
Using the Williams Equation to Evaluate Nutrient Uptake Rate by Intact Plants
Authors: Silberbush Moshe , Gbur Edward E.
Published: July 2010

The Williams equation uses root growth and nutrient accumulation data to evaluate nutrient uptake by plants. Accuracy of this equation depends on basic assumptions of constant uptake rate with time and space. The validity of the Williams equation and the assumptions underlying it were tested with sorghum [Sorghum bicolor (L.) Moench] plants grown in solution culture and analyzed for N, P, K, Ca, and Mg uptake. Only N and Ca influx were independent of time, as required by the equation. Influx of P, K, and Mg decreased linearly during the entire growth period. Mean root radius, which is assumed constant, decreased linearly with time. Consequently, a cautious and selective use of the equation is recommended.
Growth, Seed Yield, and Oil Content of Canola Grown under Saline Conditions
Authors: Francois Leland E.
Published: July 2010

Due to health concerns regarding saturated fat in the human diet, canola (Brassica spp.) is becoming an increasingly important source of edible vegetable oil because of its low saturated fat content. This increased demand, and the need for crop diversification, will undoubtedly promote increased acreage of canola in the western USA, where some soils are or have the potential to become saline. Salt tolerance in two canola species (B. napus L. cv. Westar and B. campestris L. cv. Tobin) was determined in a 2‐yr field plot study. Six salinity treatments were imposed on a Holtville silty clay (clayey over loamy, montmorillonitic [calcareous], hyperthermic Typic Torrifluvent) by irrigating with waters salinized with NaCl and CaCl2 (1:1 w/w). Electrical conductivities of the irrigation waters ranged from 1.2 to 9.7 dS m−1 the first year, and 1.2 to 11.5 dS m−1 the second year. Seed yield, vegetative growth, oil content, and protein content in the oil‐free seed meal were measured. Relative seed yields of Westar and Tobin were unaffected by soil NaCl and CaCl2 (1:1 w/w) 9.7 dS m−1 (electrical conductivity of the saturated soil extract: ECe), respectively. Each unit increase in salinity above the thresholds reduced the seed yield of Westar by 13.0% and Tobin by 14.3%. These results place both canola species in the salt‐tolerant category. Increased salinity did not significantly affect the oil or protein content of the oil‐free seed meal. Vegetative growth of both species was unaffected by soil salinity up to 10.0 dS m−1 and the growth decline above this threshold was 11.2% per unit increase in salinity.
Variability among Soybean Genotypes in Response to Nodulation by a Rhizobitoxine‐Producing Strain of Bradyrhizobia
Authors: Fuhrmann Jeffry J. , Vasilas Bruce L.
Published: July 2010

Nodulation by rhizobitoxine‐producing (RT+) strains of Bradyrhizobium elkanii (syn. Bradyrhizobium japonicum; DNA homology group II) has been shown to reduce shoot growth, N2 fixation, and seed yield of ‘Forrest’ soybean (Glycine max [L.] Merr.). We conducted greenhouse and field experiments to assess the frequency of these negative responses among selected soybean cultivars. In the greenhouse, 38 cultivars representing a range of yield potentials, maturity groups, and growth habits were inoculated with B. elkanii strain USDA 94 (RT+) or B. japonicum strain USDA 110 (RT−). Large differences in tolerance to nodulation by RT+ bradyrhizobia were noted, as estimated visually and by comparing shoot weights (40 d after planting) of plants inoculated with the two strains. For the field study, two tolerant (Stafford and SS FFR 565), two moderately sensitive (Pharaoh and Williams 82), and two highly sensitive cultivars (Forrest and Hutcheson) were chosen. Seeds sown to vermiculite under greenhouse conditions were inoculated with either USDA 94 or a suspension of soil taken from the study site containing the indigenous bradyrhizobia. After 23 d, the nodulated seedlings were transplanted to 1.8‐m2 field microplots. Shoots were harvested at the R7 growth stage and analyzed for various response parameters. Only Forrest, Hutcheson, and Pharaoh were significantly affected by inoculation with USDA 94, which decreased seed yield, pod number, vegetative growth, and the amount of N2 fixed. These results support the hypothesis that significant genotypic variability exists in the response of soybeans to nodulation by RT+ bradyrhizobia. The greenhouse screening procedure can provide useful predictions of the field response of tolerant and highly sensitive cultivars, but may not be accurate for moderately sensitive cultivars.
Small‐Grain Precision Planter for Dryland Experimental Plots
Authors: Botha A. H. , Purchase J. L. , Wilkins D. E.
Published: July 2010

Small‐grain stand establishment in research plots of the summer rainfall region of South Africa is a problem because of dry surface soil. A vacuum system plot planter was developed to meet these requirements. The planter has simple adjustments for changes in species, cultivars, seeding rate, row spacing, and fertilizer rate. The precision planter has fertilizer tines and modified planter units. Uniform stands are achieved with most species at seeding rates varying from 5 to 100 kg ha−1 (4.5–89.0 lb acre−11), with no restriction in plot length. The unit is easily transported and can plant in excess of 80 5‐m (16.5 ft) plots h−11.
Supplemental Boron, Boll Retention Percentage, Ovary Carbohydrates, and Lint Yield in Modern Cotton Genotypes
Authors: Heitholt James J.
Published: July 2010

Cotton (Gossypium hirsutum L.) is sometimes grown on soils with low B concentration. However, most of the literature regarding the effects of supplemental B on cotton was obtained from obsolete, low‐yielding genotypes rather than modern, high‐yielding genotypes. Therefore, the objective of this study was to determine the effects of soil‐ and foliarapplied B on leaf blade B concentration, boll retention, and lint yield of modern cotton genotypes. In 1991, three genotypes (DES 119, DES 24‐8 ne normal leaf, and DES 24‐8 ne okra leaf) and in 1992, two genotypes (Deltapine 20 and Deltapine 5415) of cotton were grown in the field on a Beulah fine sandy loam (coarse‐loamy, mixed, thermic Typic Dystrochrepts) having 0.11 mg kg−1 hot water extractable B concentration. Treatments included preplant soil and foliar (first flower to end of bloom) B (78% Na2B8O13·4H2O, 20% Na2B4O7·5H2O) applications for seasonal totals of 0, 0.89, or 1.78 (1992 only) kg B ha−1. The lowest rate of foliar‐applied B increased leaf blade B concentration from 25 to 70 mg kg−1 in 1991 and from 54 to 108 mg kg−1 in 1992. In 1992, the highest rate of foliar B applications resulted in a leaf blade concentration of 154 mg B kg−1. Soil‐applied B did not alter leaf blade B concentration in 1991, but slightly increased leaf blade B concentration in 1992 from 54 to 71 mg kg−1. Soil B concentrations were higher during the midseason than the preplant period, suggesting that preplant soil B analysis may not accurately foreshadow soil B supply during the season. Soil B or foliar B applications did not affect boll retention percentage, flower number, or lint yield in either year. Supplemental B did not affect boll distribution in 1991, but in 1992, foliar B applications increased the percentage of fruit on monopodial branches. In both years, supplemental B did not greatly affect fiber properties with the exception that supplemental B increased fiber micronaire reading of Deltapine 20 in 1992. The results suggest that modern cultivars may not always need supplemental B when soil B concentration is moderately low.
Radiation‐Use Efficiency and Grain Yield of Maize Competing with Johnsongrass
Authors: Kiniry James R.
Published: July 2010

Accurate simulation of the impact of weeds on crops requires adequate quantification of weed effects on crop biomass and on the partitioning of crop biomass into grain. The first objective of this study was to determine whether radiation‐use efficiency (RUE) values of maize (Zea mays L.) and johnsongrass [Sorghum halepense (L.) Pers.] grown in monoculture could be applied to these species grown in mixed plantings. The second objective was to investigate how maize yield and harvest index (HI) respond to johnsongrass competition. Monoculture plots of maize and johnsongrass and plots with the two species competing were established on Houston black clay (fine, montmorillonitic, thermic Udic Pellustert) in the field at Temple, TX, in 1991 and 1992. Sequential measurements of light interception (IPAR) and of biomass were used to calculate values for RUE prior to anthesis. Yield and HI of maize were measured after physiological maturity. Johnsongrass reduced grain yield of maize by 5% in 1991 and by 33 to 49% in 1992. The greater competition in the second year also reduced maize HI from 0.55 in the first year to 0.43 in the second. Values of RUE of maize and johnsongrass growing together were similar to weighted means of monoculture RUE values. The weights were the relative fraction of each species in the mixture. The measured values of maize‐johnsongrass mixtures differed from weighted means by 3 to 11% in both years.
Modifying Soil Nutrient Level Affects Soybean Insect Predators
Authors: Funderburk J. E. , Rhoads F. M. , Teare I. D.
Published: July 2010

Soil nutrients can influence the population dynamics of arthropod pests and their natural enemies. Previous research has revealed that overfertilization increases the likelihood of pest outbreak in a subsequent soybean [Glycine max (L.) Merr.] crop following winter wheat (Triticum aestivum L.). Improving biological control from natural enemies is an important aspect of integrated pest management. Our objectives in this field study were to (i) determine the effect of soil nutrition on population densities of the predators Geocoris spp. (bigeyed bugs), Nabis and Hoplistoscelis spp. (damsel bugs), and spiders (Araneae) in a soybean canopy and (ii) relate densities of each predator to pest densities and determine if previously reported effects of overfertilization on pest densities were the indirect result of influences of soil nutrients on predator populations. Soil nutrient levels were four levels of P and three levels of K and Mg. The study was conducted in 1986 and 1987. High P favored population density of damsel bug nymphs in 1986 only, but populations were not significantly affected by K or Mg. High P significantly affected population densities of bigeyed bug nymphs each year. Density estimates of spiders were significantly increased by P only in 1986. Densities of spiders were not affected by K and Mg either year. Increased pest outbreaks from overfertilization of soybean were not the result of fertility effects on population densities of these major predators.
Subsoiling and Potassium Placement Effects on Water Relations and Yield of Cotton
Authors: Reeves D. Wayne , Mullins Gregory L.
Published: July 2010

Deep placement of K fertilizer may alleviate late‐season K deficiency of cotton (Gossypium hirsutum L.) on soils adequate in surface soil K but low in subsoil K. This 2‐yr study in Alabama evaluated effects of deep tillage (in‐row subsoiling) and K fertilizer placement on yield, leaf K deficiency, soil water depletion, and stomatal conductance of cotton grown on a soil with a root‐restricting hardpan. The Norfolk sandy loam (fine‐loamy, siliceous, thermic Typic Kandiudults) soil tested medium for K in the top 15 cm and low at greater depths. Treatments were: (i) no K, no subsoiling; (ii) no K, subsoiled; (iii) surface application (84 kg K ha−1), no subsoiling; (iv) surface application, subsoiled; and (v) deep placement in the subsoiled channel. Surface application without subsoiling resulted in the greatest soil water content (0‐ to 80‐cm depth); deep placement, the lowest. Stomatal conductance was highest with no‐K, no subsoiling and lowest with K (surface or deep), subsoiled. There was no evidence of K or drought stress‐induced stomatal closure, and stomatal closure was not related to severity of leaf K deficiency. All three K treatments increased leaf K concentration at early bloom. Subsoiling without K fertilizer increased plant size and severity of leaf K deficiency; with surface K, subsoiling more than doubled total leaf area but did not affect leaf K deficiency. Within subsoiled treatments, leaf K deficiency was more severe with deep placement of K than with surface application. Subsoiling, especially with K fertilizer, maximized seed cotton yield in both years (avg. 3261 kg ha−1) but reduced stomatal conductance. Stomatal closure and premature leaf senescence are not the likely mechanism for late‐season leaf K‐deficiency in cotton. Although subsoiling was necessary to maximize cotton yields on this Coastal Plain soil with a root‐restricting hardpan, deep placement of K fertilizer was not superior to surface application.
Stomatal Response to High Evaporative Demand in Irrigated Grain Sorghum in Narrow and Wide Row Spacing
Authors: Joaquin Sanabria R. , Stone John F. , Weeks David L.
Published: July 2010

Stomatal activity of leaves can be related to factors under producer control, including row spacing and orientation. In both grain sorghum [Sorghum bicolor (L.) Moench] and peanut (Arachis hypogaea L.), evapotranspiration has been reduced with narrow north‐south row. Under high evaporative demand, this row pattern also resulted in a more efficient plant energy budget for peanut. The trigger was stomatal action (i.e., the tendency for stomates in narrow‐row plots to close earlier in the day than in wide‐row plots), with no effect from leaf water potential or soil water content. To see if high evaporative demand causes stomatal action in narrow‐row grain sorghum, two plots were planted at 0.40‐ and 1.22‐m row spacing and used through six growing seasons. Treatments were randomly assigned to plots each year. Stomatal resistance and leaf water potential were measured at half‐hour intervals; soil water content was monitored weekly, prior to irrigation. Sixty‐five days of data were classified as to evaporative demand and stomatal activity based on stomatal resistance behavior throughout the day. On 14 d, stomatal resistance was consistently higher in the narrow‐row than the wide‐row plots. Generally, these 14 d had high evaporative demand. Another 11 d showed intermediate differences, and the 40 remaining days (which included some high‐demand days) showed no significant differences. The narrow‐row stomatal closure effect was most likely to occur on days that accumulated >6 MJ m−2 of advected energy between 0730 and 1330 h apparent solar time. As with peanut, the stomatal action effect appeared to be insensitive to leaf water potential and soil water content. Narrow north‐south planting of these crops may offer some control of evapotranspiration through stomatal action. Given the similarity of stomatal action effects in the dissimilar species of peanut and sorghum, studies of row spacing and orientation vs. stomatal activity in other species seem merited.
Endophyte‐Free Tall Fescue Cultivars Grazed by Sheep: Forage Quality and Sward Characteristics
Authors: Vecellio Linda C. , Jung Gerald A. , Harpster Harold W. , Shaffer John A. , Engle Clair E. , Everhart John R.
Published: July 2010

Although much work has focused on the performance of endophyteinfected (E+), Acremonium coenophialum Morgan‐Jones and Gams, tall fescue, Festuca arundinacea Schreb.; little information is available comparing performance attributes of endophyte‐free (E−) cultivars in the northeastern USA. Five paddocks of four cultivars [‘Festorina’, ‘Johnstone’, ‘Roa’, and ‘Kentucky 31’ (KY 31)] of E− tall fescue were rotationally stocked with ewes (Ovis aries) for 2 yr. Tall fescue and weed dry matter (DM) mass, leaf‐to‐stem ratio, and tiller density were determined both pre‐and post‐grazing and sward height was measured pro‐grazing. Forage crude protein (CP), acid‐detergent fiber (ADF), neutral‐detergent fiber (NDF), and in vitro dry matter disappearance (IVDMD) were determined by near infrared reflectance spectroscopy (NIRS). Total dry mass was higher for Festorina and KY 31 than for the other cultivars. Leaf‐to‐stem ratios were similar among cultivars. Forage height was greatest for Festorina and least for Johnstone. Fescue proportion of herbage biomass was greater and weed biomass lower for Festorina and KY 31 than for Roa and Johnstone. Tall fescue proportion of herbage biomass at the end of the trial was lowest for Johnstone. Mean tiller densities were similar for all cultivars and ranged from 2060 m−2 in spring to 1260 m−2 under stockpiling in fall. Pre‐grazed herbage CP of 204 g kg−1 was similar among cultivars. Roa tended to be low and Festorina high in both ADF and NDF, and IVDMD of Johnstone was higher than Festorina. Across seasons and years, ewe liveweight gain was higher for Johnstone than for the remaining cultivars, which were similar. Gains for Group 2 (late‐weaned) lambs were lower for KY 31 and were similar for the remaining cultivars. In light of this information, cultivar as well as endophyte status should be considered in designing experiments or planning grazing systems with tall fescue.
Seed Yield Response of Perennial Ryegrass to Low Rates of Paclobutrazol
Authors: Young William C. , Chilcote David O. , Youngberg Harold W.
Published: July 2010

Lodging of perennial ryegrass (Lolium perenne L.) seed crop is a widespread problem. Crop lodging reduces seed yield and interferes with seed harvest. This study was conducted to determine if low rates of paclobutrazol [(2RS,3RS)‐1‐(4‐chlorophenyl)‐4,4‐dimethyl‐2‐(1H‐1,2,4‐triazol‐1‐yl)‐pentan‐3‐ol] influences seed yield and yield components of perennial ryegrass cv. Pennfine. Paclobutrazol was applied at either spikelet initiation or floret initiation at 0, 0.50, or 0.75 kg a.i. ha−1. Paclobutrazol delayed the onset and reduced the severity of lodging. Averaged over the application timings, the 0.5 and 0.75 kg ha−1 rates increased seed yield by 87 and 114% in 1983, respectively, and by 56 and 75% in 1984. No difference was observed between application timings in 1983, but in 1984 paclobutrazol had a greater effect in reducing lodging and increasing seed yield when applied at spikelet initiation rather than at floret initiation. Increases in seed yield were associated primarily with improvements in the number of seed set per spike, although paclobutrazol applied at spikelet initiation in 1983 also increased the number of spikes at maturity. Paclobutrazol did not affect straw weight, but increased harvest index in both years. Paclobutrazol, however, slightly reduced seed weight. We concluded that under western Oregon conditions, paclobutrazol rate as low as 0.5 kg a.i ha−1 applied at spikelet initiation can significantly reduce lodging and increase perennial ryegrass seed yield, although rates greater than 0.75 kg a.i. ha−1 may be required to achieve maximum yield.
Upland Cotton Growth and Yield Response to Timing the Initial Postplant Irrigation
Authors: Steger Adele J. , Silvertooth Jeffrey C. , Brown Paul W.
Published: July 2010

Cotton (Gossypium spp.) production in arid and semiarid regions depends on well‐managed irrigation systems for optimum yield and production efficiency. Water deficit stress early in the growing season can affect the subsequent growth and development of short‐season cotton. A 2‐yr field study was conducted in southern Arizona to determine the optimum timing of the initial postplant irrigation for a short‐season upland cotton variety based on midday leaf water potential (LWP) measurements, and to evaluate the season‐long effects of delayed irrigation on subsequent plant growth patterns. In both years, the short‐season upland variety, DPL 20, was planted into a Pima clay loam soil [fine‐silty, mixed (calcareous), thermic Typic Torrifluvent] that had received a preplant irrigation of 152 (1993) or 254 mm (1994) approximately 3 wk prior to planting. Treatments, designated T1, T2, and T3, received the initial postplant irrigation when the average midday LWP of the uppermost, fully expanded leaf measured −1.5, −1.9, and −2.3 MPa, respectively. Daily midday LWP measurements were taken using the pressure chamber technique. Soil water was measured at 25‐cm depth increments using neutron attenuation. Plant height, number of mainstem nodes, nodes above white flower (NAWF), and canopy closure were measured at weekly intervals. All treatments reached maturity, as measured by NAWF ≤ 5, at approximately the same time during the growing season. Complete canopy closure was delayed in the T3 plots resulting in reduced interception and utilization of available solar radiation early in the growing season. When treatments were initiated, approximately 84% (T1), 62% (T2), and 32% (T3) of the total plant‐available water (field capacity less permanent wilting point) was present in the upper 1.5 of the soil profile. Yields were 1263, 1244, and 1110 kg lint ha−1 in 1993 and 1229, 1176, and 1095 kg lint ha−1 in 1994 for T1, T2, and T3, respectively. Lint yields were significantly different in 1993 (P ≈ 0.001), indicating that timing the initial postplant irrigation affected plant growth and lint yield potential.
Two Methods for the Rapid Assessment of Leaf Yield of Erythroxylum Coca Var. Coca
Authors: Acock Mary C.
Published: July 2010

Methods for estimating yields of Erythroxylum coca var. coca were devised and compared. For the PCA method, yields were estimated from canopy light interception, specific leaf area (SLA), and a calibration factor. For the canopy subsample method (CSS), yield was estimated from leaf number, size, and SLA subsamples multiplied by the ratio of canopy to subsample volume. Corrected PCA overestimated yields by 9% and CSS underestimated yields by 7% for a test dataset. The CSS method requires more field time, but uses simple equipment that can be applied at any time. The PCA method requires expensive equipment and uniform light, and it cannot be used when it is raining.
Midwest Farmers' Perceptions of Crop Pest Infestation
Authors: Aref Susanne , Pike David R.
Published: July 2010

Region, soil type, and tillage are important factors in severity of crop pest infestation. This study was conducted to determine the relative importance of these factors on severity of crop pest infestation as perceived by farmers. Correlations between pests were also studied. In a 1992 survey, farmers in 12 U.S. Corn Belt states were asked to rate the severity of crop pest infestation in their fields. The categories of pests included perennial and annual weeds in row crops, insects and diseases of corn (Zea mays L.) and sorghum [Sorghum bicolor (L.) Moench], and insects and diseases of soybean [Glycine max (L.) Merr.]. Means ranked from highest to lowest in the following order: annual weeds, perennial weeds, corn and sorghum insects, corn and sorghum diseases, soybean diseases, and soybean insects. Correlation coefficients ranged between 0.47 to 0.69 among corn and sorghum diseases, among soybean insects, and among soybean diseases, and between 0.04 and 0.41 among perennial weeds. Correlation coefficients among annual weeds and among corn and/or sorghum insects spanned both of these ranges. Effects of either region and/or tillage were very highly significant (0.001), while soil type was not as significant an effect. In farmers' perceptions, weeds were the most serious pests and soybean pests the least serious pests; there was less relationship among perennial weeds than among pests in any other category; the drier western region was generally less severely infested; higher amount of conventional tillage practices produced less infestation; and differences in soil type were due to more severe infestation in loams, followed by infestation in clays, and then infestation in sands.
Seasonal Evaluation of the Root Zone Water Quality Model in Colorado
Authors: Farahani Hamid J. , Buchleiter Gerald W. , Ahuja Lajpat R. , Peterson Gary A. , Sherrod Lucretia A.
Published: July 2010

Evaluation of agricultural simulation models against field observations is needed to gauge their usefulness. This study was conducted to assess the ability of the Root Zone Water Quality Model (RZWQM) to simulate dryland and irrigated corn (Zea mays L.) production systems in semiarid eastern Colorado. The model was first parameterized for corn using field data from a single season. Different parameters were identified for irrigated and dryland corn. The parameterized model was run on independent data sets from the following year (irrigated) and different soils and sites (dryland) and model results were compared with field measurements. Differences between modeled and measured components of soil water content, evapotranspiration, grain yield and biomass, and crop N uptake ranged from 1 to 23% in the dryland study and from 1 to 28% in the irrigated study. On a seasonal basis, model estimates of seepage below the root zone were within 3% of measured values, while NO3–N leaching was overpredicted by 79%. Note that model parameterization relied solely on single‐season data. This could potentially produce bias in parameter values due to the narrowness of the prevailing conditions during that single season. For this reason and for the purpose of using the model to assess the long‐term impact of alternative practices, further work on parameterization and evaluation of the model needs to focus on using experimental observations from multiple seasons.
Quantitative Approaches for Using Color Infrared Photography for Assessing In‐Season Nitrogen Status in Winter Wheat
Authors: Flowers Michael , Weisz Randall , Heiniger Ronnie
Published: July 2010

Due to the timing and rates of N applications in wheat (Triticum aestivum L.), the potential exists for high N loading to the environment. Plant tissue tests offer growers the ability to determine in‐season N status, and to optimize N applications and N use efficiency. However, sampling and N analysis can be costly, difficult, and time consuming. Remote sensing may offer a solution to these problems. The objectives of this study were to determine (i) if remote sensing could be used to estimate in‐season N status, (ii) if within‐field calibration would improve the ability of remote sensing to estimate crop N status, and (iii) if optimum N rates could be estimated using remote sensing. Research was conducted in 1999 to 2001 at eight sites. Two sites had randomized complete block designs with variety, seeding rate, and N rate as treatments. Six sites had a single seeding rate and wheat variety. Biomass was found to influence spectral measurements of in‐season N status. A strong relationship between the normalized difference vegetation index (NDVI) and growth stage (GS)‐30 whole‐plant N concentration (R2 = 0.69) and GS‐30 N uptake (R2 = 0.61) was found. Within‐field calibration did not improve the estimation of in‐season N status by NDVI. While it was possible to use NDVI to estimate GS‐30 N uptake, predicted N fertilizer rates based on N uptake were highly unreliable. However, NDVI reliably predicted GS‐30 N fertilizer rates based on whole‐plant N concentration for wheat that had mean GS‐30 biomass values >1000 kg ha−1
Topography and Management of Nitrogen and Fungicide Affects Diseases and Productivity of Canola
Authors: Kutcher H. R. , Malhi S. S. , Gill K. S.
Published: July 2010

Successful application of precision agriculture technology requires information on crop response to many factors including fertilization and disease management. Field experiments were conducted on a hummocky landscape in the northern prairies to determine effects of slope (SL) position, N fertilization, and fungicide (FU) application on disease incidence, biomass yield, and seed yield, quality, N uptake, and recovery of applied fertilizer N for canola (Brassica napus L.). As N rate was increased, blackleg [Leptosphaeria maculans (Desmaz.) Ces. & De Not] disease incidence, biomass yield, and seed yield, protein content, N uptake, and percentage green increased while emergence, thousand‐seed weight, and seed oil content and recovery of fertilizer N declined. The response of seed yield to N fertilization was relatively greater at upper than at the lower SL position, indicating the fertilizer N requirement for optimum seed yield was less at lower (71 kg N ha−1) than upper (88 kg N ha−1) SL. The upper SL had higher blackleg incidence and seed oil content than the lower SL. Therefore, FU application to control blackleg tended to be more beneficial for high N rates at the upper SL position. Sclerotinia stem rot [Sclerotinia sclerotiorum (Lib.) de Bary] did not appear to vary between management units. The results indicate some potential to use precision agriculture based on topography to guide disease control and N fertilizer strategies although each disease must be considered individually and with consideration for other management practices and environmental conditions.
Comparison of stochastic models of rainfall processes in mountainous climatic conditions
Authors: Lee J. Y. , Han M. Y. , Kim D. K. , Ji W. H.
Published: July 2010

The main objective of this work was to find a stochastic simulation model that was suitable for designing a rainwater harvesting system for agricultural water utilization and irrigation water in a mountainous region. Several models were applied using daily rainfall data from two sites (Gangneung and Daekwanreung) to assess the accuracy and suitability of the model for simulating the daily rainfall. The amount of rainfall for the mountainous region was well described by a two-parameter gamma distribution and performed better than other distributions. However, validation tests revealed that the annual mean absolute percentage error (MAPE) was more than 10% at both locations. This result was different from some previous research in which a three-parameter mixed-exponential distribution was well described. In addition, although the exponential distribution was also well described by a second-order expression, the use of a one-parameter distribution had a simpler algorithm than the two-parameter gamma distribution and the three-parameter mixed-exponential distribution.
Assessment of the Efficacy of L-Lysine Sulfate vis-à-vis L-Lysine Hydrochloride as Sources of Supplemental Lysine in Broiler Chickens
Authors: Bahadur Vijay , Haldar Sudipto , Ghosh Tapan Kumar
Published: July 2010

In this study the effects of L-lysine hydrochloride (containing 78.8% available lysine as crystalline lysine) and L-lysine sulfate (containing 51% available lysine in bacterial cell mass) as source of supplemental lysine in broiler chickens was assessed. The basal diet was supplemented with either L-lysine hydrochloride or L-lysine sulfate to meet lysine requirement. Lysine supplementation irrespective of source improved () live weight and food conversion. Live weight and food conversion ratio of the L-lysine sulfate group was superior () to the L-lysine hydrochloride group. Supplementation of lysine to the basal diet improved breast meat yield (). Meat protein content and protein accretion increased () when L-lysine sulfate was supplemented. Nutrient metabolizability, N retention, protein utilization efficiency and live weight gain : lysine intake ratio also improved () with L-lysine sulfate. A fasting trial conducted after the completion of the feeding trial indicated that the birds receiving L-lysine sulfate retained more of their live weight than the control and the L-lysine hydrochloride dietary groups (). It was concluded that due to the retained bacterial cell mass, L-lysine sulfate may be a superior source of supplemental lysine than L-lysine hydrochloride for broiler chickens.
Image‐based assessment of natural killer cell activity against glioblastoma stem cells
Authors: Du Yuanning , Metcalfe Samuel , Akunapuram Shreya , Ghosh Sugata , Spruck Charles , Richardson Angela M. , Cohen‐Gadol Aaron A. , Shen Jia
Published: May 2024

Glioblastoma (GBM) poses a significant challenge in oncology and stands as the most aggressive form of brain cancer. A primary contributor to its relentless nature is the stem‐like cancer cells, called glioblastoma stem cells (GSCs). GSCs have the capacity for self‐renewal and tumorigenesis, leading to frequent GBM recurrences and complicating treatment modalities. While natural killer (NK) cells exhibit potential in targeting and eliminating stem‐like cancer cells, their efficacy within the GBM microenvironment is limited due to constrained infiltration and function. To address this limitation, novel investigations focusing on boosting NK cell activity against GSCs are imperative. This study presents two streamlined image‐based assays assessing NK cell migration and cytotoxicity towards GSCs. It details protocols and explores the strengths and limitations of these methods. These assays could aid in identifying novel targets to enhance NK cell activity towards GSCs, facilitating the development of NK cell‐based immunotherapy for improved GBM treatment.
Selection Rules of Transition Metal Dopants for Prussian Blue Analogs Enabling Highly Reversible Sodium Storage
Authors: Li Ling , Shen Jialong , Yang Hai , Li Zhen , Chen Zhihao , Yao Yu , Li Weihan , Wu Xiaojun , Rui Xianhong , Yu Yan
Published: May 2024

Rational element doping is demonstrated as an effective strategy to optimize crystal stability and enhance the electronic conductivity of Prussian blue analogs (PBAs) to achieve a satisfactory sodium storage performance. However, unraveling the dopant selection principles is still a big challenge. Herein, the integrated crystal orbital Hamilton population (ICOHP) function is adopted to evaluate the strength of chemical bonds of N‐transition metals (N‐TM) and guide the dopant selection. Among the series of ICOHP values for N‐TM (TM = Mn, Fe, Co, Ni, Cu, Zn), the Cu─N bond exhibits the lowest ICOHP value, which indicates that Cu doping can improve the stability of PBAs compared to other dopants. Experimentally, among TM‐substituted Fe‐based PBAs (TMFeHCFs), the as‐prepared sample with 20 at.% Cu doping (CuFeHCF‐2) exhibits the best cycling performance, with a capacity retention of 83.5% after 400 cycles at 1 C, which is consistent with the theoretical calculation results. In addition, in situ XRD and in situ, Raman reveal a highly reversible monoclinic‐cubic two‐phase conversion and redox‐active pairs, respectively. This study provides valuable guidelines for dopant selection to enhance the performance of PBAs cathodes.
Small‐Molecule Fluorescent Probes for Plant Hormones and their Receptors
Authors: Lin Zibo , Xiong Junhao , Zhou Zihao , Chen Qiong , Yin Jun
Published: May 2024

Plant hormones and their receptors play a crucial role in regulating plant growth and adapting to the stress environment. The exploration of interaction between plant hormones and their receptors is significant to comprehend the molecular mechanisms of plant growth and development, the response mechanisms of adaptation to environmental changes, and to optimize the traits and stress‐resistance of crops. Since the biosynthesis, transport, and metabolism of hormones in plants are closely relevant to spatio‐temporal changes, and their content and distribution are highly dynamic, there is an urgent need for a qualitative and quantitative tool to accurately, real‐time, and in situ monitor the dynamic changes of hormones in plants without injury. Fluorescent probes have been widely used in the sensing and imaging of plant hormones and their receptors, due to their high spatio‐temporal resolution, high selectivity, non‐invasive, high sensitivity, and tailored molecular structures. Here, this paper provides a systematical overview of the research progress in the sensing and imaging of plant hormones and their receptors using fluorescent probes. In addition, the potential prospects and remaining challenges are also discussed to design fluorescent probes with better performance and promote the development of this field.
Growth of molecular orientation during post‐process annealing of poly(lactic acid) containing a fibrous nucleating agent
Authors: Vo Hoang‐Giang Dai , Yamaguchi Masayuki
Published: May 2024

Poly(lactic acid) (PLA) is known to exhibit slow crystallization. Therefore, post‐process annealing is often performed, at which structure change is inevitable. In this paper, the structure development during annealing of PLA containing N,N′‐ethylenebis(12‐hydroxystearamide) (EBHS) is studied using extruded strands. First, EBHS, which acts as a nucleating agent, is dissolved in molten PLA, and then segregates with a fibrous shape during cooling. Next, the PLA containing EBHS is extruded, which causes EBHS fibers in the strand to orientate with the flow direction. When the strand is annealed at 100°C, amorphous PLA chains initially lose their orientation. Then, the chain orientation in the PLA strand develops because of transcrystallization from the surface of EBHS fibers that are aligned with the flow direction. As a result, the Hermans orientation function increases from 1.8 × 10−3 (before annealing) to 6.0 × 10−3 (after annealing). Moreover, the annealed PLA/EBHS strand shows less shrinkage (0.80 ± 0.19%) than the annealed PLA strand (2.04 ± 0.27%). The promotion of PLA chain orientation induced by the presence of aligned EBHS fibers can be used to control the structure and dimensional change of PLA products during annealing.
DANOISE; A 3D Printable Battery Cell for Laboratory Operando X‐Ray Diffraction and Absorption Spectroscopy**
Authors: Johansen Morten , Verdelin Jannie Kirk , Kallio Antti‐Jussi , Kessler Tommy Ole , Huotari Simo , Ravnsbæk Dorthe Bomholdt
Published: May 2024

Studying structural and electronic processes in the materials inside a battery as they occur during battery operation is key for developing novel improved materials for future generations of batteries. Such studies often entail X‐ray diffraction and absorption spectroscopy, which have so far primarily been conducted at synchrotron facilities despite the widespread use of laboratory‐based X‐ray diffraction and absorption spectroscopy for day‐to‐day characterisation. With the “Developed in Aarhus: New Operando In‐house Scattering Electrochemical” (DANOISE) cell, these experiments are brought into the laboratories making in‐house operando X‐ray diffraction and absorption spectroscopy on‐demand additions to the existing facilities. The chic and facile design of the DANOISE cell provides high quality scattering and absorption data besides providing reliable electrochemical performance. In this work, we describe the design of the DANOISE cell and demonstrate the capabilities of the cell using different commercial technologies for Li‐ion batteries and from a new Na‐ion battery electrode material.
Misuse of topical over‐the‐counter medication: A case report
Authors: Mathur Mahesh , Thakur Neha , Jaiswal Sunil , Bhattarai Nabita , Karki Sambidha , Regmi Sandhya , Paudel Supriya
Published: May 2024

Key Clinical Message

Overuse of topical medication is a national issue. Over‐the‐counter (OTC) medications are dispensed to patients directly without a physician's prescription and when used improperly without proper knowledge can lead to their misuse and toxicity.