bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationships Between B Deficiency Symptoms in Sunflowers and the B and Ca/B Status of Plant Tissues1
Authors: Blamey F. P. C. , Mould Diana , Nathanson K.
Published: July 2010

Sunflowers (Helianthus annuus L.) have an apparently high boron requirement but little information exists on the quantity of B necessary in plant tissues, particularly in a field‐grown crop. ‘Smena’ sunflowers grown in a field trial on an Avalon medium sandy loam (an Ultisol) showed symptoms of B deficiency in the absence of B fertilization, the most severe symptom being a malformation of the capitulum at anthesis which led to areas of no seed set. Since this symptom was apparently related to the reduced seed yield of the B deficient plants, the aim of this study was to establish relationships between the percentage deformed heads and the B concentrations and Ca/B ratios in three plant tissues, viz (i) month‐old seedlings, (ii) the topmost, mature leaf at flowering, and (iii) the seed. The mathematical relationship of best fit was established as that which minimized the residual sum of squares and maximized the correlation coefficient. In general, the B concentration proved superior to the Ca/B ratio as a measure of the status of B nutrition of the plant. Critical B concentrations, below which B deficiency symptoms increased markedly in severity and corresponding to 5% deformed heads, were calculated as 61 ppm in seedlings, 57 ppm in the leaf, and 17 ppm in the seed. It was estimated that on this soil type 1 kg borax/hit would, on average, increase the B concentration by 2 ppm, 3 ppm, and 0.2 ppm in these three tissues, respectively. The seedlings and the topmost, mature leaf at flowering provided reliable estimates of the B nutritional status of sunflowers in this study but the use of seed as an index tissue overestimated the B fertilizer requirements.
A Method for Taking Small Monoliths for Plant Root Studies1
Authors: Kauffman M. D. , Gardner E. H.
Published: July 2010

Observations of plant root growth can be important in studies involving soil‐plant relationships. A simple method for removing and exposing plant root systems was developed to study the effect of lime treatments on the root growth of alfalfa (Medicago sativa L.) and wheat (Triticum aestivum L.). A chain saw was used to remove monoliths containing partial root systems and the soil was removed from the root systems using a washing technique which consisted of a detergent pre‐treatment and subsequent oscillation of the monolith in a water bath. The monolith was mounted on a grid of nails to reduce displacement of the root system during the washing process. Using this procedure the effects of lime treatments on root growth were observed.
Cottonseed Vigor Related to Harvest and Ginning Date1
Authors: Buxton D. R. , Patterson L. L. , Taylor B. B.
Published: July 2010

We previously reported large variation in field emergence of commercially processed cottonseed (Gossypium barbadense L.) produced within a small geographical area of Arizona. The current investigation was conducted to determine if there were important management practices associated with the variation in seed vigor. An examination of the seed in question showed that much of the variation was associated with date of ginning and harvesting. Seed ginned after November were generally of low quality for planting purposes. To determine if low quality of late‐ginned seed cotton was associated with field weathering and/or the contribution of low quality seed in late matured bolls, open bolls of ‘Pima S‐5’ (G. barbadense) and ‘Deltapine 61’ (G. hirsutum L.) were harvested periodically during two autumns. The bolls were either exposed to various lengths of field weathering or had matured at different times during the harvest period. The seed was evaluated the following spring for germination, field emergence, and plant growth. Date of maturity had a greater effect on seed vigor than field weathering although both generally caused significant effects. Seed germination and emergence were influenced to a greater extent than plant height taken in the early summer or the date of initial flowering. Although the effect of date of maturity was greater than that of field weathering, the latter would be expected to affect a greater quantity of seed. This study stresses the importance of timely harvesting in order to obtain high quality planting seed.
Comparative Pre‐floral Growth of Flue‐cured Tobacco in Field and Controlled Environments1
Authors: Flynt Robin W. , Raper C. David , York Emory K.
Published: July 2010

The use of controlled‐environment facilities in agronomic research has raised questions about the comparability of plant growth in controlled and field environments. The objective of this study was to compare leaf area, leaf and stem dry weights, and stem height at several intervals during the exponential growth phase of tobacco plants (Nicotiana tabacum L. ‘NC 2326’) in field and phytotron environments. Since photosynthetically active radiation (PAR) in growth rooms usually is less than occurs in the field, the study included a range of accumulated daily PAR of 11.4, 17.9, and 25.0 E m−2day−1 in the growth rooms and 24.9 and 42.2 E m−2day−1 in the field. The lower PAR in the field was obtained by shading with open mesh fabric. For each PAR level in the growth rooms, plants were grown at day/night temperatures of 22/18 and 26/22 C.

In the growth rooms, there was not an interaction between PAR and temperature on growth characteristics. During the exponential growth phase, there was little difference between PAR levels of 17.9 and 25.0 E m−2day−1 in growth characteristics measured at the five individual sample dates or relative growth rate (RGR) and relative leaf area growth rate (RLGR) calculated over all sampling dates. There was a consistent reduction in growth when PAR was reduced to 11.4 E m−2day−1, although the differences were seldom significant.

In the comparisons of leaf weight and area growth between field and phytotron‐grown plants, growth of leaves was generally enhanced, though usually not to significant levels, for full sunlight. However, growth at the maximum growth room PAR of 25.0 E m−2day−1 tended to be greater than at 24.9 E m−2day−1 for the shaded field plots. Leaf growth at the lowest growth room PAR of 11.4 E m−2day−1 was nearly identical to that in the shaded plots. This apparent inefficiency of PAR utilization in field plots is postulated, on the basis of other experimentation, to be due to the seasonal pattern of temperature variations in the field rather than to a difference in the quality of light between field and phytotron. Stem height increased in the growth rooms at nearly twice the rate as in the field, regardless of PAR level. This difference in growth also is postulated to be the result of the temperature variations in the field.
A Methodology for Testing the Accuracy of Yield Predictions from Weather‐Yield Regression Models for Corn1
Authors: Nelson William L. , Dale Robert F.
Published: July 2010

Reliable crop‐weather‐technology models are needed for yield prediction and for the determination of climatic risks in crop production. Accurate and timely assessment of crop yields would help both government and industry allocate the food supply more efficiently. Analysis of variance (ANOVA) techniques were used to evaluate the accuracy of yield predictions for corn (Zea mays L.) in Indiana counties with four statistical models: 1) Thompson approach 2) modified Thompson approach, with a nitrogen technology term, 3) a 1974 model by Leeper, Runge, and Walker and 4) a 1975 model by Dale and Hodges. For models 1), 2), and 4), separate versions were developed with the particular series of weather and corn yield data for each county. All models were used to predict yearly average corn yields for a county with data not used to fit the regression coefficients. A significant difference among models was detected by the ANOVA. Multiple comparison tests indicated that regression models 2), 3), and 4) were more accurate than model 1). This result was attributed mainly to the handling of technology or the weather‐technology interaction effects on corn yields. The trend variables used in model 1) acted to confound weather and technology effects and create unstable regression models. Although the direct application of the results of this study is limited to Indiana, the general regression problems and methodology for testing regression models for their accuracyin predicting crop yields are believed to have universal application.
Seed Yields of Meadowfoam as Influenced by N, Seeding Rates, and Soil‐Water Table Levels1
Authors: Calhoun Wheeler , Crane J. M.
Published: July 2010

The vegetable oil from meadowfoam, Limnanthes alba var. alba, promises to be an agronomic source of several unique long‐chain fatty acids needed by industry. Studies were made on N fertility, seeding rates, and soilwater levels to determine those cultural practices necessary to maximize the production of oil bearing seeds of meadowfoam. The treatments for N fertilizer experiments consisted of two sources of N, ammonium sulfate and ammonium nitrate, and two rates for each source of N at 56 and 112 kg/ha. Seeding rates of 11.2, 22.4, 33.6, and 44.8 kg/ha were used in the seeding rate experiment. The soil‐water levels used were no drainage, soil‐water level maintained at 30.5 cm, and soil‐water level maintained at 61 cm below the soil surface, by creating hydraulically isolated soil plots. The soils used were Typic Ochraqualfs (Dayton) and Typic Olbaqualf (Concord). Seed from meadowfoam plots for all experiments was harvested with a Hege 125 self‐propelled plot combine.

The addition of N increased total seed yields. The use of ammonium sulfate as an N source as compared to ammonium nitrate depressed seed yields. A seeding rate of 33.6 kg/ha in drill rows 15‐cm apart produced highest seed yields. Lowering of soil‐water levels in soils with low permeability rates did not improve seed yields. This study indicates that meadowfoam has the potential for commercial production on poorly drained wet soils in high winter rainfall areas of Oregon.
N Losses in Irrigation Return Flows from Flooded Rice Plots Fertilized with Ammonium Sulfate1,2
Authors: Bilal I. M. , Henderson D. W. , Tanji K. K.
Published: July 2010

Losses of N from fertilized croplands are of concern from standpoints of fertilizer use efficiency as well as potential water pollution. Field experiments were conducted to evaluate the discharge of inorganic N in surface irrigation runoff and seepage in 7.6 ✕ 67 m test plots cropped with paddy rice (Oryza sativa L., cultivar Earlirose). Cultural practices commonly used in rice production in California were imposed on three plots and extensively monitored from planting to harvest. Plots 1 and 2 were continuously flooded throughout the growing season while Plot 3 was oncedrained in the 5th week after planting for a 1‐week period. Granular (NH4)2SO4 was applied at a rate of 168 kg N/ha to all plots but the mode of application and timing differed. In Plot 1 the fertilizer was partly soil‐incorporated and partly soilbroadcast before seeding and flooding. In Plots 2 and 3, 112 kg N/ha was soil‐incorporated before planting and 56 kg N/ha was top‐dressed in the floodwater in the 6th week after planting.

The seasonal water application varied from 454 to 530 cm of which 104 cm was lost as evapotranspiration, 204 to 219 cm as surface runoff, and, by difference, 128 to 222 un as seepage losses. The total seasonal losses of N from both the irrigation runoff and seepage were 18.6, 36.4. and 30.2 kg N/ha for Plots 1, 2, and 3 or 11, 22 and 18% of the applied fertilizer, respectively. The seep age losses were 45, 61, and 70% of the total seasonal N losses in Plots 1, 2, and 3, respectively
In‐Furrow Water Injection for Improving Cotton Stand Establishment1
Authors: Fowler J. L.
Published: July 2010

Successful stand establishment is essential to cotton (Gossypium spp.) production efficiency as it affects yield, earliness, weed control, and harvesting efficiency. Availability of soil moisture to the germinating seed is one of the most critical factors affecting stand establishment. In‐furrow water injection is a method of applying supplemental moisture to the soil in contact with the seed by injecting a small stream of water into the seed furrow at planting. The purpose of this study was to evaluate in‐furrow water injection as a means of enhancing stand establishment by improving soil moisture conditions surrounding the germinating seed. Several water injection treatments were compared with conventional planting methods over a period of four years. Four water injection treatments (water injection at rates of 94, 187, 281 liters/ha, and a combination of water injection at 94 liters/ha and soil capping) were compared with three conventional planting methods (soil capping, post‐plant irrigation, and a check planting into seedbed moisture) over three planting dates in 1974 and 1975. In 1974, water injection increased stand counts in a linear manner up to 82%, over that of the check. In 1975, a differential treatment response occurred among planting dates but the highest water injection rate improved mean stand count by 33%. Seedling vigor was not affected by treatment. Both earliness and yield were positively correlated with stand count in 1974 in all planting dates but only in the second planting date of 1975. Water injection resulted in mean lint yield increases as high as 41%, in 1974 and 26% in 1975.

In 1976, the effect of water injection treatments on stand count were compared with a check and a soil capping treatment over several planting dates as seedbeds progressively dried out. Two combination soil capping and water injection treatments of 94 and 187 liters/ha were added in 1977. Water injection at 187 liters/ha and above generally resulted in stand counts significantly better than that of the check and comparable to that of the soil capping treatment.
Comparison of the Hydrocyanic Acid Potential of Sorghum Seedlings and Tillers1
Authors: Haskins F. A. , Gorz H. J. , Nielsen R. L.
Published: July 2010

The usefulness of seedling assays for predicting the hydrocyanic acid potential (HCN‐p) of older plants of sorghum [Sorghum bicolor (L.) Moench] has been questioned. In this study, first leaves of chamber‐grown seedlings were compared with young leaves of field‐grown tillers by means of the spectrophotometric assay of p‐hydroxybenzaldehyde as an indicator of HCN‐p.

Absorption spectra of seedling and tiller leaf extracts indicated that the spectrophotometric method was more reliable with the seedling extracts. However, highly significant correlation coefficients were obtained in most comparisons of seedling HCN‐p and tiller HCN‐p. The r values varied greatly, depending to a considerable extent on whether the calculations were based on individual plant values, plot means, or cultivar means. With plot or cultivar means as the basis of calculation, r values in the range of 0.8 to 0.9 were not uncommon. It was concluded that assay of young seedlings with this method is useful in sudangrass [S. sudunense (Piper) Stapf] and sorghum breeding programs in which decreased HCN‐p is an objective.
Classification of Land Use and Crop Maturity, Types, and Disease Status by Remote Reflectance Measurements1
Authors: Tinker R. W. , Brach E. J. , LaCroix L. J. , Mack A. R. , Poushinsky G.
Published: July 2010

Remote sensing techniques supply useful crop information in large area crop survey programs. In such programs, however, the spectral and spatial resolution, measurement geometry, and environmental correction cap abilities have been limited by the fixed and truly remote nature of the sensor platform. To extend the applications of existing systems, or to use new systems, some workers have started small‐scale, ground‐based programs, such as the one described in this paper. The purpose of the experiment was to classify land use categories, crop maturity, type, and disease status by discriminant analysis of high resolution, normalized visible (350 to 750 nm) and infrared (750 to 1,850 nm) spectral reflectance data which were acquired, at an oblique angle, from field plots of sod, soil, and various cereal and broadleaf crops throughout the 1976 growing season. Biological data (plant heights, growth stages, leaf chlorophyll) were acquired concurrently with plot spectral measurements so that the results of the classifications could be explained in term of plot development or condition. Land use categories (sod, soil, crop), stages of crop maturity (vegetative, flowered), crop type [rapeseed (Brassica napus L. and B. campestris L.), fababean (Vicia faba L.), soybean (Glycine max L. Merr.), and cereals], and disease status (diseased or healthy cereals) were classified from the spectral data with 95.2, 93.3, 90.7, and 67.9% accuracy, respectively. The accuracy of classification for specific cereals was low [wheat (Triticum aestivum L, T. durum L.), 53.5%; oats (Avena sativa L), 67.7%; barley (Hordeum vulgare L.), 50.0%]. Partially due to stress, the growth habit and, therefore, reflectance of these crops was similar. The results of the spectral classifications were supported by trends observed in plot development or condition. Thus, it was possible to discern land use categories, general crop maturity and specific or general crop types from the analysis of remotely acquired reflectance data. Such parameters would supply useful information in a functional crop reporting system.
Herbicide Applications in Tillered Winter Wheat for Doublecrop Soybean Weed Control1
Authors: McHarry M. J. , Kapuśta George
Published: July 2010

Effective, doublecrop soybean [Glycine max (L.) Merr.] weed control usually requires a foliar‐active herbicide to control emerged weeds and one or two residual herbicides to control those that emerge after planting. This combination is expensive in relation to the narrow profit margin frequently experienced. If timely rainfall does not occur shortly after application, poor weed control may occur, resulting in reduced soybean yields. Field studies were conducted on a Weir silt loam (fine, montmorillinic, mesic Typic Ochraqualfs) to evaluate alternative methods of herbicidal weed control in doublecrop soybeans.

Oryzalin (3,5‐dinitro‐N4, N4‐dipropylsulfanilamide) and USB 3153 (N3,N3‐di‐N‐propyl‐2,4‐dinitro‐6‐trifluoromethyl‐M‐phenylenediamine) applied after the winter wheat (Triticum aestivum L.) was fully tillered but prior to the jointing stage (full‐tiller) did not cause any visual injury or yield reduction any of the 3 years of the study. Oryzalin at 2.8 kg/ha in 1976 and at 1.68 kg/ha in 1977 and 1978 controlled at least 85% of all weeds and volunteer wheat in the doublecrop soybeans that followed the wheat harvest. USB 3153 applied at 1.12 kg/ha in 1977 controlled more than 85% of the large crabgrass [Digitaria sanguinalis (L.) Scop.], ivyleaf morningglory (Ipomoea hederacea), and Pennsylvania smartweed (Polygonum pennsylvanicum L.) but common ragweed (Ambrosia artemisiifolia L.) and volunteer wheat control was not acceptable (<80%). In 1978, USB 3153 at 0.84 and 1.12 kg/ha controlled 95% or more of all weeds and volunteer wheat. Herbicides applied after doublecrop soybean planting provided acceptable weed control in 1976 and 1977 but poor control in 1978. These results indicate that oryzalin and USB 3153 applied over‐the‐top of tillered wheat provide good weed control in doublecrop soybeans and do not affect wheat yields at rates needed for acceptable weed control. Similar studies are needed at other locations to fully evaluate these treatments under different soil and environmental conditions.
Sod‐Seeding Bahiagrass in Winter with Three Temperate Legumes1
Authors: Kalmbacher R. S. , Mislevy P. , Martin F. G.
Published: July 2010

Bahiagrass, Paspalum notatum Flügge, is the major pasture grass in Florida and constitutes large hectarages in other Southern states. The species produces little forage during winter, thus overseeding with temperate legumes could be of great value to cattlemen. This experiment was designed to define the problems and potential of sod‐seeding temperate legumes in bahiagrass.

At the Ona Agricultural Research Center in south Florida, red clover (Trifolium pratense L.) and ladino clover (T. repens L.) were seeded in 1976, and red and ladino clover and alfalfa (Medicago sativa L.) were seeded in 1977 by a Zip sod‐seeder or a disk and broadcast method (D+B). The following herbicides (active rates kg/ha): 0.56 paraquat, (1, 1' dimethyl‐4, 4' bipyridium dichloride) 2 days before seeding, with sod burned at seeding (1976); 0.28 paraquat desiccation and burn (1977); 0.14 paraquat desiccation and burn (1977); 0.56 paraquat at seeding (1976); 0.28 paraquat at seeding (1976 and 1977); 2.49 dalapon (2, 2‐dichloropropionic acid) (1976); 1.66 dalapon (1977); 2.49 dalapon, 13 days before seeding with 0.28 paraquat at seeding (1976); and no herbicide (1976 and 1977) were used to control sod growth.

The 2‐year average number of legume seedlings/m3 was 103 in the D+B seeding method vs. 49 in the Zip seeded plots. Paraquat‐burn treated plots averaged 131 seedlings/m3 while all other herbicide treatments averaged 64. Legume dry matter yield was 6,130 kg/ha in the D+B plots vs. 4,500 kg/ha in sod‐seeded plots. Yields averaged 6,740 kg/ha in paraquat‐burn plots vs. 4,630 kg/ha in all other herbicide treatments. Crude protein and IVOMD in the D+B plots averaged 15.2 and 62.5%, respectively, vs. 14.0 and 60.6%, in Zip‐seeded plots. Paraquat‐burn treated plots averaged 15.2 and 63.2% crude protein and IVOMD, respectively, vs. 14.4 and 60.8% in other herbicide treatments.

Alfalfa and red clover have considerable potential for providing high yield and quality forage when overseeded in bahiagrass. Removal of competition before seeding, as was done with the paraquat‐burn treatments or the D+B seeding method, was more valuable than suppressing bahiagrass growth after seeding.
Shading and Temperature as Environmental Factors Affecting Growth, Nodulation, and Symbiotic N2 Fixation by Soybeans1
Authors: Trang Kry M. , Giddens Joel
Published: July 2010

Soybeans [Glycine max (L.) Merr.] are subjected to varying amounts of light and temperature changes when grown in the field. A study was made on the effect of shading and different temperatures of the root medium upon growth and N2 fixation of soybeans. Four shading treatments (0, 18, 40, and 62%) were imposed by screen cloths and two fertilizer N levels were used. Soybeans were also grown with four root temperatures (15, 20, 25, and 30 C) and four fertilizer N rates (0, 15, 30, and 45 ppm N). Growth, total N, nonstructural carbohydrate, nodule count, and nodule mass were determined on all experiments and, in addition, acetylene reduction was done on the shading experiment.

Plants with no shade produced more dry matter and had higher N content, higher nonstructural carbohydrate, higher nodule mass and number than when shaded. Total nodule activity (acetylene reduction) was greatest at 18% shading, however. Fertilizer N increased nonstructural carbohydrate and specific nodule activity but decreased nodule number and mass, and total nodule activity.

Temperature increase from 15 to 30 C resulted in an increase in relative growth rate and N content of plant tops, whereas total N and nonstructural carbohydrate in roots was decreased. There was no significant effect of increasing temperature upon growth of roots or nodule number or nodule mass. The N content of plant tops was increased while nodule number and nodule mass were decreased by fertilizer N application.

The most significant finding was that 18% shading produced the highest acetylene reducing activity of soybeans.
Sugarbeet Quality as Related to KCl Fertilization1
Authors: Ludwick A. E. , Gilbert W. A. , Westfall D. G.
Published: July 2010

Excessive available soil N decreases sugarbeet (Beta vulgaris L.) quality. The chloride‐nitrate uptake antagonism offers a possible mechanism for reducing the amount of NO3− absorbed by sugarbeets. The objectives of this study were to evaluate the potential of KCl fertilizer applications for reducing plant absorption of NO3− and its subsequent effect on sugarbeet production parameters, especially quality.

Experiments using six rates of KCl (up to 896 kg/ha of K and 814 kg/ha of Cl) were conducted on five farm sites in northeastern Colorado during 1977. The experimental sites were chosen so they were high in residual soil NO3− or had a history of producing low‐quality sugarbeets. All soils tested high in available K+.

Fertilization with KCl had only minor and occasional effects on depressing NO3− concentrations in petiole samples taken on three dates during the season. Root thin juice Cl− content was increased at three locations; effects of fertilization on other quality components (K+, Na+ nitrate, α‐amino N, sucrose, and purity) were mostly not significant (P≤0.10). Initial levels of soil K+ and Na+, and soil Cl− plus irrigation water Cl− were positively related to these constituents in the root thin juice. Sucrose was inversely related to soil NO3−. Fertilizer treatments did not significantly (P≤0.10) affect yield, sucrose, purity, or recoverable sugar of the crop at any location. The lack of appreciable treatment effects is attributed, at least in part, to high levels of available soil K+ and Cl−, plus a large Cl− contribution from the irrigation water.
Perennial Irrigated Pastures. III. Beef Calf Production from Irrigated Pasture and Winter Annual Range1
Authors: Raguse C. A. , Hull J. L. , Delmas R. E.
Published: July 2010

Irrigated pastures in the Western arid and semi‐arid regions provide support to the beef cattle industry through the maintenance of beef cow herds and the production of calves. Increasingly unfavorable production economics, including the rising cost and logistical difficulty of seasonally moving cattle from seasonal range to other pastures (e.g., high mountain Federal grazing allotments), necessitate evaluation of management options which permit increased stocking rate and year‐around home ranch operation.

The objective of this study was to compare simple (range‐only, yearlong) and complex [improved range and irrigated pasture plus winter supplementation with alfalfa (Medicago sativa L.) cubes] systems for beef calf production using a fall calving (November‐December), early summer weaning (May‐June) reproduction cycle.

In the complex system, cleared and reseeded range was used (winter) an average (4 years) of 6 months per year at a stocking rate of 2.2 ha/cow (2.8 AUM/ha). Irrigated pasture was used (summer) an average of 6 months per year at a stocking rate of 0.5 ha/cow (10.3 AUM/ha). Alfalfa cube supplement was fed (about 1 kg/ha per day) during fall and winter. In the simple system, cleared range was used yearlong at an average stocking rate of 5 ha/cow (2.4 AUM/ha). No supplements were fed except during the last year when drought prevailed. An average of 70 kg calf/ha was produced in the complex system. Average birth weight was 34 kg and average daily gain (ADG) to 205 days was 0.76 kg. In the simple system, comparable values were 37.5 kg calf/ha, 32 kg birth weight, and 0.75 ADG. Birth weights and ADGs were not significantly different between systems. Average cow weights reflected seasonal changes in forage availability and quality. Cows in the simple system tended to lose weight more consistently during the months July. October than did those in the complex system, which, instead, more consistently lost weight during the months November‐March. Economic return was similar but low in both systems. While total land per cow/calf unit was less for the complex system and total investment higher for the simple system, operating costs, depreciation, and interest were higher for the complex system.

It appeared that second and third trimester cow stresses, as evidenced by negative bodyweight changes, did not adversely affect calf birth weights and ADG, at least at the levels found under these experimental conditions.
Stalk and Sugar Yield of Sweet Sorghum as Affected by Spacing1
Authors: Broadhead Dempsey M. , Freeman Kelly C.
Published: July 2010

Sweet sorghum, Sorghum bicolor (L.) Moench, is a potentially renewable source of biomass, sucrose, and other fermentable sugars. Limited data are available on the influence of row width, plant arrangements within the row, and row width × plant arrangement within the row interaction on stalk and sugar yield. These field experiments were conducted from 1967‐1972 to determine the influence of row width and arrangement of plants within the row on gross and stripped stalk yield and juice quality of 'Rio' sweet sorghum. Four plant arrangements within each row, one, two, three, and four plants in hills spaced 15, 30, 45, and 60 cm, respectively, were planted on 52.5 and 105‐cm‐width rows. Narrow rows (52.5 cm) resulted in higher yields of gross and stripped stalks, and sugar per ha than conventional rows (105 cm). Plants from narrow rows were inferior to those from conventional rows in juice Brix, sucrose, purity, and yield of sugar per ton of stalks. Plants grown on narrow rows weighed less, contained less juice, and lodged more readily than those grown on conventional rows. Plant arrangement within the row did not significantly affect yield of gross stalk, stripped stalk, sugar per ton of stalks, and sugar per ha or juiciness, Brix, sucrose and purity. The width‐of‐row × plant arrangement interaction was highly significant only for stalk weight. Stalk weight was not affected by plant arrangement on narrow rows, but increased as the space between hills increased from 15 to 30, 45 or 60 cm on conventional rows.

Since the narrow rows produced higher yields of stalks and sugar than conventional rows, planting sweet sorghum on narrow rows appears to be an effective method for increasing yield of total sugar per ha.
Productivity ‐ Leaf Nutrient Content Relationships Among 10 Virginia Peanut Genotypes1
Authors: Hallock D. L. , Coffelt T. A.
Published: July 2010

Genotypes are known to differ in nutrient requirements. If there is a trend between productivity and the concentration of nutrients in peanut (Arachis hypogoea L.) foliage, this information may be useful in fertilization practices. Field studies were undertaken on Ruston and Woodstown loamy fine sands in 1976 and 1977, respectively, to provide a profile of the contents of P, K, Ca, Mg, B, Mn, Zn, and Cu in peanut leaf petioles and blades of 10 peanut genotypes sampled at mid‐season and maturity. These contents were correlated to crop value, to determine significant relationships.

Leaves of 'Florigiant' generally were higher in Mg, Zn, and Cu, 'GA C194 V‐VV' in Ca and Mn, 'PI 366048' in P, 'NC 3033' in K and 'Early Bunch' in B than other genotypes. Contents of Ca, B, Mn, and Zn in leaves of NC 3033, Mg and P in 'UF 714021', Zn and Cu in Early Bunch, Cu and P in 'GK 3', K in PI 366048 and 'PI 370327', and P in 'NC 6' were generally lower than in other genotypes.

One or more of the 64 simple correlations involving each nutrient was significant, except for Zn. Most occurred in 1976 data, a more productive year. The closest relationships were between crop value and contents of K, Ca, or Mn in mature leaf blades. Genotypes with higher crop value were somewhat higher in Ca, Mg, Mn, or B (in blades) and lower in K, P, B (in petioles), or Cu (in blades). Among the new genotypes studied, the K, Ca, and Mn fertilization requirements of NC 3033 may differ from most of the others.
Yield and Oil Content of Large and Small‐Seed Rai‐Mustard1
Authors: Ahmed S. U.
Published: July 2010

Three cultivars of rai‐mustard (Brassica juncea L. var. Rai) were studied to determine the effects of seed size on yield, yield components, and seed oil content. Seeds were screened to obtain small and large seeds, and were grown in the field at the Univ. of Kuwait, Kuwait, in 1978. At maturity, 20 plants were randomly‐selected in each row and data were recorded on an individual plant basis. Highly significant differences in character performance, except for number of days‐to‐flowering and maturity, were observed between plants developed from large and small seeds. The large seeds produced plants with a larger number of primary and secondary branches per plant, more pods per plant, larger pods, heavier seeds, higher seed yield per plant, and higher percentage seed oil content than those developed from the smaller seeds, but had relatively fewer seeds per pod. Uniform seed size is important for agronomic and genetic studies in rai‐mustard.
Construction of Serviceable, Fast Response Tensiometers from Porous Ceramic Tubes1
Authors: Nelms L. R. , Spomer L. A.
Published: July 2010

Tensiometers are widely used in commercial and research applications where in situ soil water status must be monitored. Tensiometers in these situations have the disadvantage of requiring frequent servicing to remove gas bubbles and having relatively slow response times. In research where a large number of tensiometers is required to adequately monitor changes in soil water status, easily serviceable, fast response tensiometers are essential. This note describes the construction and operation of one such tensiometer system which proved useful in studies of the water relations of transplanted container soils.
Ammonia Exchange at the Land Surface1
Authors: Lemon Edgar , Van Houtte Raymond
Published: July 2010

Studies of NH3 exchange between plant leaves and air have mostly been made in controlled chambers where the concentrations were far above the ambient atmospheric levels usually found in nature. Under such conditions leaves act as an infinite sink for NH3. More recent controlled chamber studies, however, have shown NH3 evolving from leaves when concentrations were nearer to those of the atmosphere. In this study we measured both NH3 absorption and evolution by vegetation under field conditions using micrometeorological techniques where vertical profiles of wind and NH3 are measured. Both evolution and absorption strongly suggest that plants have a compensation point for NH3. Data are presented for fields of quackgrass (Agropyron repens L.), soybeans (Glycine max L. Merr.) and alfalfa (Medicago sativa L.). Computer simulation confirmed that vegetation exchange is concentration dependent. We speculate that plants (and soil) keep atmospheric NH3 in check, at low concentrations, with winds moving it from N rich to N poor ecosystems. Dispersed sources of NH3 from crop lands are probably increasing due to more fixed N in farming. Thus the added NH3 due to man's activity probably increases the net global biosphere uptake of both N and C.
Yield and Composition of Orchardgrass, Tall Fescue, and Reed Canarygrass Mixtures1
Authors: Sheaffer C. C. , Hovin A. W. , Rabas D. L.
Published: July 2010

Mixtures of orchardgrass (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.), and reed canarygrass (Phalaris arundinaceae L.) may provide yield and utilization advantages over monocultures. Our objectives were to determine the forage production and relative competitiveness of the three species grown alone and in binary and ternary mixtures.

In two field studies each at two locations, we compared orchardgrass (O) with reed canarygrass (R) seeded alone and in binary mixtures (Exp. 1) and orchardgrass, tall fescue (F), and reed canarygrass sown alone and in binary and ternary mixtures (Exp. 2). Species competitiveness was studied in the glasshouse where individual plants of orchardgrass, tall fescue and reed canarygrass were grown alone and in binary and ternary mixtures within circular rows 4, 8, 15, and 30 cm from the center with 12 plants established per row and maintained at two soil moisture regimes.

Mixture yields were never significantly greater than those of reed canarygrass, generally the highest yielding species in monoculture. Yield differences between tall fescue and orchardgrass in monoculture were usually nonsignificant. Yields of mixtures containing reed canarygrass were generally not significantly different but were greater than O:F binary mixtures. In Exp. 1 and 2, yields of O:R and O:F:R mixtures were significantly greater than those of orchardgrass in monoculture. Under low soil moisture conditions in the glasshouse and in the field, no significant mixture yield differences occurred, but in Exp. 2 with adequate soil moisture, reed canarygrass had significantly higher summer yields than did the two other species.

In field studies, orchardgrass seedlings were most aggressive at establishment; however, in Exp 2 reed canarygrass became the dominant species by the final harvest. In the glasshouse, orchardgrass became the most aggressive species by the final harvest. Tall fescue was the least competitive species in all studies. Mean yields of within‐ and alternate‐row mixtures were not significantly different. Inclusion of reed canarygrass in mixtures with orchardgrass or tall fescue increases production particularly during the summer. If established successfully, reed canarygrass will become the predominant species in these mixtures.
Influence of Differential Phosphorus Accumulation on Corn Stalk Rot1
Authors: Porter R. M. , Ayers J. E. , Johnson M. W. , Nelson P. E.
Published: July 2010

Stalk rot of corn (Zea mays L.) is a disease complex that appear to be affected by the plant's mineral nutrition status. Two inbred limes differing in P accumulation, their Fl hybrid, and the resulting high and low Paccumulating populations reselected from the segregating generation of the Fl hybrid were grown in the field in 1976 and 1977 in order to determine the effect of differential P accumulation on several stalk rot parameters. Plants of each entry were inoculated with either Fusarium moniliforme Sheldon emend Synd. & Hans. or Gibberella zeae (Schw.) Petch using a toothpick on which the pathogen was growing. At 14, 28, and 42 days after inoculation, measurements of rotted internodal tissue were obtained. The largest amount of stalk rot occurred in the low Paccumulating population. The dry weights, crushing strengths, and rind thicknesses of noninoculated stalk sections of each entry were significantly higher in the high P‐accumulating population than in the low P‐accumulating population in both years. Greatest weight loss after incubation with either F. monilliforme or G. zeae in closed containers for 30 days occurred in the low Paccumulating population. The highest incidence of lodging occurred in low P‐accumulating populations. Differential P accumulation appears to influence lodging potentials of these populations mainly through its effect on stalk quality.
Sample Contamination from Prior Plots with a Small Plot Combine1
Authors: McCauley Garry N.
Published: July 2010

The magnitude of sample contamination of a modified Suzue model CP370C combine (Suzue Agricultural Machinery Co. Ltd., Japan)8 was determined for plot lengths of 1.5, 3.0, 4.5, and 6.0 m of ‘Labelle’ rice (Oryza sativa L.).

Treatments consisted of four plots, dyed with red, green, and purple Rhodamine dye, and the fourth plot left undyed. Plots one, two, and three were cut and discarded. Plot four was cut and 10 subsamples of 100 seed each were taken to determine percent red, green, and purple seed.

Sample contamination ranged from 9 to 20% as plot length decreased from 6 to 1.5 m. Contamination varied inversely with proximity and plot length. Rice research plots which are normally 4.5 to 6 m would result in a sample contamination of 9 to 12% with this combine.
Protein, Oil, and Energy Yields of Sunflower as Affected by N and P Fertilization1
Authors: Blamey F. P. C. , Chapman J.
Published: July 2010

Relatively little information exists on the N and P needs of sunflower (Helianthus annuus L.) on infertile soils in non‐traditional production areas. The effects of four levels each of N (0 to 180 kg/ha) and P (0 to 60 kg/ha) applied to a thermic Typic Rhodustult were evaluated over three seasons. In all seasons there were highly significant seed yield responses to N and P a plied. The nature of the N ✕ P interactions indicated a greater response to N fertilization where P had been applied than in the absence of P fertilization. Maximum seed yields of up to 2,600 kg/ha were four to 13 fold higher than yields in the absence of applied N and P. Protein level in the seed was increased by N but decreased by P fertilization, the opposite effects being generally observed with respect to the oil. Nitrogen and P fertilization markedly increased the protein and oil yields, the N ✕ P interactions indicating that P fertilization was necessary for maximum response to applied N. The ratio of seed N to fertilizer N decreased with increased N fertilization but increased with increased P applied. The food energy yield and energy production efficiency of sunflower increased markedly with both N and P fertilization.
Interference Between Oats and Alfalfa in Mixed Seedings1
Authors: Nielsen R. L. , Stuthman D. D. , Barnes D. K.
Published: July 2010

Oats (Avena sativa L.) are frequently used as a companion crop for the establishment of alfalfa (Medicago sativa L.) in the Upper Midwest of the United States. Unpublished observations from research in Minnesota suggested that some level of interference might be occurring between the two species. The objectives of this research were to determine if companion cropping affected oat grain yield and subsequent alfalfa forage yield under field conditions and to identify cultivar combinations that exhibited either interference or tolerance for each other.

Five oat cultivars (‘Multiline E‐77’, ‘Froker’, ‘Lang’, ‘Noble’, and ‘Stout’) and five alfalfa cultivars (‘Agate’, ‘Cody’, ‘DuPuits’, ‘Iroquois’, and ‘Washoe’) plus an experimental alfalfa population (MN Allelopathy) selected or its allelopathic potential on maize (Zea mays L.) were seeded in a split‐split plot design at two locations in 1978 and three locations in 1979. Oats and alfalfa were harvested for grain and for second‐year forage production, respectively.

Oat grain yield changes across all oat and alfalfa cultivars caused by alfalfa ranged from a 1.56 quintals/ha reduction at St. Paul, Minnesota, to a 1.65 quintals/ha increase at Waseca, Minnesota. Alfalfa yield in the year after establishment was reduced by oats by 0.44 metric ton/ha/cutting at Rosemount, Minnesota, and 0.19 metric ton/ha/cutting at Waseca, Minnesota. Across all environments and oat cultivars, only the MN Allelopathy alfalfa selection significantly reduced oat grain yield. Significant grain yield reductions were also observed in three oat‐alfalfa cultivar combinations: Noble/Cody, Stout/MN Allelopathy, and Lang/Iroquois. The results indicated that interference existed between some oat and alfalfa combinations in some companion cropping systems.
Desiccation, Temperature, and Degree of Dormancy of Sprigs Influence on Establishment of Coastal Bermudagrass1
Authors: Chamblee Douglas S. , Gooden DeWitt T.
Published: July 2010

‘Coastal’ bermudagass [Cynodon dactylon (L.) Pers.] is one of the most important forages in the southern United States. Frequently, poor stands are obtained and this may be related to the many different procedures used in handling and planting bermudagrass vegetatively. The objectives of this study were to determine if its establishment from sprigs was influenced by: (1) temperature and time of desiccation exposure of rhizomes with and without roots attached; (2) planting placement, degree of dormancy, size of sprigs, and irrigation.

Seven experiments were conducted for 2 years at two locations. Doimant or nondormant sprigs were desiccated at approximately 20 and 34 C for 30 min to 10 hours. Sprigs were then planted in the field in either a vertical (45° to 90°) or a horizontal position. Measurements of percent surviving sprigs, tiller counts, and yield were made.

Generally, neither temperature treatment nor desiccation periods less than 6 hours markedly influenced the survivability of dormant sprigs. Six hours of desiccation decreased dormant sprig survivability and was more severe at 34 C; than at 20 C. Survival rate of nondormant sprigs was reduced after only 1 hour of desiccation. The highest survival percentage of nondormant sprigs exposed for 6 hours in any experiment was 11%. The production of tillers in both dormant and nondormant trials followed the same trends as stand survival. Removing roots did not affect the survival of dormant sprigs at short desiccation periods, but at 6 hours it enhanced sprig survival. Removing the roots of nondormant sprigs not exposed to desiccation resulted in reduced stands only in one experiment.

Placement of nondormant sprigs horizontally in the soil resulted in a 25% stand survival compared with 66% for the vertically placed sprigs in the check treatment.
Fertilizer Scheduling, Yield, and Nutrient Uptake of Irrigated Corn1
Authors: Rhoads F. M. , Stanley R. L.
Published: July 2010

One method of reducing nutrient loss by leaching is to schedule applications of fertilizer with small amounts applied at frequent intervals. Four fertilizer application schedules were compared for effect on grain yield and nutrient uptake of irrigated corn (Zea mays L.) on Troup loamy sand (Grossarenic Paleudult). The number of weekly applications of N, P, and K were 6, 8, 10, and 12 as four separate treatments but total amounts of nutrients were held constant.

Nitrogen and P uptake were not influenced by increasing the number of fertilizer applications. However, there was a negative correlation between K uptake and number of fertilizer applications. Yield was positively correlated with K uptake. Grain yield was 9,659 kg/ha for six fertilizer applications and 7,965 kg/ha for 12 applications of fertilizer.

Another separate experiment was conducted in 1977 and 1978 on a Ruston loamy fine sand (Typic Paleudult). Treatments consisted of populations and rates of fertilization. One treatment was considered here for the purpose of comparing yield with N, P, and K uptake between years and between soil types. Grain yield in 1978 (10,200 kg/ha) was about 80% of the 1977 yield (12,700 kg/ha) and N uptake in 1978 was about 80% of the 1977 level. Grain yield divided by total N uptake was identical for both years. The ratio of grain yield divided by nutrient uptake (GNR for N, GPR for P, and GKR for K) was highest for P in 1978 but the value for K was about the same in 1977 as in 1978.

The GNR of 62 for Ruston agreed closely with the average GNR of 59 for Troup but the GPR of 254 and GKR of 43 for Troup were lower than those for Ruston. These ratios make it possible to compare nutrient utilization efficiencies between different production management systems, years, and soil types.
Effect of Soil Fumigation on N2‐Fixation and Yield of Field Bean When Grown on Fusarium‐Infested Soils1
Authors: Bezdicek D. F. , Vigue G. T. , Burke D.
Published: July 2010

Nodulation in field beans (Phaseolus vulgaris L.) is poor in root‐rot infested soils of the Columbia Basin of central Washington. Studies were initiated to determine if nodulation and N2‐fixation rate were improved after fumigation and reduction in root rot. The effect of fumigation on nodulation and bean yield was studied in the field where N and three strains of Rhizobium phaseoli were applied to field beans grown in a Warden fine sandy loam soil (Xeroilic Camborthids) infested with root rot (Fusarium solani f. sp. phaseoli). Early nodulation with one strain but not yield, increased significantly with inoculation. Fumigation with 400 kg/ha of chloropicrin significantly increased shoot weight, root weight, and total N uptake throughout the season and decreased the incidence of root rot.

Fumigation increased seed yields by an average of 1,800 kg/ha in 1975 and 900 kg/ha in 1976. In general, N(C2H2)‐fixation rate was not significantly increased by either inoculation or fumigation. Only after adding a high rate of inoculum to the fumigated plots was the N2 (C2H2)‐fixation rate increased at one of four sampling dates. It would appear that the major increase in plant growth and seed yield following fumigation was due to a reduction in root rot rather than from an increase in nodulation or N2(C2H2)‐fixation rate. Nitrogen application of 112 kg/ha of N in 1975 and 135 kg/ha of N in 1976 did not increase yields in either fumigated or non‐fumigated soils.