bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal Dry Matter Distribution and Annual Yields of a Cool‐season Sward as Altered by Frequency and Rate of Nitrogen Application1
Authors: Burns J. C. , Gross H. D. , Woodhouse W. W. , Nelson L. A.
Published: July 2010

In a 4‐year study we evaluated several frequencies, dates, and rates of nitrogen applications for stimulating growth of a Kentucky bluegrass‐orchardgrass‐white clover sward during midsummer.

Stimulation of midseason production from the nitrogen variable was only obtained during favorable growing seasons. In such seasons the shift of nitrogen application from early March and early May to late March and late May delayed dry matter peak production by several weeks without reducing annual production.

In general, seven applications of nitrogen, to obtain an annual total of 224 kg N/ha, were no better in stimulating midsummer growth than four or three. Likewise, four applications were of no advantage over three. However, when nitrogen levels reached 894 kg/ha, the more frequent application appeared superior to three or four. Little change in midseason dry matter production was associated with changing application date from late month to early month.

Increasing nitrogen levels up to 448 kg/ha generally resulted in significant increases in dry matter production. However, when the relative yield distribution from the nitrogen treatments (1967) was compared to the check (plots receiving no nitrogen, but with adequate lime, P205 and K20) no difference was obtained.
Consumptive Use of Water by Alfalfa in Western Nebraska1
Authors: Daigger L. A. , Axthelm L. S. , Ashburn C. L.
Published: July 2010

Consumptive use of water by alfalfa grown under two phosphorus fertility levels was measured in a 3‐year study at the University of Nebraska Scotts Bluff Station, located in western Nebraska. Soil moisture to a depth of 230 cm was measured with a neutron moisture meter at the start of the growing season, after each cutting, and after the last harvest. Irrigation water was delivered to the benches through an underground pipe and measured before flood irrigation.

Alfalfa used 11.4 cm water per metric ton (4.95 in/T) of 88% dry matter hay. Alfalfa used water more efficiently in early May and June than July and August. Average water use per day was 4.1 mm (0.16 in) for the first harvest, 5.6 mm (0.22 in) for the second harvest, and 5.9 mm (0.23 in) for the third harvest. Average evapotranspiration ratios for the 3‐year period were 540 for the first cuttings, 630 for the second cuttings, and 860 for the third cuttings. The average evapotranspiration ratio for the three harvests over the 3‐year period was 680. Two levels of phosphorus applied to the soil did not alter water use nor total yields of hay.
Fate of Carbon‐14‐Labeled Cell Walls in Silage Fermentation1
Authors: Goering H. K. , Smith L. W. , Laksmanan S. , Gordon C. H.
Published: July 2010

Uniformly carbon‐14 labeled wheat plant cell walls (CW‐UL14C) were combined with ground orchardgrass hay substrate and ensiled in order to determine the contribution of cell walls to silage fermentation end‐products. Eight samples in half‐pint jars were fermented for either 49, 76, 141, 188, 237, 285, 429, or 504 hours. Carbon‐14 activity was measured in water solubles, organic acids, and carbon dioxide. Substantial activity was found in lactic and acetic acid, both of which increased at essentially the same rate initially. Eight percent of the labeled cell wall was hydrolyzed, apparently through bacterial mechanisms. Eighty percent was found in the acids and 4.5% in carbon dioxide. The usefulness of this technique for studying various ramifications of silage fermentation is demonstrated.
Residual Value of Phosphorus Fertilizer on a Calcareous Soil1
Authors: Matocha J. E. , Conrad B. E. , Reyes L. , Thomas G. W.
Published: July 2010

Yield response to applied phosphorus by grain sorghum (Sorghum bicolor L. Moench) was studied for 3 years on a Clareville clay loam, a dark, montmorillonite, calcareous soil typical of the Coastal Bend area in Texas.

Field plots to which small amounts of phosphorus had been added over a period of years were compared to those with recent, large applications. Phosphorus applied in small quantities over a period of years was as available for plant growth as recently‐applied phosphorus. Regression analyses showed that in years of drouth stress the amount of applied phosphorus required for maximum yields was larger. This suggested that lack of water severely reduced phosphorus availability in the soil.

The total amount of phosphorus applied was a better measure of availability than were extractions of phosphorus by either NH4OAc or NaHCO3. Both extractions gave a poor indication of available phosphorus present.
Effect of Seed Orientation on Emergence and Growth of Corn1
Authors: Pattern G. P. , VanDoren D. M.
Published: July 2010

Corn seed was planted in growth chambers and the field oriented proximal end down (D) and proximal end up (U). The D orientation averaged 10% greater and 3 days earlier emergence and 20% greater penetration of wax‐oil mix surface layers. Seedlings with five leaves or less averaged 15% greater root length, 300% greater vertical root penetration, and 20% greater leaf area with the D orientation. Increasing the planting depth from 2.5 to 5 cm decreased the difference in penetration of wax‐oil mix layers by 8%. Irrigation decreased the orientation induced differences in root length while good seed‐soil contact increased the differences. Seed orientation had no effect on growth with dry soil and poor seed‐soil contact. Orientation differences were greatest at an intermediate night‐day temperature regime of 15 C to 21 C. Seed orientation was not associated with any differences in mature growth when based on a common stand. Conclusions were: 1) Corn planted with D orientation will give earlier, more complete emergence with greater more rapid seedling growth and 2) Corn planted with D orientation is better able to overcome environmental deterrents to emergence and growth than the U orientation.
Water Deficit Effects on Corn. II. Grain Components1
Authors: Claassen M. M. , Shaw R. H.
Published: July 2010

Under controlled irrigation, corn plants grown in large containers were subjected to water deficits in one of nine periods during each of two growing seasons. The first experiment (1965) differed from the second (1966) by somewhat different timing of treatments and by limiting soil fertility conditions.

A significant grain yield reduction (12 to 15%) was observed after stress during the vegetative period at early ear shoot and ovule development in 1966. A 53% grain yield reduction was associated with stress at 75% silking in 1965. In the 3‐week period after silking, water deficits consistently reduced yields approximately 30% in both years. Significant reductions in kernel numbers were associated with yield reductions from stress before or during silking and pollination. Kernel weights were significantly reduced by stress during or after silking. Trends in the percentage of developed kernels in each of three ear sections indicated that the ability of kernels to compete for products of photosynthesis correlated with the comparative age of the ovule or kernel at the time of water deficit.
Limitation to Water Flux from Soils to Plants1
Authors: Lang A. R. G. , Gardner W. R.
Published: July 2010

From theoretical considerations it can be shown that there is an upper limit to the rate at which water can be taken up from the soil by plant roots. This occurs when the unsaturated permeability of the soil adjacent to the roots decreases more rapidly than the increase in the water potential gradient. Flux and water potential measurements obtained experimentally on cotton plants are consistent with this conclusion.
Promptness of Radicle Emergence as a Measure of Peanut Seed Vitality1
Authors: Mixon Aubrey C.
Published: July 2010

Peanut seed, Arachis hypogaea L., ‘Early Runner,’ from seed lots with different germination capabilities (standard germination) were evaluated for germination rate (promptness of radicle emergence), seedling emergence, and seedling vigor (dry weight). Daily radicle emergence for each of 3 days in a 25 C germinator revealed that the portion of seed that produced emerged radicles during the 1st or 2nd day resulted in quicker and greater seedling emergence and in more vigorous seedlings than did seed with radicles that emerged during the 3rd day. Plants in soil maintained at 21 ± 2 C were more vigorous when grown from seed with radicles that emerged in 1 day; but at the warmer soil temperature (27 ± 2 C), there was no difference in vigor of plants grown from seed with radicles that emerged after 1 or 2 days in the germinator. Plants from seed with radicles that emerged in 1 day emerged quicker and had greater dry weights when seed were planted 3.8 cm deep than when planted 7.6 cm deep. Differences in plant dry weight associated with planting depth were not apparent when plants were grown from seed that required 2 or 3 days for radicle emergence.
Infrared Detection of Aspergillus parasiticus Growth of Moist Sorghum Grain1
Authors: Banks J. C. , Lynd J. Q.
Published: July 2010

A method is presented for detecting Aspergillus parasiticus, Speare, growth on sterile moist sorghum grain using a dual lens infrared source and an IR scope with Type 413 IR Polaroid film recordings. Yellow to pale green “halo” patterns on inoculated whole grain were apparent with the IR scope 12 to 24 hr before visible mycelial development and aflatoxin formation. Highest B1 and G1 aflatoxin levels occurred with 120 to 144 hr incubations at 30 C in saturated humidity.
Rapid Field Measurement of Leaf Water Potential in Soybean1
Authors: Boyer J. S. , Ghorashy S. R.
Published: July 2010

Leaf water potentials of soybeans (Glycine max L. Merr.) were compared by two methods, the pressure chamber and the thermocouple psychrometer. A correlation coefficient of 0.957 was found for the two methods at leaf water potentials ranging from ‐3 to ‐25 bars. The pressure chamber method was used to measure the leaf water potential of several hundred soybean plants in different cultural studies in 1969 at Urbana, Illinois and found to be a rapid, efficient method.
Influence of Aluminum on Plant Growth and Tuber Yield of Potatoes1
Authors: Lee C. R.
Published: July 2010

Potatoes (Solanum tuberosum L.) var. ‘Netted Gem’, and ‘Sebago’ were grown in greenhouse sand cultures. Plants were watered daily with nutrient solutions containing 0, 5, 10, or 20 ppm of AI. Aluminum depressed plant growth and number and yield of tubers for both varieties. Yield of knobby tubers was lower with added AI. The addition of 20 ppm of AI to the growth medium decreased the yield of small tubers, increased the yield of larger tubers and increased the specific gravity of the tubers for both varieties.
Response of Corn to Small Amounts of Fertilizer Placed with the Seed: III. Relation to P and K Placement and Tillage1
Authors: Bates T. E.
Published: July 2010

Fertilizer was banded with the seed of corn (Zea mays L.) in a number of field trials at rates supplying 3.1, 5.4, and 2.5 g N, P, and K per meter of row, respectively. Fertilizer with the seed was applied in combination with separate and larger applications of N, P, and K at various placements and with different amounts of preseeding tillage.

Nitrogen placement did not appear to be critical in these trials.

When no fertilizer was applied with the seed, grain field was slightly greater where P was side banded than where it was disked or plowed down. When accompanied by fertilizer with the seed, P was as effective where it was plowed down as it was where it was side banded; but P disked in was not. Lower yields were obtained with disked K than with plowed down or side banded K. Fertilizer with the seed reduced the difference between K placements at early growth stages in one trial, but this interaction was not apparent in other trials or in grain yield.

Fertilizer with the seed reduced the yield response to preplanting tillage in one trial out of five.
Effect of Light Intensity, Temperature, Nitrogen, and Stage of Growth on Nitrate Accumulation and Dry Matter Production of a Sorghum‐Sudangrass Hybrid1
Authors: George J. R. , Rhykerd C. L. , Noller C. H.
Published: July 2010

Two growth chamber experiments were conducted to study short‐ and long‐term effects of environment and nitrogen on nitrate accumulation in the sorghum‐sudangrass ‘Sudax SX‐11.’ Plants receiving high rates of nitrogen and grown under 43 klux light intensity at 22.5 C increased nearly twofold in nitrate content overnight when moved to 4.3 klux light intensity. Nitrate accumulation was progressively greater at high temperatures, and continued to increase during the next 7 days at high levels of nitrogen fertilization. In a second experiment, there was a decreasing trend in nitrate accumulation for plants grown under environmental regimes of 4.3 klux at 22.5 C, 4.3 klux at 30 C and 43 klux at 22.5 C. An extended period of cool temperature and low light intensity decreased dry matter production and increased nitrate accumulation. Although higher levels of nitrate were found to accumulate with increasing rates of nitrogen fertilization, the level of plant nitrate was observed to be lower at later stages of growth.
Emergence of Kenaf Seedlings as Affected by Seed Fungicides1
Authors: White G. A. , Adamson W. C. , Whiteley E. L. , Massey J. H.
Published: July 2010

Effects of four chemical seed treatments on seedling emergence of three seed lots of kenaf (Hibiscus cannabinus L.) were studied at several locations in 1969‐70. No beneficial effects of chemical seed treatments were found from a late planting at Experiment, Ga. At Savannah, Ga., in 1969, significantly more seedlings emerged from an early April planting of seed treated with tetrachloroisophthalonitrile (Daconil 2787)3 ‐ sodium p‐(dimethylamino)benzenediazosulfonate (Dexon)3 + 1,4‐dichloro‐ 2,5‐dimethoxybenzene (chloroneb) and bis(dimethylthiocarbamoyl) disulfide (thiram) than from the check. For combined 1969‐70 data for ‘Everglades 71’, only N‐(ethylmercury)‐p‐toluenesulfonanilide (Ceresan M)3 + chloroneb was superior to the check. At Glenn Dale, Md., chemical seed treatment was beneficial in both 1969 plantings and in an early 1970 planting. In these tests Ceresan M + chloroneb was inferior to the other chemical treatments. Equally good results were obtained from thiram, thiram + chloroneb, and Daconil 2787‐Dexon + chloroneb. Thiram gave the best results in a 1969 test at College Station, Texas. Seedling emergence from ‘Everglades 41b’ seeds, that had an initial laboratory germination of 83%, was enhanced by chemical treatment. In field tests at Savannah and Glenn Dale, only 65% emergence was obtained for the untreated check compared to an average of 78% for the four chemical treatments. In general, differences among chemical treatments were small and all of them except Ceresan M could be used pending registration.
Levels and Sources of Potassium for Alfalfa as Influenced by Temperature1
Authors: Smith Dale
Published: July 2010

Studies were conducted with KCl and K2SO4 as K sources (0, 336, and 672 kg/ha of added K) for alfalfa (Medicago sativa L.) grown to first flower in growth chambers at 21/15 C day/night temperatures. Growth and mineral composition of alfalfa at first flower in three temperature regimes (27/21, 21/15, and 15/10 C) also were studied in low‐K soil with 0, 168, 336, and 672 kg/ha of K added as K2SO4.

KCl applied at high rates (672 kg/ha of K) to soil containing 205 kg/ha of exchangeable K caused damage to alfalfa plants grown in pots, presumably from the Cl ion. No injury was noted with K2O4.

K2SO4 applied (168, 336, and 672 kg/ha of K) to soil containing 120 kg/ha of exchangeable K increased herbage, root, and total plant yields, plant heights, and shoot numbers at the first flower growth stage. Largest increases occurred with the first increment of K and when grown at cool temperatures. Percentage of K in the herbage was highest at all rates of applied K in the warmest temperature regime (27/21 C day/night temperatures) and lowest in the coldest regime (15/10 C). Percentages of K in the herbage grown at 15/10 C were all below K‐sufficiency (2.20%) at all rates of K. Higher levels of exchangeable K are needed in the soil under cool than under warm temperatures in order for the plant to obtain sufficient K for maximum growth and production.
Modification of a 360‐Degree Antenna Rotor for Continuous Stepped Rotation1
Authors: Perrier E. R. , Rogers J. S. , Stahl G. R.
Published: July 2010

An antenna rotor was modified to operate continuously stepwise automatically. The rotor was used to support a vertical profile of micrometeorological apparatus and swept a large surface area above crop rows and bare soil surfaces. The necessary modifications are easy to perform by modifying the control unit of the AC shaded‐pole induction motor.
Soil Tests as a Means of Predicting Response of Rape to Added N, P, and K1
Authors: Soper R. J.
Published: July 2010

Soil tests were evaluated as a means of predicting response of rape to added N, P, and K in 23 field experiments on non‐fallowed soils from 1961 to 1969. Nitrate‐N content to a depth of 61 cm, NaHCO3‐extractable P, and NH4OAc‐extractable K of soils were found to be useful in predicting yield response of rape to added N, P, and K. Rape responded to added N when NO3‐N in the soil to a depth of 61 cm was >100 kg/ha, responded to added P when soils had NaHCO3‐extractable P <10 ppm, and responded well to added K when soils had 35 or less ppm of NH4OAc‐extractable K.
Variation of Reserve‐Starch‐Granule Areas and Diameters in Andropogon gerardi Rhizomes1
Authors: McKendrick Jay D. , Anderson Loran C.
Published: July 2010

Warm‐season perennial grasses store reserve carbohydrates as starch granules, which are suspected deterrents to cold hardiness. In contrast, cool‐season perennial grasses store reserves as fructosans. Thus, the sizes and amounts of reserve starch granules in over‐ wintering rhizomes may impair cold hardening, thereby restricting the northern limits of species and varieties of warm‐season perennial grasses. That theory's validity was investigated in big bluestem (Andropogon gerardi Vitman), a native warm‐season perennial occurring over a wide range of eastern Great Plains' habitats. Areas and diameters of reserve starch granules in mature rhizomes were measured on projected color transparencies of mounted and stained tissues collected at seven habitats representing a gradation in winter severity. Average starch granule areas ranged from 2 to 23% and were significantly greater in tissues from habitats with severe winters and shorter growing seasons. Starch granule diameters were similar among locations and among sampling dates within locations.
Influence of Cultural Practice and Field Environment on Consistency of Corn Yields in Northern Areas1
Authors: Andrew R. H. , Peek J. W.
Published: July 2010

Four adapted corn hybrids (Zea mays L.) were grown in 76 cm and conventional rows at populations per hectare of 40, 50, 60, and 70,000 in 12 environments as provided by planting date and irrigation over a four−year period at two locations in Wisconsin. Analyses of variance were computed for yield within environments and at each hybrid‐cultural combination across environments. Attention was given to determining and interpreting optimum hybrid−cultural combinations within environments and consistency of performance across environments.

Average overall grain yield was 6,394 kg/ha; and maximum yield was 11,441 kg/ha. Yield in conventional rows averaged 93.6% of yield in 76−cm rows, with greater differences for the dry year, late plantings, high populations, and late hybrid. In the favorable environments, first planted and irrigated, yields increased with population up to 60,000 while in the unfavorable environments, late planted and non−irrigated, yields were highest at the low population. Differences due to population were more pronounced in the unfavorable environments. Variance across environments averaged lowest for the 40,000 population and highest for the 70,000 population and for the late hybrid. Hybrid differences were greater for the first planting and in non−irrigated plots. Hybrid and population effects were small under irrigation. Coefficients of variability averaged highest for the unfavorable and lowest for the favorable environments.
Digestibility of Mechanical Mixtures of Early and Late Cut Tall Fescue
Authors: Rai S. D. , Hinds F. C. , Isaacson H. R. , McKibben G. E.
Published: July 2010

In vitro and in vivo dry matter digestibilities for four qualities of tall fescue (Festuca arundinacea) hay were determined. The variations in quality we obtained by harvesting low and high quality material from the same field and the intermediate qualities were obtained by making mechanical blends (33% high quality and 66% high quality) of the high and low quality materials. The in vitro procedure used was a modification of the Tilley and Terry procedure.

Dry matter digestibility and ad libitum intake of the above feeds were determined with lambs using a 4 ✕ 4 Latin square. Increasing the proportion of high quality forage in the mixture gave a linear increase in in vivo digestibility, but there was no significant difference between the 66% high quality and 100% high quality samples. The pattern of increasing digestibility was similar in vitro and in vivo.

The use of mechanical blends of extremely different qualities of samples of the same forage species appears to be a potentially valuable approach to elucidating factors influencing forage quality.
Nitrogen and Phosphorus Responses of Sorghum and Corn in Uganda1
Authors: Jowett David
Published: July 2010

Seven fertilizer trials testing rates and combinations of N and P were conducted on corn (Zea mays L.), a grain sorghum variety [Sorghum bicolor (L) Muench.] and a sorghum hybrid in Uganda in 1964. In general, corn outyielded sorghum, and showed a better response to applied fertilizer, but the interpretation of the results was complicated by a puzzling significant negative NP interaction for sorghum. The results support the hypothesis that sorghum is better adapted to low soil fertility than is corn in Uganda, but such a conclusion cannot be established on the basis of such slender evidence as is here made available.
Response of Grain Sorghum to Iron Sources Applied Alone or with Fertilizers1
Authors: Mortvedt J. J. , Giordano P. M.
Published: July 2010

Soil applications of inorganic Fe sources are generally not effective for crops unless rather high rates are applied. Since previous results had indicated that these sources may be effective if applied at lower rates with fluid polyphosphate fertilizers, several greenhouse pot tests were conducted.

Dry matter production and Fe uptake by grain sorghum (Sorghum bicolor) were higher with FeEDDHA than with FeSO4 or Fe2(SO4)3 applied to Epping sil (pH 7.5), a calcareous soil low in available Fe. There was very little crop response to either inorganic Fe source applied alone to the soil at rates up to 24 ppm Fe. However, both sources were somewhat effective when applied with fluid polyphosphate fertilizers at the same rates. Seed and foliar spray applications were not as effective as soil application, probably because the rate of Fe was limited by the application method. Without applied Zn, crop response to FeEDDHA was limited. However, Zn uptake by sorghum decreased while forage yields increased with FeEDDHA application rate, even though ZnSO4 was also applied to the soil. Evidence for a marked Fe‐Zn interaction in sorghum was shown on this soil. Application of ZnSO4 to the no‐Fe check treatment reduced growth and Fe uptake, while high Fe applications reduced Zn uptake in the presence or absence of applied Zn.
A Planter Designed for Rapid and Uniform Sowing in Flats
Authors: Miner Gordon S.
Published: July 2010

A planter was designed and built to facilitate the sowing of seed in soil‐filled wooden flats. All seed is placed at a given depth resulting in uniform emergence of plants. The planter also provides a rapid method of sowing on flats.
Yields and Protein Contents of Crops in Various Rotations1
Authors: Hobbs J. A.
Published: July 2010

In 1956 a study was initiated at Manhattan, Kansas, to measure effects on crop yield and protein content of five crop rotations: continuous wheat; continuous grain sorghum, sorghum, wheat, wheat; alfalfa, (2 years), sorghum, wheat, wheat; and bromegrass (2 years), sorghum, wheat, wheat. The study had a split plot, randomized block design with four replications. Three levels of nitrogen fertilizer were superimposed over the rotation variables.

Cereal crop yields were not improved by including other cereals or perennial crops in a rotation on a Geary silty clay loam, upland soil. From 1959 through 1967 average wheat yields were highest in the continuous wheat system; sorghum yields were best in the sorghum, wheat, wheat rotation, and in the continuous sorghum system. More often than not sorghum yields were reduced following the perennial crops, due no doubt to moisture deficiency.

Nitrogen fertilizer, which increased wheat yields in some years and decreased them in others, had little effect on the 9‐year average wheat yields. Nitrogen fertilizer generally increased sorghum yields.

Protein content of cereal grain was highest in the alfalfa rotation and was increased by applying nitrogen fertilizer.
Phosphorus Placement for the Establishment of Alfalfa and Bromegrass1
Authors: Sheard R. W. , Bradshaw G. J. , Massey D. Lawrence
Published: July 2010

Efficient production of forage species is greatly hindered by inadequate stands. The results from a greenhouse and two field experiments using 32P‐labeled, monocalcium phosphate showed increased P uptake from fertilizer placed five cm directly below surface sown seed of alfalfa (Medicago sativa L.) or bromegrass (Bromus insrmis L.). Dispersing the P throughout the soil volume, localizing the P on the soil surface, or moving the band laterally from a position directly below the seed, all decreased fertilizer P uptake, and as a result reduced the weight of individual seedlings of both species from that obtained where the fertilizer P was placed directly below the seed.

Fifteen days after seeding, alfalfa and bromegrass seedlings emerging directly over the fertilizer band obtained 50 to 56% of their P content from the fertilizer. Only 2.5 to 6.5% of total P was obtained from the fertilizer where the band was located 3 cm laterally, and none from bands located at a 6 or 9 cm lateral displacement. The root system of the two species did not reach the 9 cm band until 29 days after planting. Fifty days after planting, 10 to 14% of the P was derived from the fertilizer band in plants grown with a 9‐cm lateral displacement of the fertilizer band, in contrast to half the P absorbed from the fertilizer by plants grown directly over the fertilizer band.

The increased utilization of fertilizer P by both grass and legume species at a very early stage in growth when the fertilizer is banded directly below the seed will result in more vigorous seedlings, and greatly reduce the hazards of forage establishment.
Effect of N Fertilization and Simazine on Yield, Protein, Amino‐acid Content, and Carotenoid Pigments of Coastal Bermudagrass1
Authors: Monson Warren G. , Burton Glenn W. , Wilkinson W. S. , Dumford S. W.
Published: July 2010

Reports of increased protein levels in several plant species with simazine treatments prompted this study of the response of coastal bermudagrass (Cynodon dactylon L. Pers.) to simazine. Simazine was applied at rates ranging from 0 to 4.5 kg/ha on an old sod of coastal bermudagrass. Additional variables were N fertilization (56 to 672 kg/ha) and cutting frequency (3 and 6 weeks). Nitrogen fertilization and cutting frequency significantly affected yields of dry matter and protein. Simazine applications had no effect on dry‐matter yield, protein yield, or protein percentage. Carotene and xanthophyll contents of the grass increased with an increase in N fertilization from 336 to 672 kg/ha. Carotene content of the grass tended to increase due to simazine treatment with 360 kg/ha N and to decrease with 672 kg/ha. Samples were analyzed for 15 amino acids, and differences between the amino‐acid profile of the protein from check and simazine‐treated samples suggested that simazine may alter amino acid composition of protein.
Profile Modification and Root Yield, Distribution, and Activity1
Authors: Eck Harold V. , Davis Ronald G.
Published: July 2010

Deep plowing or other profile medication of a soil may alter root yield and distribution. Root systems of plants grown on soil rotary tilled 20 cm deep; plowed 90 cm deep; and plowed 90 cm deep with 22,400 kg/ha of Na2CO3 were sampled to (i) determine effects of treatments on yield and distribution of roots, and (ii) examine relationships between root yields and root activity as indicated by top‐root ratios and Sr85 uptake.

Deep plowing tended to decrease root yields of sudangrass (Sorghum sudanense), sugarbeets, (Beta vulgaris), and soybeans (Glycine max) but had little effect on those of cabbage (Brassica oleracea var. ‘capitata’). Root yields decreased with depth on soil rototilled to 20 cm or moldboard plowed to 90 cm, but roots tended to be evenly distributed throughout the 90 cm profile when 22,400 kg/ha of Na2CO3 was applied at the 90‐cm plow depth.

Root activity, as measured by top‐root ratios, was enhanced by profile modification. Top‐root ratios are shown to be better indicators of root activity than top or root yields alone.

Sr85 uptake data indicated that roots in the 70‐ to 90‐cm zone were as active as those in the O‐ to 20‐cm zone. Na2CO3 tended to increase root weights in its zone of application but reduced radiostrontium uptake about eightfold compared with uptake from similarly placed radiostrontium without Na2CO3, indicating a Na2CO3‐induced decrease in root activity.
Temperature Influence on Herbicide Injury to Navy Beans1
Authors: Penner Donald , Graves Dennis
Published: July 2010

Injury to navy bean (Phaseolus vulgaris L.) by 2‐chloro‐2',6'‐diethyl‐N‐(methoxymethyl) acetanilide (alachlor) was observed at 20 and 25 C but not at 30 C. This injury was observed in the ‘Sanilac,’ ‘Seafarer,’ and ‘Gratiot’ varieties but not in the ‘Michelite’ variety. The herbicides S‐ethyl dipropylthiocarbamate (EPTC) and α,α,α‐trifluoro‐2,6‐dinitro‐N,N‐dipropyl‐p‐toluidine (trifluralin) did not injure the navy beans at 20, 25, or 30 C under the controlled environment of the experiment at rates up to twice the 3.37 and 0.85 kg/ha rates, respectively, used in the field. Navy beans were injured at all temperatures studied, 20 C, 25 C, and 30 C, by 3‐(3,4‐dichlorophenyl)‐ l‐methoxy‐l‐methylurea (linuron) at three‐fourths the rate used for weed control in soybeans [Glycine max (L.) Merr.].
Dieldrin and Heptachlor Residues in Soybeans1
Authors: Turner B. C. , Taylor A. W. , Edwards W. M.
Published: July 2010

Where soybeans [Glycine max (L.) Merr.] are grown on land previously planted to maize (Zea mays L,.), the soybean crop may be contaminated with residues of organochlorine insecticides applied to the soil for control of soil‐borne predators attacking maize. Experimental findings on the decrease of contamination with time are meagre. In 1970, soybeans were grown on experimental fields that had received 5 kg/h of dieldrin, mixed to the 7.5‐cm depth in 1970, 69, 68, 67, and 66. Residues in the soybeans declined rapidly over the first 2 years after application, but showed little further change in the 3rd through the 5th year. At harvest, beans from the lower half of the plant contained 0.31 ppm from the 1970, 0.132 ppm from the 1969, and 0.038 ppm from the 1968 applications. Beans from the upper half contained ½ to ¼ of these amounts. Heptachlor residues, principally heptachlor epoxide, from a parallel treatment in 1969 were less than the dieldrin. The data confirm that soybeans should not be planted for 2 years after soil has been treated with dieldrin.
Effects of Low Levels of Atrazine on Some Mineral Constituents and Forms of Nitrogen in Zea mays L.1
Authors: Hiranpradit H. , Foy C. L. , Shear G. M.
Published: July 2010

Sublethal concentrations of s‐triazine herbicides are known to increase the protein in plants. Conceivably, the effect may be related to increased nutrient accumulation or to stimulation of enzymes involved in nitrate reduction and/or carbohydrate utilization for amino acid and protein synthesis. A study was undertaken to determine the effects of subtoxic levels of atrazine (2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine) on the mineral constituents, forms of N, and growth of 28‐day‐old corn (Zea mays L. ‘Cribfiller’) plants

Corn was grown in soil containing various levels of atrazine under greenhouse conditions and analyzed after 28 days. Atrazine at 1.5 ppm (7.0 µM) concentration did not significantly affect plant dry weight, but significantly increased percentages of N and K compared with untreated controls. Total amounts of N, P, K, and Ca per plant were significantly increased over the untreated controls by 18.9, 14.9, 16.4, and 13.8%, respectively. The treated plants contained significantly more nitrate‐N, protein‐N + nucleic acid‐N, and chlorophyll‐N + lipid‐N than the untreated controls. The increases were 14.2, 39.0, and 31.2%, respectively. Total amounts of acid soluble‐N and ammonium‐N were not significantly increased. Overall, there was an increase in amino acids that form the constituents common to nearly all protein, molecules.
Effects of Low Levels of Bromacil on Some Mineral Constituents and Forms of Nitrogen in Glycine max (L.) Merrill1
Authors: Hiranpradit H. , Foy C. L. , Shear G. M.
Published: July 2010

Certain s‐triazine herbicides are known to increase the protein in plants perhaps by enhancing nutrient accumulation and/or affecting enzymatic conversion in N and carbohydrate metabolism. Conceivably, other proven inhibitors of photosynthesis could have similar effects. The present study was conducted to determine the effects of subtoxic levels of bromacil (5‐bromo.3‐sec‐butyl‐6‐methyluracil) on the mineral constituents, forms of N, and growth of 28‐day‐old soybean [Glycine max (L.) Merrill. ‘Lee’] plants.

Soybeans were grown in soil containing various levels of bromacil under greenhouse conditions and analyzed after 28 days. Bromacil at 0.0225 ppm (0.086 µM) concentration did not significantly affect plant dry weight but significantly increased both percentages and total amounts of N and P in plant shoots compared with untreated controls. The increases in total amounts of N and P per plant were up to 15.0 and 15.6% more than the untreated controls. The treated plants took up about 18% more nitrate‐N than the untreated controls, which resulted in significantly higher accumulation of protein‐N + nudeic acid‐N in the plants. Total amounts per plant of acid soluble‐N and ammonium‐N also tended to be increased. Overall, there was also an increase in amino acids that form the constituents common to nearly all protein molecules.
Effectiveness of Resistance in Maize to Maize Dwarf Mosaic1
Authors: Scott Gene E. , Nelson Lloyd R.
Published: July 2010

Our objectives were to determine the effect of maize dwarf mosaic (MDM) on the performance of corn (Zea mays L.) hybrids as well as to determine the effectiveness of resistance in preventing yield losses. Diallel crosses among corn inbred lines known to be resistant or susceptible to maize dwarf mosaic were grown in field experiments. Paired‐row plots of each hybrid were grown and one row was inoculated with the maize dwarf mosaic virus (MDMV). Comparisons were made between the inoculated and noninoculated rows for percentage of diseased plants, plant height, yield (g/pl), ears/100 plants, weight/500 kernels, and days to midsilk. Crosses between inbreds known to be resistant were not materially affected by MDM and, thus, were effective in preventing yield losses by this disease. This disease, however, reduced grain yield on both the resistant ✕ susceptible and susceptible × susceptible crosses. Plant height and number of ears per 100 plants were also reduced by MDM in these same crosses. Plots of susceptible hybrids that were inoculated required more time to reach the midsilk stage of growth than noninoculated plots.
Agronomic Response of Three Height Classes of Spring Wheat, Triticum aestivum L., Compared at Different Yield Levels1
Authors: McNeal F. H. , Berg M. A. , Stewart V. R. , Baldridge D. E.
Published: July 2010

‘Centana’ (Cnt) plus short, medium, and tall selections of Norm 10/Brevor, 14//6*Centana were grown in yield nurseries at 22 Montana locations in 1969 and 17 locations in 1970. The study was designed to determine the magnitude of the genotype by environment interactions of the three height classes when grown under Montana conditions. Such information is needed to help define the limitations, if any, of semidwarf spring wheats. Agronomic data from each location are reported within one of six yield levels, each level separated by 673 kg/ha (10 bu/acre), with the location average yield determining the yield level assigned.

Medium Cnt had the highest grain yield at all yield levels, except at one location which yielded less than 1352 kg/ha (20 bu/acre). Short Cnt was consistently lowest of the four entries in grain yield and test weight. Short Cnt increased only 29.3% in plant height from the second to sixth yield level, whereas other varieties increased more than 48%. The grain:straw ratio was highest for short Cnt and lowest for Centana and tall Cnt.

The data suggest that breeding efforts for Montana spring wheat should emphasize the development of single gene dwarfs (semidwarfs), and that 2‐gene dwarfs (short selections) generally should be avoided.
Fixation and Excretion of Nitrogen by Tropical Legumes1
Authors: Agboola Akinola A. , Fayemi Adeboyejo A. A.
Published: July 2010

Since earlier investigations revealed that interplanted legumes competed with a late crop of corn (Zea mays L.) and suggested that legumes were incapable of benefiting associated nonlegumes over the same growing period, relatively short‐season legumes, calopo (Calopogonium mucunoides), cowpea (Vigna sinensis), and greengram (Phaseolus aureus), were interplanted with corn in the early cropping season to measure their effects on both the early planted and the late‐planted corn crops.

Two days after harvesting the intercrops of corn and legumes, soil samples from the 0‐ to 15‐ and 15‐ to 30‐cm depths were collected from the unfertilized plots of control (no legume), cowpea, greengram, and calopo in order to determine in the greenhouse the soil N status. Two other greenhouse experiments were conducted to check the N‐fixing and N‐excreting ability of the legumes.

The investigations showed that calopo, cowpea, and greengram fixed N when planted alone and when interplanted with corn. Cowpea and calopo interplanted with corn did not benefit the early corn crop, but as green manure they were an important source of N for the corn in the late‐cropping season. On the other hand, greengram interplanted with corn in the early season increased yield of the early corn crop but contributed very little to the yield of the late corn crop.

The data also revealed that tropical legumes are capable of fixing large quantities of N under improved conditions. Calopo, cowpea, and greengram fixed equivalents of 450, 354, and 324 kg/ha, respectively, when inoculated and grown in a complete nutrient culture (except for N) as compared to 370, 157, and 63 kg/ha, respectively, when not inoculated and grown in unfertilized soil.
Influence of Soil Temperature on the Geotropic Response of Corn Roots (Zea mays L.)1
Authors: Mosher P. N. , Miller M. H.
Published: July 2010

Experiments were conducted in controlled temperature cabinets to determine the factor that caused corn (Zea may L.) radicles to grow nearly straight down from the seed in a greenhouse experiment conducted during the summer, and horizontally in a second experiment conducted during the winter.

The possibility of horizontal growth caused by atrazine residues in the soil of the second experiment was eliminated when this type of growth was observed in vermiculite as well. Nearly vertical growth was observed when radiant energy from a heat lamp was directed onto the soil surface. The possibility that the roots followed a temperature gradient was eliminated by demonstrating vertical growth toward as well as away from the radiant energy. The soil temperature at the seed was found to be the primary factor involved. The angle of radicle growth varied from 30° from the horizontal at 18 C to 61° from the horizontal at 36 C.

The influence of soil temperature on the direction of radicle growth explains many observations on root growth from the literature. It appears that the direction of growth of the radicle as well as that of the seminal and nodal roots is controlled by soil temperature.
Relationship of pH to Ion Uptake Imbalance by Varieties of Wheat (Triticum vulgare)1
Authors: Dodge C. S. , Hiatt A. J.
Published: July 2010

Varietal differences in plant‐induced pH changes have been considered a possible factor in Al tolerance. The objective of this study was to determine the magnitude of plant‐induced pH changes by wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) and to determine the cause of observed varietal differences. Varieties of wheat or barley differed considerably in their effect on the pH Level of complete nutrient solutions. Ion uptake and H+ transfer between plants of three varieties of wheat and KNO3‐Ca(NO3)2 solutions were measured to determine the reason for varietal differences in plant‐induced pH shifts. Changes in nutrient solution pH were attributable to differences in anion and cation absorption. Consequently, varietal differences in effect on solution pH levels were accounted for by varietal differences in anionminus‐cation uptake (A‐C) values.

Nutrient solutions from which anions had been absorbed in excess of cations were highly buffered. This buffering capacity was lost when the solutions were acidified and aerated, suggesting that HCO‐3 exchanged for the excess anions.

Plant‐induced changes in nutrient solution pH varied with the form of N in the solution. When NO3‐ was the only form of N present, pH levels consistently increased from the initial level. However, solution pH decreased when NH4+ was present in quantities as low as 0.5% of the total N.
Apparent Induction of Nitrate Uptake in Nitrate‐depleted Plants1
Authors: Jackson W. A. , Volk R. J. , Tucker T. C.
Published: July 2010

Previous investigations revealed that nitrogen‐depleted wheat absorbed nitrate slowly on first exposure to nitrate solutions. Subsequently, however, the rate of nitrate uptake increased. The present studies were initiated to more thoroughly characterize this response in wheat, and to determine if other species responded similarly. Nitrate uptake of various species was determined from changes in the amount of nitrate in the external solution. Both chemical and isotopic procedures were employed. With nitrogen‐depleted wheat, the characteristic two‐phase pattern was observed even when nitrate uptake was severely restricted by presence of ammonium. Chloride uptake differed from nitrate uptake in two ways; the initial slow phase was not observed and the tissue reached chloride flux equilibrium at about six hours. Corn seedlings previously grown with ammonium showed the two phase pattern of nitrate uptake whereas linear rates were observed when they were previously grown with nitrate. After being deprived of nitrate, cotton and tobacco both exhibited the two‐phase pattern of nitrate uptake.
Influence of Nitrogen Fertilizer on Stands, Yields of Herbage and Protein, and Nitrogenous Fractions of Field‐grown Alfalfa1
Authors: Lee Chin‐tian , Smith Dale
Published: July 2010

Studies of fertilizing alfalfa (Medicago sativa L.) with N were initiated because of the possibility of increasing protein yields since there is current interest in the leaves or herbage as a sourc of a concentrated protein for human and animal consumption. Two N fertilization trials were conducted at Arlington, Wis., on established stands.

The first experiment was conducted during 1968 with a 2‐year‐old stand of ‘Vernal’ alfalfa. Six N treatments (0, 56, 112, 224, 448, and 896 kg/ha of N as NH4NO3) were initiated in April and repeated in separate areas after the first harvest and after the second harvest. Each harvest was made at first flower. N had no significant effect on stands, herbage yields, or herbage total nonstructural carbohydrate percentages. N significantly increased protein yields only in the third harvest. Percentages of total‐, non‐protein‐, nitrate‐, free α‐amino‐, asparagine‐, and glutamine‐N in leaflets, stems, and total herbage were increased with each increase in N rate, but percentage of ammonium N was not affected. Protein percentages in leaflets were not affected by N rates, but they increased slightly in both the stems and total herbage as N rate increased.

A second experiment was conducted during 1969 and 1970, in the same field of alfalfa as in 1968, when all N treatments had 336 kg/ha of N applied annually in various ways. Treatments were (1) no N; (2) all N applied in the spring, (3) after the first harvest, or (4) after the second harvest; (5) half the N applied in the spring and half after the first harvest, or (6) after the first and second harvests. All harvests were made at first flower. Stands were not affected by the treatments. N treatments significantly increased the total seasonal herbage and protein yields in both years, with a few exceptions in 1969 for protein. However, there was no significant difference among the N treatments that significantly increased yields. The average yield increase over the control amounted to only 6.1% for herbage and 12.2% for protein in 1969, and 16.0% for both herbage and protein in 1970.
Experimental Curves and Rates of Change from Piecewise Parabolic Fits1
Authors: DuChateau P. C. , Nofziger D. L. , Ahuja L. R. , Swartzendruber D.
Published: July 2010

The determination of experimental curves and rates of change for nonlinear data is approached and solved without assuming an artificially restrictive mathematical form for the complete range of the data. This relatively form‐free result is achieved by least‐squares computer fitting of parabolic segments to short subranges of the experimental data. Two ways of doing this, referred to as the sliding‐parabola and the parabolic‐splines methods, are developed. These are tested on both smooth and scattered data generated basically from the function y = x1/2, without and with random error, respectively. for smooth data the sliding‐parabola method is slightly better than the parabolic splines, but in general both are subject to only very small errors, and are also in good agreement with a previously presented graphical prism method. For scattered data wherein the inherent errors of function and slope evaluation are much increased, the parabolic‐splines method is distinctly superior to the sliding parabola method. Both methods require only relatively short computing times, on the order of 1 sec for 40 data points, and are of utility for determining nonconstant experimental rates of change and for least‐squares curve fitting without specification of a complete‐range mathematical curve.