bluuebunny/crossref_metadata_2025 huggingface dataset:
Phenolic Acids in Oats, Wheat, Sorghum, and Corn Residues and Their Phytotoxicity1
Authors: Guenzi W. D. , McCalla T. M.
Published: July 2010

Five phenolic acids, ferulic, p‐coumaric, syringic, vanillic, and p‐hydroxybenzoic, were quantitatively estimated in corn, wheat, sorghum, and oats residues, p‐Coumaric acid was present in greater concentration than the other acids. Acid and base hydrolysis were used to free the acids from the bound form. Higher concentrations of phenolic acids were found in the alkaline hydrolysate, indicating that the acids are probably bound by an ester‐type linkage. Concentrations of the cinnamic acid derivatives in the acid hydrolysate are probably low due to the breakdown of the free phenolic acids after acid hydrolysis. It appears that under ideal decomposition conditions, p‐coumaric acid might be released in sufficient quantity in localized areas of the soil to affect plant growth.
Plant Ethanol Content as an Index of the Soil‐Oxygen Status1
Authors: Aubertin G. M. , Rickman R. W. , Letey J.
Published: July 2010

The feasibility of using the plant ethanol content as a measure of the soil‐oxygen status was investigated. No satisfactory correlation between the oxygen status of the growth media and the plant ethanol content was found. The plant ethanol content was related to the plant's morphological age and development as well as the oxygen treatments imposed. The results of these experiments appear to rule out this method as a diagnostic method of characterizing the oxygen status of the growth medium.

The findings have considerable implication when one considers the use of the plant ethanol content as a measure of the soil oxygen status.

First, plants grown under continuous low root zone oxygen conditions for an extended length of time do not exhibit the high ethanol content which plants grown under an adequate oxygen supply in the root zone do after suddenly being subjected to a low root zone oxygen supply for short periods of time. This means that this method would not be suitable for detecting prolonged periods of unfavorable oxygen conditions, but may, under certain instances, be useful in detecting periods of short adverse oxygen conditions.

Second, the dependency of the plant ethanol content on the plant's morphological age overshadows the effects of the oxygen stresses imposed on the plant grown continuously under conditions of adverse oxygen supply, thus making the selection of individual plants selected for measurements extremely critical.

Third, the large variability in the values of ethanol content obtained from individual plants apparently at the same morphological age, when grown continuously under a given set of oxygen stresses, makes the use of this method for predicting the soil oxygen status from measurements of the plant ethanol content very doubtful.
Sample Changer for Thermocouple Psychrometers: Construction and Some Applications1
Authors: Campbell G. S. , Zollinger W. D. , Taylor S. A.
Published: July 2010

A sample chamber capable of holding six samples has been designed and used with Peltier and wet‐loop vapor pressure psychrometers for measuring the water potential of both plant tissues and soil. Two modifications of the basic design are found useful, one for soil, and another for plant leaf tissues. A punch designed to take samples of leaf tissue and position them directly into the measuring chamber also was constructed. Gradients in plant water potential along with single leaves were measured. Data are presented for such gradients in corn leaves and in horse chestnut leaves. Potentials were higher near the stem or stalk and decreased as the tip or edge of the leaf was approached.
Compatibility of Rhizobium japonicum and Sodium Molybdate when Combined in a Peat Carrier Medium1
Authors: Burton J. C. , Curley R. L.
Published: July 2010

Experiments were conducted to study the effect of sodium molybdate on soybean rhizobia when combined in a peat carrier medium in proportions which would ordinarily be used on soybean seeds. Laboratory tests showed a 99% kill of rhizobia within 4 days and no subsequent recovery. Survival of soybean rhizobia was not improved by incorporating the molybdenum into peat or charcoal premixes before blending with the rhizobia‐containing inoculant.

Field tests with ‘Chippewa’ soybeans planted in a soil virgin to soybeans confirmed that the inoculant‐molybdenum combinations contained too few rhizobia to bring about effective nodulation even when used as early as 3 weeks following preparation. Poor nodulation was reflected in low yields. When sodium molybdate was mixed with the inoculant immediately before application to the seed at planting time, excellent nodulation and increased yields were obtained.
Interactions of Soil Moisture, Nitrogen, and Clipping Frequency on Yield and Nitrogen Content of Coastal Bermudagrass1
Authors: Doss B. D. , Ashley D. A. , Bennett O. L. , Patterson R. M.
Published: July 2010

Studies were conducted at Thorsby, Alabama, during 1961 and 1962 to determine the interactions of soil moisture regime, rate of N, and clipping frequency on yield and N content of Coastal bermudagrass (Cynodon dactylon (L.) Pers.).

The major and most consistent interaction on yield was between moisture regime and N rate. Yield response to irrigation was obtained when N rates were 400 pounds or higher. The largest yield response to N rates was from the first increment at the higher levels of moisture. The interactions of N and irrigation on yield were restricted mainly to the rates of 200 and 400 pounds N per acre. Yield differences because of clipping frequency were greater at the higher soil moisture regimes and higher N rates. Average yields ranged from 1.19 tons per acre of oven‐dry forage with no N at the high moisture regime clipped at 21‐day intervals to 9.88 tons at the 1200‐pound N rate at the high moisture regime clipped at 32‐day intervals.

Nitrogen content of the above‐ground portion of the plants increased with clipping frequency and rate of N, but was not affected by soil moisture regime. From 20 to 89% of the applied N could be accounted for in the above‐ground portion of the plants.
Physical Soil Amendments, Soil Compaction, Irrigation, and Wetting Agents in Turfgrass Management I. Effects on Compactability, Water Infiltration Rates, Evapotranspiration, and Number of Irrigations1
Authors: Morgan W. C. , Letey J. , Richards S. J. , Valoras N.
Published: July 2010

Unamended soil and soil amended with peat, lignified redwood, and calcined clay were used to grow common bermudagrass in a greenhouse experiment. Two compaction treatments, 2 wetting agent treatments, and 2 irrigation programs were superimposed on each of the soil materials for a total of 32 treatments. Water infiltration rates were in the general order of unamended soil < peat < lignified redwood = calcined clay amended soil. Compaction decreased the infiltration rate of unamended and peat amended soil, but had no effect on the other two soil mixes. Wetting agent increased the infiltration rate into unamended soil. Soil compactability was in the order unamended soil > peat > lignified redwood > calcined clay amended soils. Soil compactability was greater under set schedule irrigation as compared to tensiometer guided irrigation. Wetting agent reduced the compactability of peat. Evaportranspiration and number of irrigations were greater under set irrigation as compared to tensiometer guided irrigation. Other results of this experiment will be presented in subsequent papers.
Sprouting of Coastal Bermudagrass Stolons1
Authors: Beaty E. R.
Published: July 2010

Sprouting of ‘Coastal’ bermudagrass sprigs harvested at monthly intervals between October 1, 1953, and February 1, 1954, averaged 94.5%. Sprigs planted the day harvested on the average sprouted 96.0% and sprigs stored for 20 days averaged 94.75%. Sprigs stored in moist sawdust at 70F initiated shoot and root development during storage. These shoots were extremely succulent and would be subject to sprig damage at planting. Sprigs stored at 40F had no shoot development, but sprouting was slightly reduced. A commercial preparation of 3‐indole acetic acid did not increase sprouting or root development.
Soil Water and Nitrogen Influence on Growth and Fruiting of a Cytoplasmic Male‐Sterile Corn Hybrid and Its Fertile Counterpart1
Authors: Bruce R. R. , Sanford J. O. , Myhre D. L.
Published: July 2010

The grain yield and several yield components of a cytoplasmic, male‐sterile, single cross, corn hybrid and its fertile counterpart were measured in relation to imposed soil water tension regimes and applied nitrogen levels. The male‐sterile strain consistently yielded more grain than its fertile counterpart, primarily because of the greater number of second ears produced. A maximum soil water tension of nearly 6 bars, imposed during the fruiting period, significantly accentuated the observed difference in ear production. At the 6‐bar maximum soil water tension imposed during fruiting, the ear length and diameter of male‐sterile corn were significantly greater than those of the male‐fertile; however, at the 0.3 bar maximum soil water tension imposed during fruiting, ear dimensions of the two strains were similar. Although the sterile strain consistently produced a greater number of ears under all conditions of these experiments, reduced levels of nitrogen and soil water more seriously affected ear diameter and length of the fertile strain.
Effect of Seeding, Rate, Fall Disking, and Nitrogen Level on Stand Establishment of Crimson Clover in a Grass Sod1
Authors: Knight W. E.
Published: July 2010

abstract

Five rates of unhulled crimson clover seed were overseeded in a 'Coastal' bermudagrass sod in June to simulate natural reseeding. Satisfactory volunteer stands and yields of crimson clover were produced for 3 years in a Coastal bermudagrass sod when the quantity of seed shattered in the spring was 40 pounds or more per acre. As the clover seeding rate increased from 5 to 80 pounds per acre, the yield of clover increased as well as the yield of grass following the clover. Annually fall‐seeded clover at the rate of 30 pounds per acre was equivalent to the 80 pound simulated reseeding rate.

Under the conditions of this test, fall disking caused highly significant reductions in clover yield with a greater reduction on a percentage basis at the lower seeding rates. The average reduction in clover yield from disking was 760 pounds of dry matter per acre over the 3‐year period. The average effect of fall disking on grass yields was negative but not significant.

Nitrogen reduced both stands and subsequent yields of the clover component; however, the average nitrogen effect was not significant. Highest total yield was produced by the 80‐pound simulated reseeding rate of clover with grass fertilized with 200 pounds of N per acre without fall disking. Crimson clover increased total forage production by 27% when 200 pounds of N was applied to the grass and by 63% when no nitrogen was applied. The clover extended the grazing season 6 to 8 weeks and the additional forage was produced with minimum competitive effect between the grass and the clover.
Effect of Decortication and Fungicide on Performance of Table Beet Seed1
Authors: Peck N. H. , Clark B. E. , Natti J. J.
Published: July 2010

abstract

Decortication of table beet seedballs had no adverse effects on seed germination, seedling growth, and performance of Arasan and Dexon seed treatments. Under dry soil conditions Arasan and Dexon delayed seedling emergence. Dexon also reduced stands. Under moist soil conditions, Arasan and Dexon produced significantly more seedlings than did untreated seedballs. Most of the interactions between degree of decortication, seedball size, and fungicide treatment were not statistically significant. However, variable soil moisture conditions contributed to significant interactions between planting dates and fungicide or seedball size in field tests. Seedling emergence in growth chamber tests in pasteurized sand gave the most accurate prediction of seedling emergence under field conditions.
Coated Urea, Thiourea, Urea‐Formaldehyde, Hexamine, Oxamide, Glycoluril, and Oxidized Nitrogen‐Enriched Coal as Slowly Available Sources of Nitrogen for Orchardgrass1
Authors: Beaton J. D. , Hubbard W. A. , Speer R. C.
Published: July 2010

Yields, N uptake, and apparent recovery of applied N were determined for seven harvests of orchardgrass in the growth chamber following one surface application of several sources of N applied at rates of 56, 112, 225, and 450 mg of N per pot. Apparent recovery of N from the various sources decreased in the following order: coated (dicyclopentadiene copolymer) urea (75%) = ammonium nitrate (74%) > thiourea (690/0) > oxamide‐fine (65%) = oxamide −8 +14 (65%) > urea plus thiourea (63%) > hexamine (59%) > glycoluril (49%) > urea formaldehyde (41%) > ammonium salt of oxidized nitrogenenriched coal (39%).

Yield and N uptake in the first harvest were greatest with ammoniumn itrate, urea, urea plus thiourea, and finely divided oxamide. Glycoluril and coated urea produced the highest yields and N uptake in the second and third harvests. In the later stages of cropping, yields and N uptake from the urea‐formaldehyde and thiourea treatments increased and, in the final four harvests, the results obtained with these two sources were among the highest.

Thiourea depressed yield of orchardgrass when applied at the 450 mg of N rate. However, the yield of this treatment was still much greater than that of the control.
Growth and Phosphorus Uptake by Corn as Influenced by Phosphorus Placement1
Authors: Garg K. P. , Welch L. F.
Published: July 2010

Mixed, banded, and with‐seed placements of P were investigated during early growth stages of greenhouse corn. Forage yield, percent P, and yield of P were used to evaluate the three placement methods at 14, 21, and 28 days from planting.

Percent seed emergence did not differ among the placement methods. Yield of forage, percent P, and yield of P were greater when P was placed in contact with the seed than when it was either mixed or banded. Mixed and banded placement gave the same forage yield. Percent P was greater with mixed than with banded placement for the 14‐ and 21‐day harvests, but this situation was reversed at the 28‐day harvest. Yield of P was affected in the same manner as percent P with respect to mixed and banded placement.

P rates, P placement, and climatic factors that may differ between this greenhouse study and field trials, and their possible effects on the results obtained are discussed.
Effects of Canopy Arrangements on Light Interception and Yield of Soybeans1
Authors: Shaw R. H. , Weber C. R.
Published: July 2010

Leaf and branch arrangement simulating various degrees of lodging produced significant changes in light interception and yield of soybeans. For the 3 years of the experiment, maximum light penetration occurred with a moderate amount of plant spread simulating a small but definite amount of lodging. Generally, the largest part of the light interception occurred in the outer 15 to 30 cm of the plant canopy. Greater light penetration, resulting in a greater amount of the plant canopy having light intensity above 150 ft‐c, generally resulted in greater yields. A photographic technique involving the evaluation of leaf area in the sun was closely related to yield but found to be too time consuming for practical use. Greater oil content was generally associated with greater light penetration. The effect of shading of adjacent rows was greater in 1‐m row spacing than on 1.5‐m row spacing.
Presence and Persistence of Phytotoxic Substances in Wheat, Oat, Corn, and Sorghum Residues1
Authors: Guenzi W. D. , McCalla T. M. , Norstadt Fred A.
Published: July 2010

Wheat, oat, corn, and sorghum residues, collected at time of harvest for each crop, contained water‐soluble materials that were toxic to growth of wheat seedlings. The order of increasing toxicity was wheat, oat, corn, and sorghum residues. To evaluate the potential toxicity of a residue, the state of decomposition must be considered. Wheat and oat residues essentially contained no water‐soluble toxic components after 8 weeks of exposure to field environmental conditions. Corn and sorghum residues had considerably more toxic materials at harvest and required about 22 to 28 weeks of decomposition before the water‐soluble portion of the residues was relatively nontoxic. Tests of nine wheat varieties showed that the toxicity of wheat straw water extracts to germination and growth of wheat seedlings differed among varieties.
Relative Efficiency of Several Zinc Sources for Corn (Zea mays L.)1
Authors: Shukla U. C. , Morris H. D.
Published: July 2010

Corn was grown on two soils in greenhouse experiments to determine the relative efficiency of various Zn sources at different levels of lime and P applications. Plant deficiency symptoms, growth, (oven‐dry weight of corn tops), height, Zn content, and Zn uptake were evaluated.

Corn growth was increased by Zn fertilization on both soils. No differences were found among the Zn sources on the Red Bay soil where only a slight response to Zn was obtained. Increases in growth up to 154% were obtained from Zn fertilization on the Norfolk soil. ZnSO4 was slightly more effective than ZnO or Zn chelate and organic (polyflavonoid) Zn was the least effective source. ZnSO4 and ZnO were equally efficient or superior to chelate and organic Zn in increasing the Zn content and uptake of corn on the basis of amounts used.

Liming resulted in decreased corn growth, plant Zn content, and Zn uptake, especially when no Zn was applied. High P fertilization decreased the Zn content of corn but tended to increase growth when applied with Zn.
Coastal Bermudagrass Forage Production and Chemical Composition as Influenced by Potassium Source, Rate, and Frequency of Application1
Authors: Adams William E. , White A. W. , McCreery R. A. , Dawson R. N.
Published: July 2010

The influence of K source, rate, and frequency of application was studied on intensively managed ‘Coastal’ bermudagrass grown on Cecil sandy loam soil.

The N, P, and K contents of the forage and the forage production were not influenced by the chloride or sulfate source of K. The 185 kg/ha K rate applied as KCl in 4 equal splits—at the initiation of spring growth and after each of the first 3 harvests—produced about 15,700 kg/ha of forage and the most efficient K utilization. Efficiency was reflected by (i) more uniform seasonal forage distribution and (ii) a more uniform K content (average 1.5%) throughout the growing season as contrasted with applying all the K in the spring. This management practice of splitting the K application increased the kilograms of forage produced per centimeter of rainfall by 14% and the efficiency of applied K by 14%.

The K‐Ca‐pyrophosphate source produced significantly more forage with a significantly lower K content than either the sulfate or chloride sources of K.

One hundred eighty‐five kg/ha of K applied in four equal splits, rather than at one time, doubled the exchangeable K in the surface 15 cm of soil, produced earlier spring growth of the Coastal bermudagrass, and a higher forage yield in the first harvest.
Evaluation of Tall Fescue Pasture under Different Fertilization Treatments1
Authors: Reid R. L. , Odhuba E. K. , Jung G. A.
Published: July 2010

The influence of fertilizer treatment and growth stage on the composition and nutritive value of tall fescue grazed or fed as cut herbage to sheep was examined in first growth and regrowth pasture. Analysis of clipped herbage showed effects of growth stage and fertilizer treatment on plant content of protein, fiber fractions, soluble carbohydrate and certain macro elements, but little consistent effect on trace minerals. With clipped herbage, fertilizer and growth stage altered dry matter and protein digestibility. Fertilizer had little effect on ad lib. intake; intake declined with advancing maturity in the first growth herbage, but there was no effect of date of cutting on intake in the regrowth trials. The dry matter digestibility of grazed herbage was calculated by use of fecal N as an indicator in “local” regressions. The relationship between digestibility and fecal N was found to be affected by growth phase (first cuttings vs regrowth), but not by fertilizer treatment. Calculated dry matter digestibility coefficients averaged 2% higher for grazed than for clipped herbage. Estimated intake values for grazing sheep indicated that cutting date had no effect on intake within first growth or regrowth trials, but that herbage fertilized with higher levels of nitrogen, or nitrogen plus phosphorus, was consumed in greater amount than nonfertilized grass, or grass treated with phosphorus or potassium alone. Grazing sheep in palatability trials showed a marked preference for fescue fertilized with nitrogen, or nitrogen plus phosphorus. Correlation analyses of nutritive criteria with plant composition showed significant relationships between the dry matter digestibility of clipped or grazed herbage and the content of dry matter, crude protein or fiber fractions, but little apparent effect of most plant components on intake.
An Unusual Feeding Habit to Measure Differences in Damage to 81 Latin‐American Lines of Corn by the Fall Armyworm, Spodoptera frugiperda (J. E. Smith)1
Authors: Wiseman B. R. , Wassom C. E. , Painter Reginald H.
Published: July 2010

The fall armyworm, Spodoptera frugiperda (J. E. Smith) deviated from its reported feeding habits at St. John, Kansas, in 1964. Damage to 81 Latin‐American lines of corn (Zea Mays L.) was evaluated on the basis of larval feeding in the area where the leaf‐sheath joins the node. Dislodged leaves sometimes resulted. This injury was used to detect differences in the response of the lines. ‘Cuba Honduras 46‐J’ and ‘Eto Amarillo’ were the least damaged of the 81 lines tested. The Antigua lines probably carry a higher degree of resistance based on their high ranking in this and other tests.
Influence of Primary and/or Adventitious Root Systems on Wheat Production and Nutrient Uptake1
Authors: Boatwright G. O. , Ferguson Hayden
Published: July 2010

Spring wheat (Triticum aestivum “Thatcher”) was grown under greenhouse conditions to evaluate the importance of individual root systems under two levels of P and two soil water regimes in the fertilizer zone. A technique was developed whereby plants could be grown with complete root systems (primary plus adventitious), with only primary roots, or with only adventitious roots.

Plants that developed only primary or only adventitious roots initiated late tillers just before reaching maturity. Since plants utilizing both root systems failed to initiate late tillers, it appears that late tillering is related to root development rather than to a soil water or P fertility factor. Early tillering under P fertilization was significantly greater when plants developed both root systems than when only primary or only adventitious roots were utilized. Phosphorus fertilization did not increase tiller formation unless both root systems were present.

Grain yields were significantly greater when plants developed both root systems than when either individual root system was utilized. Plants with only adventitious roots yielded significantly more grain than those with primary roots only. This suggests that adventitious roots are more physiologically active than primary roots. Phosphorus fertilization significantly increased grain yields, irrespective of root development. The dry fertilizer zone resulted in decreased wheat yields when plants developed both root systems, but yields from plants with only primary roots were not affected by the dry fertilizer zone.

Nitrogen and P translocation into the grain was significantly greater when plants developed both root systems than when plants were grown with incomplete root systems.
Changes in Organic Matter and Bulk Density with Depth Under Two Cropping Systems1
Authors: Davidson J. M. , Gray Fenton , Pinson D. I.
Published: July 2010

Measurements of soil organic matter and bulk density with depth after 24 years of continuous cotton and continuous lespedeza were significantly different. Continuous cotton resulted in a lower organic matter content in the surface soil than continuous lespedeza, while the soil bulk density under cotton was considerably higher than lespedeza at the 12.7 to 20.3‐cm depth.

The maximum compaction that could be given the Norge loam, a Reddish Prairie soil, when subjected to a constant load, was directly related to the amount of organic matter present in the soil. Maximum compaction was extremely sensitive to small changes in organic matter caused by different cropping practices. Data also shows maximum compaction occurs on a Norge loam at a soilwater pressure of 1/3‐bar, or at what is frequently called “field capacity”.
Effect of Soil Moisture Regime on Nodulation of Inoculated Peanuts1
Authors: Shimshi D. , Schiffmann J. , Kost Y. , Bielorai H. , Alper Y.
Published: July 2010

A two‐year investigation on the effect of soil moisture regime (as conditioned by irrigation timing) and the depth of placement of inoculum on peanut inoculation was carried out in the northern Negev area of Israel. The inoculation was performed at planting time by introducing the bacterial suspension into the moist soil. The repeated drying‐out of the upper soil layers during irrigation cycles did not inhibit the process of nodulation. The placement of the inoculum at a depth of 12 cm resulted in poorer nodulation than at a depth of 3–4 cm, despite the higher soil moisture at the greater depth. Inoculation maintained a more favorable supply of nitrogen to the plants than did a 85 kg/1000 m2 application of ammonium sulfate and resulted in higher yields and better quality of peanuts.
One Hundred Forage Seeding Mixture1
Authors: Jackobs J. A.
Published: July 2010

Forage mixtures consisting of one to three legumes and of one to three grasses were established in four experiments at three locations in Illinois. The legumes were alfalfa, red clover, and Ladino clover. The grasses were timothy, smooth brome, and orchardgrass. In three trials the forage was harvested as hay and in the fourth trial it was grazed. Forage yields and botanical composition were studied.

Alfalfa and orchardgrass had the greatest influence on the performance of the mixtures. When alfalfa was added to a mixture the total yield of forage was increased because the decrease in grass was not as great as the increase in the legume. When orchardgrass was added to a mixture the grass component was increased but there was a comparable decrease in the legume so the total yield remained about the same. The amount of alfalfa and orchardgrass seed in a mixture required to achieve most of the effects of these species was surprisingly low.
Efficient and Inefficient Use of Iron by Two Soybean Genotypes and Their Isolines1
Authors: Brown J. C. , Weber C. R. , Caldwell B. E.
Published: July 2010

Iron‐efficient ‘Hawkeye’ and iron‐inefficient PI‐54619‐5‐1 soybean genotypes and their isolines A62‐9 (iron efficient) and A62‐10 (iron inefficient) were grown comparatively on soils and solution cultures. There was a differental response in the iron‐efficient soybeans. A62‐9 was less efficient than Hawkeye. This loss in efficiency was related to a loss in the ability of A62‐9 to reduce Fe+++ to Fe++ at the root. The four genotypes differed in their ability to reduce iron: Hawkeye > A62‐9 > PI 54619‐5‐1 ≥ A62‐10.

A lowered pH of the growth medium, a concomitant release of reducing substance by the roots, and the subsequent reduction of iron at the root are associated with the absorption and translocation of iron. Translocation of citrate in the stem exudate of the four genotypes relates most nearly to the available iron supply.
Studies of Water Requirements of Horticultural Crops: II. Influence of Drought at Different Growth Stages of Onion1
Authors: de Lis B. R. , Ponce I. , Cavagnaro J. B. , Tizio R. M.
Published: July 2010

Two years of field experiments with onion crops (Allium cepa, L.) show that this plant is differentially sensitive to drought in each stage of its vegetative cycle. Drought at the seedling stage increases the rate of foliar emergence, produces a greater number of leaves, accelerates bulb formation by 15 days, and increases the final weight as compared with the check (no significant difference). When drought occurs at the beginning of the bulb formation, it causes a delay in foliar emergence, a smaller number of leaves, and a decrease in bulb weight (a significant difference as compared with the check). In other stages of the cycle (post‐transplanting, and 50 and 100% of the bb's weight), the drought does not cause significant damage to the plant's growth.
The No‐Tillage System for Corn (Zea mays L.)1
Authors: Jones J. N. , Moody J. E. , Shear G. M. , Moschler W. W. , Lillard J. H.
Published: July 2010

Corn (Zea mays L.) grown under the no‐tillage system was compared with that grown under (1) systems involving increased amounts of tillage for 2 years, and (2) conventional turnplow tillage over a 6‐year period.

Plant growth and yield of corn generally increased with decreasing degrees of tillage in the 2‐year test. Yields from no tillage during the 6‐year period were comparable to or ranged from 18 to 39% above yields from conventional turnplow tillage. Soil moisture measurements indicated that the dead sod mulch provided by the no‐tillage procedure was highly effective in reducing evaporation and runoff from the soil surface.
Effects of Clipping Compared to Grazing of Ladino Clover‐Orchardgrass and Alfalfa‐Orchardgrass Mixtures1
Authors: Bryant H. T. , Blaser R. E.
Published: July 2010

Clipped and grazed plots with similar defoliation intensities were sampled with a sickle bar mower for yield on the same day. The clipped plots were trimmed with the mower and the grazed plots grazed by cows the same day yield samples were taken. After each grazing the manure was removed and the ungrazed forage around urine spots trimmedd with a hand sickle.

Herbage yields were higher under clipping than under grazing. Grazing had less effect on yield of alfalfa‐orchardgrass than on yield of Ladino clover‐orchardgrass. The harmful effect of grazing was not permanent. Higher yields of Ladino‐clover‐orchardgrass were obtained under both clipping and grazing by defoliating to 1.9 cm compared to 6.4 cm. Highest and lowest yields of alfalfa‐orchardgrass were obtained on the least and most frequently defoliated plots, respectively, under both clipping and grazing.

Estimating potential grazing yields by clipping may lead to predicting inflated yields. The grazing technique used appears suitable for studying how the animal affects plants under different grazing pressures.
Effect of Corn (Zea mays L.) Stover Mulch on No‐Tillage Corn Yield and Water Infiltration1
Authors: Triplett G. B. , Van Doren D. M. , Schmidt B. L.
Published: July 2010

Corn was grown for 3 years on Wooster silt loam, a soil on which the yield response of corn to cultivation exceeds that attributable to weed control. Treatments included conventional preplant tillage (plowing, disking) and no preplant tillage with three corn stover residue levels, 5% cover (stover removed), 45% cover (stover left in place), and 70% cover (double level of stover). Except for the first year when the tilled plots were not cultivated, grain yields with 45% cover (6,170 kg/ha) equalled the tilled check (5,970 kg/ha). Yields of treatments with 5% cover were significantly lower (4,770 kg/ha) than the tilled treatment and significantly higher with 70% cover (6,625 kg/ha). Soil moisture determined with gypsum blocks during the last 2 years was greater with increasing amounts of soil cover during the growing season. Soil cover did not increase during the experiment, even on treatments receiving double residue. At the end of the third year, water infiltration as determined with a sprinkling infiltrometer was significantly greater with 80% cover than for the other treatments. Results from these experiments indicate that mulch protection which may be readily available from previous crop residues is necessary to maintain no‐tillage corn grain yields on this and similar areas of Wooster silt loam. The beneficial effects of the mulch seem to be associated with increased soil moisture.
Influence of Row Spacing and Nitrogen Fertilization on Grass Seed Production1
Authors: Canode C. L.
Published: July 2010

The seed production capabilities of five species of cool‐season grasses as influenced by three row spacings and three nitrogen rates were determined for a 5‐yr period. The conclusions here are based on the 4‐ or 5‐yr cumulative average seed yields.

Kentucky bluegrass produced more seed in 30‐ and 60‐cm rows. Crested wheatgrass and smooth bromegrass seed production was higher in 60‐cm rows, but for smooth bromegrass the difference in seed yield for the 60‐cm rows was not significantly higher than those of the 90‐cm rows. Orchardgrass produced more seed in the 90‐cm rows. Row spacing did not influence the seed yields of red fescue.

Kentucky bluegrass and orchardgrass responded with more seed when fertilized with nitrogen at 90 or 112 kg/ha. Crested wheatgrass produced more seed with 112 kg/ha of nitrogen, but the differences were only significant in the 4‐yr average yields. Nitrogen rates over 67 kg/ha did not increase the seed yields of red fescue and smooth bromegrass.

The 90‐cm rows resulted in heavier seed than that produced in 60‐ and 30‐cm rows. The 112 kg/ha of nitrogen increased seed weight in red fescue, but decreased seed weight of smooth bromegrass. Nitrogen rates did not influence the weight of crested wheatgrass seed.
Influences of Several Management Practices on Growth Characteristics and Available Carbohydrate Content of Smooth Bromegrass1
Authors: Paulsen Gary M. , Smith Dale
Published: July 2010

Herbage yields of bromegrass (Bromus inermis Leyss.) grown without alfalfa were favored by infrequent cutting (3 cuts) primarily because spring growth yields were increased. Nitrogen fertilizer (168 kg/ha) increased bromegrass yields by increasing the number of tillers and rapidity of regrowth after cutting. Herbage yields of bromegrass plants grown with alfalfa were favored by frequent cutting (5 cuts) because fewer shoot apices were removed by frequent cutting and because alfalfa was less competitive.

Frequent cutting decreased slightly the percentage of total available carbohydrates (TAC) accumulated between cuttings in the stem bases of bromegrass. Nitrogen fertilizer increased depletion of TAC after cutting, but did not affect the maximum level accumulated. Association with alfalfa decreased markedly the percentage of TAC in bromegrass during the growing season. High levels of TAC were present under all the treatments when growth ceased during late autumn.
Effect of Nitrogen to Phosphorus Atom Ratio of Ammonium Phosphates on Emergence of Wheat (Triticum vulgare)1
Authors: Stevenson C. K. , Bates T. E.
Published: July 2010

Ammonium phosphates providing five N:P atom ratios (1.00, 1.25, 1.50, 1.75, and 2.00:1) were applied in solution in the row with wheat seed at planting in greenhouse experiments. The soils used were Oneida clay loam (CEC 18.3 meq/100 g) and Fox sandy loam (CEC 8.2 meq/100 g) each adjusted to pH levels ranging from 5.4 to 7.4. Soil pH, over the range studied, had no effect on emergence with any of the ammonium phosphate materials tested. Neither early nor final emergence changed when the N:P atom ratio was varied in the clay loam soil when the molarity of the fertilizer solution was held constant (equal rates of P but varying rates of N). In the sandy loam soil early emergence was markedly lower with high N:P atom ratio materials than with low ratio materials. Final emergence showed the same trend as early emergence with the sandy loam soil but differences between materials were much smaller. The difference in results between the two soils is attributed to the effect of cation exchange capacity on the toxicity of ammonia in the soil.
Corn Yield and Economic Optima for Nitrogen Treatments and Plant Population Over a Seven‐Year Period1
Authors: Colyer Dale , Kroth Earl M.
Published: July 2010

Response of corn (Zea Mays L.) yield to nitrogen applications at various planting rates were determined for two soil types over a seven‐year period. Regression analysis was used to determine response surfaces, maximum and economic optimal treatments and yields. Response curves and production surfaces were constructed from the regression data. Significant differences in responses and optimal treatments were found from year to year and between sites. Optimal nitrogen treatments varied from 21.4 to 202.1 kg/ha and optimal planting rates from 12,189 to 54,135 plants/ha. A function from data aggregated over seven years indicated that the optimal rates would be 120 kg/ha of N and 37,787 plants/ha.
A Precision Weighing Lysimeter for Row Crop Water Use Studies1
Authors: Ritchie Joe T. , Burnett Earl
Published: July 2010

A relatively simple and economical weighing lysimeter specifically designed for evaluating hourly row crop water use under dryland conditions has been developed and tested. The lysimeter soil container is 1.83 m (6.0 ft) square by 1.22 m (4.0 ft) deep. This allows a representative rooting profile for two rows of crop spaced 0.92 m (3.0 ft) apart and also allows normal soil shrinkage cracks to form within the soil mass. The thin soil container and retaining tank walls are separated by a 10‐mm air gap, resulting in a surface disturbance of only 4.5% of the lysimeter area. Soil water suction at the bottom of the soil container is controlled. A commercially available floor stand tank scale lever assembly is used to transfer up to 600 kg of the total lysimeter weight to a precision strain gauge load cell, the remainder being counter‐balanced under the lysimeter. The sensitivity of the system (± 0.025 mm equivalent water weight change) is adequate for short‐period evaporative flux measurements. The electrical output signal from the load cell can be measured remotely, minimizing site disturbance. The weighing mechanism has suitable utility for other weighing lysimeter applications.
Management of Land Diverted from Crop Production. I. Perennial Forages1
Authors: Robinson R. G.
Published: July 2010

abstract

Alaflfa (Medicago sativa L.), alfalfa‐brome (Bromus inermis Leyss.), red clover (Trifolium pratense L.), red clover‐timothy (Phleum pratense L.), sweetclover (Melilotus alba Desr.), and sweetclover‐timothy were maintained at Rosemount, Minn. under three management systems— removal of forage from the plots, mowing and leaving forage, and chopping and leaving forage. Within each management system, comparisons were made of one, two, and three cuttings per year. Uncut plots were included in each replicate. After 2 to 5 years of the management and cutting treatments, corn (Zea mays, L.) was grown for 2 years to determine residual effect of treatments on corn production using seven methods of land preparation.

Comparison of forage removal with nonremoval—Removal reduced stands of timothy but not those of other forages, slightly increased weed control, reduced soil fertility, and reduced grain production 636 to 1168 kg/ha in the first 2 years of corn.

Comparison of mowing with chopping—Mowing and chopping effects were similar on forage stand, forage growth, weed control, and corn yield except that chopping sweetclover resulted in higher corn yields than mowing.

Comparison of cutting treatments—Cutting favored growth of alfalfa, red clover, and foxtail (Setaria glauca (L.) Beauv. and viridis (L.) Beauv.) and injured bromegrass, timothy, and quackgrass (Agropyron repens (L.) Beauv.). Uncut bromegrass‐alfalfa gave the densest ground cover and best weed control. Without bromegrass or timothy present, cutting was essential for weed control, and two cuttings were best.

Comparison of herbicide‐tillage methods of land preparation for corn—Plowing in July and spraying in September gave best weed control.
Comparison of Growth Stages of Sorghum Forage Types as to Yield and Chemical Composition
Authors: Worker George F. , Marble Vern L.
Published: July 2010

A 2‐year study of harvesting three types of forage sorghum — sudangrass, sorghum‐sudangrass hybrids, and sorgo — at pasture, boot, flower, and soft‐dough stages was undertaken to evaluate dry‐matter production, chemical composition, and digestibility predicted from chemical analyses.

Dry‐matter yields generally increased in all types as harvest was delayed, with sorgo making the largest increase at the soft‐dough stage.

Percent ash, crude protein, and fat decreased as harvest was delayed with little difference occurring between forage types. All cultivars declined in fiber when harvested after the flower stage. Total sugar percent increased as harvest was delayed for all forage types.

Sudangrass and sorghum‐sudangrass TDN percent was lowest when cut at flower stage of maturity, whereas the sorgo steadily increased from the earliest harvest to the latest.

Forage quality, except for crude protein which decreased sharply as harvest was delayed, was approximately equal for all forage types. Dry‐matter production varied considerably by forage types and stage of harvest indicating the utilization of sudangrass for pasture or green chop; sorghum‐sudangrass hybrid for pasture, green chop, or silage; and sorgo for silage.
Evidence of Genetic Resistance to Aluminum Toxicity in Wheat (Triticum Aestivum Vill., Host)
Authors: Kerridge P. C. , Kronstad W. E.
Published: July 2010

A preliminary study was made involving the nature of inheritance of Al toxicity in wheat. The difference in tolerance between the susceptible and moderately resistant varieties tested appears to be controlled by a single dominant gene.
Influence of Crop Sequence, Nitrogen Fertilizer and Herbicides on Weed Seed Populations in Sugar Beet Fields1
Authors: Dotzenko A. D. , Ozkan M. , Storer K. R.
Published: July 2010

The crop sequence in which sugar beets followed beans had lower weed seed populations than did sugar beets following barley and corn. The rate and time of application of nitrogen fertilizer had a significant effect on weed seed numbers in sugar beet fields. Where high levels of N were applied, high densities of weed seed occurred. Chemical weed control treatments significantly reduced populations of all weeds studied when compared to mechanical cultivation treatments. Significant differences between interactions were found for N fertilizer and crop sequence, weed control and crop sequence and weed control and N fertilizer.
Cause of Differential Susceptibility to Zinc Deficiency in Two Varieties of Navy Beans (Phaseolus vulgaris L.)1
Authors: Ambler J. E. , Brown J. C.
Published: July 2010

Two navy beans (Phaseolus vulgaris L.) varieties, ‘Sanilac’ and ‘Saginaw,’ were grown in soil, solution culture, and split medium. Plant growth and Fe, P, and Zn uptake were compared with differential Zn deficiency in each of the three media. In general, Fe and P aggravated Zn deficiency. Differential absorption of Fe and P by the two varieties appears to be the cause of differential susceptibility to Zn deficiency. Sanilac took up more Fe and P than Saginaw in a growth medium relatively low in Zn.
Potential Yield of Corn as Affected by Planting Date
Authors: Pendleton J. W. , Egli D. B.
Published: July 2010

A field experiment was conducted at Urbana, I11., to determine the grain yield potential of corn plants developing during the period of maximum day length as compared to other plants developing later in the season. A high management level including high fertility and adequate soil moisture was maintained.

Plants started in the greenhouse, transplanted to the field April 19 when approximately 15 cm tall, and pollinated June 15, yielded no more grain than plants started as seed in late April and pollinated July 8. Seedings made in the field May 14 and May 31 gave yield reductions of 103 kg/ha day as compared to the yield of the April 30 seeding. Stalk strength as measured by resistance to crushing was found to decrease with date of planting from April 19 to May 31.
Comparison of Indexes Relating Plant Response to Soil Moisture Status1
Authors: Rawitz E. , Hillel D. I.
Published: July 2010

The response of container‐grown sunflowers and snapbeans to soil moisture status was measured in a growth chamber and related to four soil moisture indexes. Drymatter yield was related to pre‐irrigation and to mean integrated soil moisture content and capillary suction. When related to moisture content indexes, yield appeared as a continuously rising function of moisture content, with a fairly constant slope. When related to moisture suction indexes, yield decreased very sharply with increasing capillary suction in the low‐suction range. When the maximum capillary suction index was used, most of the yield depression occurred at suctions lower than two bars, after which yield decreased at a much lower and constant rate to the 15‐bar suction. Among the four indexes examined, the maximum capillary suction index was found to be the most convenient for current control of soil moisture regimes. Application to results of fleld irrigation experiments indicates that it may be used under field conditions as well as with container‐grown plants. Since plant performance is a result of interaction between many factors in addition to soil moisture suction, an index based on a single factor cannot uniquely relate plant response to this factor. The maximum capillary suction index can, however, serve as a practical and simple tool when the effect of modifying factors is known or can be held constant.
Yield and Quality of Corn Silage as Influenced by Harvest Height1
Authors: Cummins D. G. , Burns R. E.
Published: July 2010

Yield and quality variations of corn silage associated with different harvest heights, and the yield and quality contributions of various plant segments below the ear were determined over a 3‐year period, 1966‐68, at Experiment. Ga. An increase in harvest height from 15 to 90 cm from the soil level decreased forage yields from 13.7 to 11.2 mt/ha, while in vitro dry matter digestibility (IVDMD) increased from 45.1 to 51.1%. The IVDMD for 15‐cm plant increments increased from 26.0% for the 15‐30 cm portion to 34.7% for the 75‐90 cm portion below ear. Harvested digestible dry matter (IVDMD ✕ forage yields) was 6.0, 6.0, and 5.9 mt/ha for the 15‐, 45‐, and 90‐cm heights, respectively. Although, total yields decreased with increased harvest height the increase in quality offset this loss in terms of harvested digestible dry matter.
A Linear Rule for Direct Nondestructive Leaf Area Measurements1
Authors: Grimes Donald W. , Carter Lyle M.
Published: July 2010

A ruler was developed with graduations in area units of cm2 from the functional relationship Log10 Leaf Area (cm2) = a + b Log10 Leaf Length (cm). The functional relationship was established for cotton (Gossypium hirsutum L.) by sampling leaves twice during the growing season at different stages of morphologic development. Since the equations for the two sampling dates did not differ appreciably, the ruler was developed from the pooled data.
Soil Moisture Content, Tilth, and Soybean (Glycine max.) Response with Surface and Subsurface Drainage1
Authors: Fausey Norman R. , Schwab Glenn O.
Published: July 2010

Soil properties and soybean response were compared for plots having different levels of drainage. The plots were established on a silty clay lakebed soil in northern Ohio. The soil and crop characteristics compared were: (1) average soil moisture content at four depths in the upper 30 cm during the seedbed preparation period (April and May); (2) soil tilth immediately preceding seedbed preparation as expressed by crust properties and resistance to surface penetration; and (3) stand establishment, root and top growth, and soybean yield. On plots with no drainage, crop stand was sparse and crop growth essentially nil. There were long periods with ponded water, and crusting and adverse structure of the surface soil were much in evidence. Among drained plots, there were no maesurable differences in crust bulk density and soybean stand. Plots having subsurface or combined surface‐subsurface drainage had lower moisture content, less resistance to surface penetration, smaller crust units, taller plants, better developed root systems, and greater yields than plots with surface drainage alone.