bluuebunny/crossref_metadata_2025 huggingface dataset:
Residual Effects of Crop Rotations on Water Intake, Soil Loss, and Sorghum Yield1
Authors: Adams John E.
Published: July 2010

The duration of the residual effects of crop rotations on the fertility and physical condition of montmorillonitic clay soil is not well established. The purpose of this study was to evaluate the residual effects of three crop rotations on water intake, soil loss, soil organic matter, and crop yield during five growing seasons of continuous grain sorghum (Sorghum bicolor (L.) Moench) grown on Houston Black clay soil. Water intake and soil loss were evaluated in the laboratory by the application of water drops at the rate of 10.2 cm/hour from a height of 1 m to the surface of undisturbed soil cores.

Oats (Avena sativa L.)‐grain sorghum and fescuegrass (Festuca arundinacea Schreb.)‐grain sorghum rotations significantly (5% level) increased water intake and reduced soil loss for 20 months after the rotations were discontinued. The sweetclover (Melilotus alba Desr.)‐grain sorghum rotation had no effect on soil loss but had a significant (5% level) residual effect on water intake for 8 months after rotations were discontinued. Grain sorghum rotations with either fescuegrass or sweetclover caused significantly more (5% level) water stable aggregates. However, one growing season of grain sorghum following sweetclover reduced aggregation to near that of soil in continuous grain sorghum. There was no significant change in aggregation in fescuegrass rotation plots after 20 months.

Most of the organic matter accumulated in 10 growing seasons of a sweetclover‐grain sorghum rotation was lost after 5 growing seasons of continuous grain sorghum. Soil organic matter in former grain sorghum rotations with fescuegrass or oats showed no significant change after 5 years of continuous forage sorghum. Grain sorghum yield was significantly greater (5% level) for four growing seasons on the former sweetclover‐grain sorghum plots than on the continuous grain sorghum plots. Nitrogen fertilizer had a significant (5% level) residual effect on continuous grain sorghum yield for 2 years.

The residual effects of previous crop rotations can significantly affect (5% level) water intake and soil loss for 20 months and crop yield for 1 to 4 years after rotations are discontinued. Growing sorghum continuously for 5 years reduced water intake significantly and caused a continuous slow decrease in soil organic matter.
Error Mean Squares of Protein Yield of Alfalfa‐Grass Mixtures Computed by Five Methods1
Authors: Torrie J. H. , Smith Dale , Bellman Susan K.
Published: July 2010

The purpose of this statistical study was to compare the error mean squares of herbage protein yields per hectare computed in five different ways. Herbage yield and protein percentage data were obtained from an alfalfa (Medicago sativa L.)‐grass mixture trial conducted at Arlington, Wisconsin. These comparisons were made to determine the precision of protein analyses made on herbage from a limited number of replications with that based on all four replications.

Method A, using protein percentages and herbage yields from all plots of four replications, gave an unbiased estimate of experimental error for protein yields per hectare. Protein yield by method B was computed from the weighted average percentage protein of replicates 1 and 2 and of 3 and 4, and the herbage yields from all plots of replicates 1 and 2 and of 3 and 4, respectively. Protein yield by method C was computed by using the protein percentages and herbage yields of replicates 1 and 3 and the weighted average protein percentage of replicates 1 and 3 for all plots of replications 2 and 4. Methods B and C were biased and underestimated the experimental error of method A, but the underestimation was small.

Protein yield by method D was computed from the weighted average percentage protein and herbage yields of replicates 1 and 2 and of replicates 3 and 4. By method E, protein yield was computed for each plot in replications 1 and 3 as described for method A. These two methods have only one‐third as many degrees of freedom to estimate experimental error as the other methods in the four‐replication experiment. As compared with method A, methods D and E have a larger standard error of the mean.
Variation in Effectiveness of Supplemental Irrigation on Sweet Corn Yield Components
Authors: Andrew R. H. , Weis G. G.
Published: July 2010

Supplemental irrigation is of increasing importance in the production of processing sweet corn (Zea mays L.) in the humid Midwest. However, wide variation exists for efficiency of irrigation as related to uniformity and quality as well as yield of this crop. The present study was planned to measure the response of major sweet corn yield components to, and their interaction with, irrigation level as related to genotype, plant competition, and season and to provide guidelines for optimum production practice. Six hybrids were grown at three populations (39,000, 49,000, and 59,000 plants/ha) under low and high irrigation levels on droughty sand in central Wisconsin over a 9‐year period. Measurements were made of snapped weight, weight and number of usable husked ears, and percent of usuable ears expressed on a weight and number basis.

There were wide yearly differences between irrigation levels for all yield components. Increase in production at high irrigation was greatest for snapped corn weight (34.3%), intermediate for usable corn weight (29.4%), and lowest for usable ear number (13.5%). The additional water provided by high irrigation increased snapped weight at an average rate of .52 metric tons/ha per centimeter of applied moisture and increased usable weight by .28 metric tons; the greatest effect was in dry seasons, the least in cool seasons. Record yields were achieved under high irrigation when August temperature was highest. Moisture during the period from 2 weeks prior to silking until harvest and from silking to harvest was significantly associated with yield. Under high irrigation snapped weight ranked first at the intermediate population while usable ear weight and number ranked first at the high population. Under low irrigation snapped and usable ear weight but not usable number decreased with population.

Percent usable ears, by weight and number, was highest at the low irrigation with marked hybrid and population differences. The low population at high irrigation increased prolificacy, while the high population at low irrigation increased barrenness. Hybrid‐production practice combinations yielding most also had low coefficients of variability over years. Although high irrigation always increased production, the variation in degree of yield component response emphasizes that efficient production requires coordination of irrigation levels with population, genotype, and season.
Cultivar Differences Among Barley Plants Grown with Different Nutrient Treatments1
Authors: Nittler L. W. , Jensen H. A.
Published: July 2010

Even though cultivar purity determinations of spring barley (Hordeum vulgare L.) can often be made using characteristics of grain or small seedlings, many cultivars are so similar that separation based on such characteristics is not possible. For this reason experiments were conducted to find additional plant characteristics useful for cultivar determinations. Seeds were planted in sand and plants were supplied with a complete nutrient solution or with a solution lacking nitrogen (—N) or phosphorus (—P) and were grown with continuous light. Because seedlings became chlorotic when they were grown without nitrogen or without phosphorus, the complete solution was used on the —N flats after the 14th day and on the —P flats after the 19th day. This permitted continued growth so observations could be made on internode length and tiller number. Five weeks after planting, cultivars differed significantly in length of internodes above first, second, third, fourth, and fifth leaf nodes. Length of first and second leaf internodes was affected greatly by nutrient treatments and cultivars differed markedly. Cultivars also differed significantly in tiller number per plant but not in stem diameter.

Internode length and tiller number of plants grown with special nutrient treatments can be useful along with other characteristics in distinguishing spring barley cultivars.
Uptake and Translocation of a Nonionic Surfactant by Barley
Authors: Valoras N. , Letey J. , Osborn J.
Published: July 2010

Experiments were conducted to determine if nonionic surfactants are taken up and translocated by plants growing in solution or soil containing the surfactant. The effect of surfactant on plant growth was concurrently determined. Barley (Hordeum vulgare L.) and the surfactant 14C‐labeled Soil Penetrant 3685 were used in the study. Surfactant concentrations in solution ranged from 0 to 300 ppm, and the amount of 14C‐labeled surfactant measured in plant shoots increased as the solution concentration increased. There was also a decrease in plant growth as surfactant concentration application increased. Soils were wet with solutions containing 0 to 10,000 ppm surfactant. Surfactant was taken up and translocated from soil systems, but much higher concentrations had to be applied to the soil as compared to solution culture for equal uptake and/or plant damage. Highest concentrations of surfactant occurred in the older leaves and in the tip portion as compared to the base portion of the leaf. Increased plant damage appeared to be associated with increased surfactant concentration in the plant tissue, but a direct cause‐and‐effect relation could not be established from the study.
Chemical Regulation of Grass Growth. II. Greenhouse and Field Studies with Intensively Managedd Turfgrasses1
Authors: Elkins D. M. , Tweedy J. A. , Suttner D. L.
Published: July 2010

Chemical growth retardant treatments have been used on a limited scale to decrease vegetative growth and reduce mowing maintenance requirements of turfgrasses. A number of experimental chemical retardants have been developed recently. Three greenhouse experiments and five field studies were conducted from 1970 to 1972 at Southern Illinois University to evaluate experimental and commercial chemical growth retardants on several species and varieties of intensively managed turfgrass. Seven chemical retardants were tested in the greenhouse with potted Kentucky bluegrass (Poa pratensis L.) and in field studies with Kentucky bluegrass and other species. Treated grasses were evaluated weekly as to growth reduction, and on selected dates as to color maintenance, stand losses, and weed infestations.

MON‐820 (N‐phosphonomethylimini‐diacetic acid) retarded growth of Kentucky bluegrass more than Slo‐Gro (diethanolamine salt of 6‐hydroxy‐3‐(2H)‐pyridazinone; maleic hydrazide or MH). However, losses of the green color often were greater with MON‐820 treatments than with MH treatments. The responses of MBR‐6033 (3‐trifluoromethyl‐sulfonamido‐p‐acetotoluidide) and MON‐845 [N,N‐Bis (phosphonomethyl) glycine] were similar to those of MON‐820 and MH. MON‐139 (phosphonomethylglycine, isopropylammonium salt) and MON‐464 (phosphonomethylglycine, calcium salt) were phytotoxic and caused pronounced color losses and grass stand reductions. High rates of C‐19490 (chemical configuration not released by CIBA GEIGY Corp.) were required to retard grass growth.

Pronounced color losses of the grass, serious stand reductions, and resulting weed infestations occured after use of higher rates of several chemicals. A concurrent herbicide application may be necessary to control weeds in Kentucky bluegrass plots treated with certain growth retardants.

Residual chemical‐retarding effects were noted in autumn‐treated plots when they were evaluated in early spring of the next year. However, few effects were observed in autumn evaluations of spring‐treated plots.

MON‐820 treatments evoked marked growth reduction of a number of Kentucky bluegrass varieties and with varieties of tall fescue (Festuca arundinacea Schreb.), bermudagrass (Cynodon dactylon L.), and zoysiagrass (Zoysia japonica Steud.). Differential varietal and species responses were noted with a given rate of MON‐820. These responses complicate the process of recommending a general chemical rate for a wide array of turfgrasses.

Most experimental and commercial growth retardants tested showed some degree of phytotoxicity on several intensively managed turfgrasses. Their use would be more useful on rough turfgrass areas such as highway roadbanks than on home lawns and similar areas.
Nutritive Characteristics of Kleingrass at Various Stages of Maturity. I. Chemical Evaluations of Experimental Synthetic Varieties1
Authors: Rouquette F. M. , Holt E. C. , Ellis W. C.
Published: July 2010

Previously selected plants for improved lines of kleingrass (Panicum coloratum L.) were evaluated for growth and seed production characteristics. At the initiation of this test, 13 experimental synthetic varieties were available for chemical comparisons of forage quality. This study was conducted to determine if differences existed in percent of neutral detergent fiber (NDF) and NDF components within the available synthetic varieties of kleingrass. The effects of five stages of plant maturity on NDF and its components were also evaluated for each variety. Since kleingrass has an indeterminate type of growth form, plants collected as initial and regrowth forage were harvested when a certain percent of the seed on the most mature kleingrass tillers reached the soft dough stage, but prior to the time of seed maturation. Previously nonharvested cumulative forage was collected at the same chronological age as the regrowth forage. At each of the maturity‐stage dates, plant samples were separated into leaf laminae and stems. Each plant part was analyzed for its neutral detergent solubles:neutral detergent fiber ratio (NDS:NDF). The NDF was then sequentially partitioned into hemicelluloses (HEM), cellulose (CEL), lignin (LIG), and ash. The hemicelluloses were further divided into easily hydrolyzable (EHH) and difficulty hydrolyzable hemicelluloses (DHH). Kleingrass varieties differed in NDS:NDF and NDF components. Leaf:stem ratios ranged from 1:1 to 1:4. By harvesting at a morphological stage prior to seed maturation, the NDS: NDF ratio of leaves and stems in regrowth forage did not vary throughout the study period. Leaf laminae contained approximately 34% HEM and 24% CEL; whereas, stems contained approximately 34% HEM and 34% CEL. With advancing maturity, HEM of leaf laminae increased at the expense of CEL. However, the HEM: CEL ratio of stems remained at approximately 1:1 throughout the collection period. The EHH:DHH ratio changed significantly with plant age as percent EHH increased and DHH decreased. The percent of LIG in both leaves (3.2%) and stems (6.6%) changed with plant age but the buildup of LIG was greatest in stems. Acid‐insoluble ash was influenced by the stage of growth only in leaf laminae and the leaves, with an average of 2.4%, contained four to eight times more ash than did stem sections.
Nutritive Characteristics of Kleingrass at Various Stages of Maturity. II. In vivo and In vitro Evaluations of Selected Varieties1
Authors: Rouquette F. M. , Holt E. C. , Ellis W. C.
Published: July 2010

Recent studies have shown that differences in neutral detergent fiber:neutral detergent solubles ratios (NDF:NDS) exist within experimental synthetic varieties of kleingrass (Panicum coloratum L.), and those varieties which had the highest NDF content were genetically closely related. This investigation was initiated to determine if selected varieties which differed in NDF:NDS also differed in in vitro and in vivo digestibility. The relationships between NDF, components of NDF, and various NDF component ratios vs. in vitro and in vivo digestibility were also studied using three synthetic varieties harvested at four stages of plant growth. Initial and subsequent regrowth forage was harvested as a certain percent of seed reached the soft dough stage, but before seed maturation had occurred. Cumulative growth forage was collected at the same chronological time as the final regrowth harvest date. At each harvest date, analyses were obtained for in vivo digestible dry matter (DDM), in vitro true digestible dry matter (IVDDM), neutral detergent fiber (NDF), digestibility of NDF (DNDF), and NDF components (hemicelluloses, cellulose, lignin, and ash). Percent DDM, IVDDM, and DNDF declined from 62, 74, and 60%, respectively, to 51, 65, and 47%, respectively, with plant maturity. NDF increased from 64% to 71% with plant age and accounted for approximately 92% (r = −0.96**) of the variability associated with DDM. The regression of DDM vs. DNDF resulted in a positive relationship (r = 0.99**). NDF vs. DNDF gave a highly significant negative relationship (r = −0.93**). Cellulose, lignin, and lignin:acid detergent fiber ratio were negatively related to DNDF; whereas, hemicellulose:NDF and hemicelluloses:cellulose ratios were positively related to DNDF. Regression with IVDDM and NDF components and component ratios were of the same magnitude as those relationships with DDM. The level of NDF showed a closer relationship to its digestibility than did any NDF component ratio with DNDF. NDF and DDM showed no difference between varieties, but the IVDMM analyses proved one of the varieties to be superior to the other two.
Flower and Seed Production in Yuchi Arrowleaf Clover1
Authors: Ball D. M. , Hoveland C. S. , Buchanan G. A.
Published: July 2010

Yields of ‘Yuchi’ arrowleaf clover (Trifolium vesiculosum Savi.) seed frequently are reduced by rain‐induced shattering and lodging. Since the normal harvest period in July is usually rainy, earlier flowering should allow earlier seed harvest and therefore reduce shattering losses. Greenhouse, environmental chamber, and field experiments were conducted to study the effect of clipping management, temperature, photoperiod, and growth regulators on flowering and seed production of this winter annual clover.

More than 14 hours of light per day were required for flowering under warm night temperatures. Cool nights delayed flowering under otherwise favorable conditions. There was no obligate cold induction requirement. Clover cut for forage once in mid‐March began blooming earlier, produced more and larger seed heads, and had higher seed yield than clover cut a second time on March 30. Gibberellic acid (GA) increased flower head numbers during May, while GA plus succinic acid 2,2‐dimethylhydrazide (SADH) apparently were synergistic, increasing numbers of flower heads throughout the blooming season. Seed yield was increased over 50% by GA plus SADH.
Effect of High Levels of Nitrilotriacetate on Metal Uptake by Plants Grown in Soil1
Authors: Wallace A. , Mueller R. T. , Alexander G. V.
Published: July 2010

Studies were made to determine if the chelating agent nitrilotriacetate (NTA) when applied to soil in large amounts could cause toxicities to plants by resulting in increased availability of heavy metals. NTA at 2500 ppm applied as the Na salt in soll of pH 6 was slightly toxic to bush beans (Phaseolus vulgarls L., var ‘Improved Tendergreen’). NTA applications at lower rates resulted in increased concentrations of Fe, Zn, Mn, Cu, Mo, Co, Ni, and A1 in leaves of bush beans. Soybeans (Glycine max (U) Merr. Bragg, var. ‘P154619‐5‐1’) grown in Hacienda loam soil at levels from 100 to 1000 ppm had increased concentrations of several heavy metals and also of Ca, K, and Mg in leaves, but there was no apparent yield decrease. Only slight effects could he expected from concentrations likely to be found in effluent water.
Alfalfa Growth on Disturbed and Undisturbed Soil Cores1
Authors: Cassel D. K.
Published: July 2010

Most investigators use disturbed soils or soil materials for nearly all facets of agronomic research. Apparently little thought has been given to how experimental results might differ when undisturbed as opposed to disturbed soils are used. This study was designed to determine difference in alfalfa (Medicago saliva) yield on disturbed and undisturbed soil cores.

Alfalfa was grown in the greenhouse on unfertilized, disturbed and undisturbed soil cores, 30 cm in diameter and 80 cm high. Hecla loamy fine sand, Beotia loam, and Aberdeen loam, representing soils with weak, moderate, and strong grades of soil structure, respectively, were used. Soil water pressure was monitored with tensiometers and the cores were irrigated weekly or biweekly. Significant alfalfa yield differences due to soil structure disturbance were obtained for Hecla and Aberdeen soils. The yield differences cannot be attributed to water relations but possibly may have been due to changes in nutrient availability as a result of soil disturbance.
Effect of Coal Mulch on Crop Yields1
Authors: Fairbourn Merle L.
Published: July 2010

A study was conducted at the Colorado State University Agronomy Research Center, Fort Collins, Colorado to determine if a mulch of 1.0‐ to 3.0‐cm diameter coal pieces would reduce evaporation of soil water and increase soil temperature. Treatments of coal mulch and bare soil were used in both laboratory and field experiments to determine not only the effects on soil water and soil temperature, but also soil fertility and light regime for plants. The coal pieces broke down rapidly and became integrated with the surface soil. The experimental methods showed that the coal mulch effects on soil fertility and light regime were negligible. However, the mulch did increase soil water storage compared with a bare soil. The response appeared to be due to a change in soil porosity of the surface, wetting depth, and soil cracking. Increased soil temperature seemed to be the dominant factor that caused a prominent plant response from a coal mulch. Plants on the coal mulch plots became established rapidly, grew vigorously, and matured early which resulted in higher yields than those from a bare soil treatment. The experiment indicated that low grade coals, soft coals, or coal‐soil mixtures can be used to increase production from agricultural and horticultural plants.
Weed Control Systems for Hophornbeam Copperleaf Control in Peanuts1
Authors: Baldwin Ford , Santelmann Paul , Greer Howard
Published: July 2010

Hophornbeam copperleaf (Acalypha ostraefolia Ridd), an increasing weed problem in peanuts (Arachis hypogaea L.) in the southwestern United States, is resistant to most presently used herbicides. Research was conducted to design and evaluate production systems that would provide full season control of this weed in peanuts. Screening experiments indicated several herbicides would control copperleaf but that they were not selective for peanuts. Preliminary systems utilizing alachlor (2‐chloro‐2',6'‐diethyl‐N‐(methoxymethyl)acetanilide) at 2.24 kg/ha combined with rotary cultivation provided early but not full season control. Ultimately systems involving a preplant herbicide, alachlor or fluorodifen (p‐nitrophenyl α,α,α‐trifluoro 2‐nitro‐p‐totyl ether) either preemergence or with several postemergence combinations, and timely cultivations were developed that controlled copperleaf for the entire growing season. Fluorodifen combinations (at 5 kg/ha) applied postemergence to peanuts and copperleaf up to 7.5 cm tall provided excellent weed control with no visible crop injury.
Elbon Rye as Quality Forage to Ozark Deer during Winter1
Authors: Short Henry L. , Segelquist Charles A.
Published: July 2010

Suitable foods for deer (Odocoileus virginianus Zimmermann) in the Ozarks are deficient in quality and quantity during winters when oak mast crops are poor. Elbon rye (Secule cereale L.) forage improves deer carrying capacity during these times. To evaluate its quality for deer, we examined the digestibility and nutrient composition of elbon rye at successive stages of plant development. Rate of digestion and maximum digestibility, as measured by the nylon bag technique using ruminally cannulated goats, diminished as elbon rye matured. The time required for maximum digestion to occur increased from 48 hours for immature elbon rye harvested during February to 168 hours for mature rye harvested in May and June. Elbon rye yielded up to 1,450 kg/ha dry weight, was heavily utilized by deer, and was most nutritious during vegetative stages in mid to late Winter.
Modeling Dry Matter Accumulation in Dryland Winter Wheat1
Authors: Rickman R. W. , Ramig R. E. , Allmaras R. R.
Published: July 2010

A deterministic model of dryland winter wheat [Triticum aestivum ssp. vulgare (Vill., Host) ‘Nugaines’) growth in the Pacific Northwest was developed and field tested to more adequately quantify the influences of tillage induced microclimatic changes on wheat production. Daily dry matter accumulation of winter wheat is described by a modification of the Blackman compound interest formula. Daily environmental variables (soil water supply, N supply, soil and air temperature, relative humidity, wind, rainfall, and solar radiation) are used in the two‐component model. For inputs, initial conditions are needed which describe the field location (soil depth, water supply, fertilizer added, crop dry matter present, growth constants for the wheat variety, maximum rooting depth, and average temperature for the last 3 days). Dry matter production and the water budget are determined daily, until the water supply is exhausted or the crop is mature.

Field tests of the model indicated accurate prediction of the effects of water and N supply and surface mulch for the first half of the growing season. After flowering, the observed dry matter accumulation was greater than projected by the water response function of the model. Much greater water use efficiency (daily increase in dry matter/ daily water transpired) occurred after flowering. This may be partially attributable to upward water flow from below 240 cm, which was not included in the measured available water. To improve growth prediction by the model, accurate measurement of the available water supply and alteration of the late season water response function are needed.
Hybrid Grain Sorghum Response to Magnesium Fertilization1
Authors: Gallaher R. N. , Harris H. B. , Anderson O. E. , Dobson J. W.
Published: July 2010

Limited information is available on Mg requirements for grain sorghum (Sorghum bicolor [L.] Moench). This experiment was performed to evaluate hybrid response in yield and Mg concentration in leaf tissue from varying levels of Mg. Three grain sorghum hybrids were grown for 3 years at five rates of Mg fertilization on a Tipic Udifluvent (sandy loam) low in available Mg. Residual soil Mg from application of fertilizer Mg increased with each increment of added fertilizer Mg. Leaf Mg ranged from 0.06% on check plots to 0.22% at the highest Mg fertilizer rate (68 kg/ha). Hybrids responded in yield and Mg concentration in the leaf to Mg fertilization. A quadratic regression model was fitted to yield and Mg concentrations in the leaf tissue. The linear effects of time accounted for more yield differences than any other variable while fertilizer Mg accounted for more differences in Mg concentration in the leaf. The magnitude of the partial regression coefficients show that 2.21 kg fertilizer Mg/ha is required to give the same increase in yield as 1 kg soil Mg/ha. Indications were that the relative response in leaf Mg concentrations to a given increment of fertilizer Mg would change inversely with soil test Mg levels. The time and method of applying fertilizer Mg might have been a factor in its availability to plants in that the level of residual Mg increased from year to year.
Yield Response of Alfalfa Cultivars and Clones to Several pH Levels in Tatum Subsoil1
Authors: Buss G. R. , Lutz J. A. , Hawkins G. W.
Published: July 2010

Breeding for increased tolerance to high aluminum‐low pH soils should enlarge the range of adaptation of alfalfa (Medicago sativa). This research was undertaken to obtain information on the range of genetic variation present in alfalfa cultivars for reaction to soil pH in a high aluminum soil.

Eighteen alfalfa cultivars were planted in unlimed (pH 4.4) and limed (pH 6.0) Tatum (Typic Hapludults, clayey, mixed, thermic) subsoil. None survived in the unlimed soil and all grew in the limed soil. Clones were selected for root development in unlimed soil after growing down through a 5 cm layer of limed soil. When grown at pH levels of 5.3, 6.1, and 7.5, they showed a highly significant clone × pH interaction for yield. However, on the average they did not seem much more acid tolerant than unselected clones. This screening technique was somewhat successful in isolating acid tolerant clones, but forage yield at low pH appeared to be a better criterion.

Our results indicate that alfalfa cultivars exhibit a narrower range of acid tolerance than is known to exist in several other crop species, but that individual clones differ in their reaction to both low and high soil pH. We concluded that sufficient genetic variation exists to permit selection for tolerance to low pH, but the narrow genetic base might limit progress. Also the overall adaptation of selected populations might be somewhat unpredictabe because of the clone × pH interaction.
Wheat Production Estimates Using Satellite Images1
Authors: Morain S. A. , Williams D. L.
Published: July 2010

Wheat (Triticum aestivum L.) area and production statistics, as derived from satellite image analysis, are presented for a 10—county area in southwest Kansas. The object of the study was to determine whether production statistics could be accurately estimated using Earth Resource Technology Satellite (ERTS) imagery. The procedure involved locating, identifying, and measuring the area of wheat fields on images obtained at several times in the growing cycle and combining these data with the estimated yield obtained from a preexisting yield model. The results (representing the 1972–73 crop year) are compared for accuracy against both the SRS August estimate and its final (official) tabulation. The area estimates from imagery for both dryland and irrigated winter wheat were within 5% of the official figures for the same area, but predated them by almost 1 year. Yield on dryland wheat was estimated by the Thompson weather model to within 0.1% of the observed yield. A combined irrigated and dryland wheat production estimate for the 10—county area was completed in July 1973 and was within 1% of the production reported by SRS in February 1974.
Effect of Simulated Plow‐sole on Water Uptake and Yield of Dryland Wheat1
Authors: Prihar S. S. , Singh Piara , Gajri P. R.
Published: July 2010

Yield of dryland crops grown on stored water is determined by water use from the profile which, in turn, is related to the extent of root proliferation in different layers. Plow‐soles of high strength may retard root growth and adversely affect crop production. We determined the effect of initial profile water storage and soil compaction below the seed on the growth and the yield of dryland wheat, (Triticum aestivum L.) in field experiments during 1970–71 and 1971–72. Compaction reduced water use from deeper layers and decreased grain yield during both years. Evidently, it retarded root growth through increased soil strength. Compared with lower initial water storage, higher initial water storage in the profile resulted in more vigorous plants, deeper rooting, greater water use from lower soil layers and higher yields.

The results suggest that for greatest yields, compact layers below the seed must be loosened by tillage to permit deeper rooting. Also, in the absence of early season rain, a small supplementary irrigation to the young crop may stimulate deeper rooting and increase water use from lower layers.
Differential Response of Two Corn Inbreds to Varying Root Temperature1
Authors: Porter O. A. , Moraghan J. T.
Published: July 2010

Root temperature is a factor which greatly affects corn (Zea mays L.) growth. However, little information is available concerning the relative responses of different genotypes to changes in temperature. Two experiments were done to gather this information. The purpose of the first experiment was to compare the growth of 12 inbreds in nutrient solutions maintained at 14.8, 19.4, 23.9, and 28.2 C. Air temperature ranged from 23.9 to 32.2 C. Several lines developed an abnormality in growth that resembled Ca deficiency as the root temperature was increased. The ND33 line was most severely affected by root temperature. The abnormality developed first and was most severe at 28.2 C, was least severe at 19.4 C, and did not occur at 14.8 C. The ND203 line grew normally but its growth was greatly stimulated by increasing root temperature.

The objective of a second experiment was to learn the cause of the root‐temperature dependent abnormality. The ND33 and ND203 lines were grown in nutrient solutions maintained at 14.8 and 28.2 C. The ratios of top growth at 28.2 C to that at 14.8 C for ND203 and ND33 after 4 weeks were 7.8 and 1.7. Percentage Ca in the tips of the youngest three unfurled blades of both inbreds at 2 weeks was less at 28.2 C. The ND33 line contained lower concentrations of leaf‐tip Ca than ND203. In contrast, whole plant Ca percentage were larger at 28.2 C and ND33 contained higher concentrations than ND203.

We hypothesize that the rapidly growing, newly emerging leaves of ND33 were affected by Ca deficiency at the higher root temperature. The results suggest that attention should be paid to genotype when corn‐root temperature studies are being planned.
Effect of Nitrogen Fertilization on the Recovery of ‘Merion’ Kentucky Bluegrass from Scalping and Wilting1
Authors: Watschke T. L. , Waddington D. V.
Published: July 2010

This study was conducted on ‘Merion’ bluegrass (Poa pratensis L.) to determine the effect of different N sources, rates, and timing on the resistance to, and recovery from, wilting and scalping. In August 1972, sod plugs were taken from field plots fertilized at different rates and application dates with urea, Uramite (38‐0‐0, ureaform), Milorganite (6‐1.3‐0, activated sewage sludge), isobutylidene diurea (30‐0‐0; IBDU), Urex (29‐0‐0, extruded urea‐paraffin matrix), and 18‐6‐12 (with twothirds of the N from ureaform), and a check plot. Plugs were placed in an unshaded greenhouse for several simultaneously conducted experiments.

One set of plugs was allowed to wilt. Turf fertilized at the highest N rate tended to wilt quickest, while the unfertilized check was most resistant to wilting. After watering, turf that was slowest to wilt, recovered quickest. Another set of plugs was allowed to grow 9 weeks, after which length, width, green and dry weight, and percent moisture of leaves were measured. The grass was scalped to 1.3 cm and data on regrowth were collected. Plants fertilized at the highest N rates recovered faster, had greater clipping weights, longer and wider leaves, and higher percent moisture than those lightly fertilized. Plants treated with a low rate of Uramite, however, recovered rapidly indicating release of residual N from prior seasons. Total nonstructural carbohydrates were lower for fertilized than unfertilized turf, and changes in carbohydrates with time were influenced by the N treatment. In general, as N rates increased, plants wilted quicker and recovered slower; recovery from scalping was improved; and carbohydrates decreased.
Thatch Development and Other Effects of Preemergence Herbicides in Kentucky Bluegrass Turf1
Authors: Turgeon A. J. , Freeborg R. P. , Bruce W. N.
Published: July 2010

Preemergence herbicides have been used extensively on turf in recent years to prevent annual weed development. Applications of these herbicides have been suspected of causing reduced turfgrass quality. The purpose of this study was to determine whether repeated use of preemergence herbicides resulted in thatch development and other effects associated with turfgrass deterioration.

Six preemergence herbicides were applied annually for 4 years to ‘Kenblue’‐type Kentucky bluegrass (Poa pratensis L.) growing on an Aquic Argiudoll (Flanagan silt loam). Calcium arsenate and bandane (polychlorodicyclopentadiene) applications were associated with increased leaf spot (Helminthosporium vagans Drechel.) disease, higher wilting tendency, reduced shoot and root growth, and substantial thatch development. The thatching tendency was associated with a complete lack of earthworm (Lumbricus terrestris Linn.) activity in the underlying soil. Bandane residue was largely confined to thatch while calcium arsenate was more generally distributed throughout the upper thatch‐soil profile. Verdure was significantly reduced in plots treated with bensulide [0,0‐diisopropyl phosphorodithioate S‐ester with N‐(2‐mercaptoethyl)benzenesulfonamide] while benefin (N‐butyl‐N‐ethyl‐α,α,α,‐trifluro‐2,6‐dinitro‐p‐toluidine) D C P A (dimethyl tetrachloroterephthalate) and siduron [l‐(2‐methylcyclohexyl)‐3‐phenylurea] treatments, produced no measurable effects.
Effects of Boron Accumulation in Soybean Seed on Several Characteristics of Germinated Seedlings1
Authors: Touchton J. T. , Boswell F. C.
Published: July 2010

The range from deficiencies to toxicities for micronutrients in plant growth is often small. Content in seed could possibly influence germination and seedling growth, especially for boron.

A greenhouse study was initiated to determine the effects of B accumulation in soybean [Glycine max (L.)] seed on germination quality. Seeds were selected from field grown parent plants that had been fertilized with broadcast and foliar applications of B at rates of 0.00, 0.28, 0.56, 1.12, and 2.24 kg/ha. Germination percentage, average dry weight per seedling, and tissue concentrations of P, K, Ca, Mg, Mn, Fe, Cu, Zn, AI, Mo, Sr, Ba, and Na were not affected by method or rate of B applied to the parent plant. The differential B accumulation in the seeds from the original B applications to the parent plants resulted in significant differences in B accumulations in the germinated seedlings.
Perennial Irrigated Pastures. II. Average Daily Gain and Carcass Characteristics of Yearling Beef Steers on Irrigated Pasture Supplemented by Alfalfa Cubes1
Authors: Raguse C. A. , Hull J. L. , Henderson D. W. , Osman A.
Published: July 2010

Recent high grain prices and other factors have led to a resurgence of interest in greater use of forages in beef production. An experiment was designed to test the effects of combinations of perennial irrigated pasture and alfalfa cubes on gains and carcass characteristics of yearling beef steers. The treatments consisted of irrigated pasture only, three combinations of irrigated pasture supplemented by increasing amounts of alfalfa (Medicago sativa L.) cubes, and a fifth treatment consisting of alfalfa cubes only. The pastures were 6‐year‐old stands of 55% orchardgrass (Dactylis glomerata L.), 25% strawberry clover (Trifolium fragiferum L.), 15% perennial ryegrass (Lolium perenne L.), and 5% Ladino clover (T. repens L.), providing a seasonal average grass: legume ratio of 70:30. The soil was the Yolo series of a finesilty, mixed, nonacid, thermic, typic xerorthent entisol. Stocking rates were 7.7, 9.4, 11.6, and 15.5 animals per ha, respectively, for the above treatments during a 200‐day grating season. Average daily cube intake per animal for the five treatments ranged from zero through 1.7, 2.7, 4.3 and 9.9 kg, respectively.

Average daily gain, daily energy gain, and body weight gain for the irrigated pasture‐only and all pasture‐cube combinations were significantly different from the cubesonly treatment, but not from each other. Measurements of botanical composition and plant heights indicated that the various stocking rates imposed moderate and similar grazing pressures throughout the season.

The carcass characteristics of percent protein, fat, and water were statistically the same for all cube‐pasture combinations, as was energy/kg gain.

Because of the absence of statistical significance (0.01 level) for differences in weight gain, energy gain, and carcass characteristics for the pasture‐cube treatments, it was concluded that they were equal in relation to beef production and market quality. These management combinations, over the range studied, are therefore biologically sound and their acceptance would depend on economic and/or other factors.
Palatability of Leaves of Tall Fescue and Reed Canarygrass and of Some of Their Alkaloids to Meadow Voles1
Authors: Kendall W. A. , Sherwood R. T.
Published: July 2010

The objective of these experiments was to evaluate use of meadow voles (Microtus pennsylvanicus) in a bioassay for estimating palatability of forages and some forage constituents to large animals. A small animal bioassay would enhance studies of factors affecting forage palatability and effects of palatability on animal intake. Meadow voles were provided a standard diet ad libitum and a choice of the standard diet or an experimental diet for three 30‐min periods each day. Intakes of the experimental rations were used as an index to palatability.

Palatability of fresh leaves of 14 clones of reed canary‐grass (Phalaris arundinacea L.) was negatively correlated with their total alkaloid level, in agreement with published responses of large animals. Mixtures of 0.5% gramine; 5‐MeO‐N, N‐dimethyltryptamine; N, N‐dimethyl‐tryptamine; 5‐methoxytryptamine‐HCI, or N‐monomethyl‐tryptamine with the starch made the rations unpalatable. This provided direct evidence for unpalatability of the tryptamine alkaloids of reed canarygrass.

The meadow voles did not discriminate between ‘Kentucky 31,’ ‘Kenwell,’ and ‘Kenhy’ tall fescue (Festuca arundinacea Schreb.) when fed fresh leaves. Sheep grazed on the same material preferred Kenhy and rejected Kentucky 31. Palatability to meadow voles of fresh and dried leaves of Lolium ✕Festuca hybrid derivatives or Festuca cultivars was not related to perloline concentration. The bioassay was not suitable for detecting the unknown factor(s) affecting palatability of fescue to sheep.
Nitrogen Transformations in Soil as Affected by the Fungicides Benomyl, Dyrene, and Maneb1
Authors: Mazur A. R. , Hughes T. D.
Published: July 2010

The frequency and extent of fungicide use on putting green turfgrasses prompted investigations to determine the effect of three commonly used fungicides on N transformations in soil. Laboratory and field studies were conducted to study the effect of the following fungicides on nitrification and N mineralization in soil: benomyl [(methyl l‐(butylcarbamoyl)‐2‐benzimidazolecarbamate)], rene [(2,4‐dichloro‐6‐(0‐chloranilino)‐s‐triazine)], and rnaM‐7 neb (manganese ethylenebisdithiocarbamate). In laboratory studies, the three fungicides were added at rates of 0, 25, 75, and 150 ppm and the soil incubated at 21±1 C and moisture content of 30±1%. Analyses for NH+4‐N and (NO‐2 + NO‐3)‐N were conducted at various times during a 16‐week incubation period. Almost no effect was detected for benomyl, but a complete blockage occurred at the 150 ppm rate of maneb. Dyrene had an intermediate effect. Based on concentrations of (NH+,4 + NO‐2 + NO‐3)‐N in the untreated control as compared to treated soil, benomyl was stimulatory to N mineralization. Inhibitory effects were observed for both Dyrene and maneb after 4 weeks of incubation, but these effects had disappeared after 16 weeks.

In the field, 14 weekly applications of benomyl, Dyrene, and maneb at 90, 90, and 135 g active ingredient/are were made to a ‘Penncross’ creeping bentgrass, Agrostis palustris Huds., golf green. Soil samples were taken from a depth of 0 to 2.5 cm (excluding thatch) and determinations of NH+4‐N and (NO‐2 + NO3‐)‐N concentrations were made at weekly intervals during a 5‐week incubation. There was no effect of any of the fungicides on nitrification but enhanced N mineralization occurred with application of all three of the fungicides.

The differences in the effects of these fungicides on nitrification and N mineralization in laboratory as compared to field applications were considered to be the result of lower rates of application associated with more rapid rates of degradation under field conditions as contrasted with the high single rates of application under laboratory conditions.
Nodulation Responses from Nitrogen Applied to Soybean Half‐Root Systems1
Authors: Hinson Kuell
Published: July 2010

Interrelationships between combined and symbiotic N in soybeans (Glycine max L. Merr.) are complex. To further clarify the potential role of combined N in field production, we tested the hypothesis that adding N to one‐half of a soybean root system would have no effect on nodule formation or nodule growth on untreated roots of the same plant. Roots of greenhouse plants were divided into two equal parts and transplanted into different pots of low‐N field soil when plants were 17 days old. Half of the root system received no nitrogen (—N), and the other (+N) received 0, 30, 60 or 120 ppm in Experiment I and 0, 15, 30, 60, 120 or 240 ppm N in Experiment II. Nitrogen reduced nodule number and weight in +N pots. In —N pots nodule numbers were nearly constant, but nodule weights differed significantly at the end of each experiment (44 and 57 days from planting, respectively). On half‐root systems whose companion roots received intermediate rates of N, nodule weights in —N pots were up to 50% more than those for controls (neither half received N) in each experiment. However, for the highest rate of N in each experiment, nodule weights in —N pots were equal to or significantly lower than those from control pots. In —N pots of the 240 ppm treatment in Experiment II, nodule weights were 40% less than for controls. This is interpreted as a nonlocalized inhibition of nodule development. Nitrogen increased root weight in +N pots in both experiments, but increased root weight in —N pots only in the longerduration Experiment II. Nitrogen also increased total plant weight, but N added to similar soil in a field experiment did not increase seed yield. In another field experiment, side‐dressing one vs. both sides of field‐plot rows with N did not influence seed yield and had no detectable effect on localizing nodule development. Thus, responses to N by greenhouse seedlings were not transferred to seed‐yield differences in field plots.
Reflectant Induced Modification of Soybean Canopy Radiation Balance. III. A Comparison of the Effectiveness of Celite and Kaolinite Reflectants1
Authors: Lemeur Raoul , Rosenberg Norman J.
Published: July 2010

Soybeans (Glycine max L. ‘Amsoy’) were coated with Celite and kaolinite reflectants to increase reflection and reduce net radiation. Such treatment is intended to decrease evapotranspiration and improve water use efficiency. The study was undertaken to establish the specific reflection patterns at various wavelengths of reflectorized soybeans. The effectiveness of the materials and the influence of additional applications applied factorially during the growing season was also evaluated. Both reflectant materials are most effective in the waveband of photosynthetically active radiation (PAR: 400–700 nm). Reflection coefficients in this waveband were double that from a natural canopy. The effect on near infrared radiation (NIR: 750–1,550 nm) was small. The average increase in shortwave reflection (300–3,000 nm) ranged from 10 to 20%. Reduction of net radiation measured over the treated canopies ranged from 5 to 10%. Within the treated canopies net radiation was greater than in the untreated crop. Application of reflectants at the beginning of the growing season was more effective in increasing reflection and reducing net radiation than were applications at later stages of crop maturity. The effects of additional treatments as the crop developed were not cumulative. Therefore additional applications should be made only to maintain the quality of the coating. Celite is the more effective material, producing the same degree of reflection with half as much material as is required when kaolinite is used.