bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response of Wheat to Irrigation in a Tropical Soil1
Authors: Ghuman B. S. , Maurya P. R. 
Published: July 2010

AbstractSubstantial hectarages of land are planted to wheat (Triticum aestivum L.) every year in northern Nigeria. However, information on scheduling of irrigation for wheat grown in this part of the world is scanty. Field experiments were, therefore, conducted from 1982 to 1984 to study the response of wheat to seasonal and individual irrigations. There were three seasonal irrigations: (i) 300 mm, (ii) 450 mm, and (iii) 600 mm. Each seasonal irrigation was divided into three smaller individual irrigations (30,45, and 60 mm), which were applied at different frequencies. The experimental field soil has a water table that fluctuated between 85‐ and 115‐cm depths during the 1982–1983 and 1983–1984 growing seasons. Dry matter accumulation, plant height, and grain and straw yields were not significantly affected by the depth of seasonal irrigation. However, application of 30 and 45 mm water per irrigation gave higher grain yields than 60 mm. Wheat produced 5 to 6 Mg ha−1 grain when irrigated with 30 mm of irrigation water at 7‐day intervals.
Normal‐12 and Brown Midrib‐12 Sorghum. II. Chemical Variations and Digestibility1
Authors: Akin D. E. , Hanna W. W. , Snook M. E. , Himmelsbach D. S. , Barton F. E. , Windham W. R. 
Published: July 2010

AbstractMarginally digested tissues in the brown midrib‐12 (bmr) sorghum (Sorghum bicolor (L.) Moench.) mutant are more readily degraded than similar tissues in the normal (N) line. Reduced lignin concentrations have been reported to be a factor affecting digestibility of bmr genotypes, but lignin type could also influence digestibility. The objectives of this work were to (i) examine N‐12 and bmr‐12 plants for variations in chemical composition, including phenolic acids and phenolic structure, using solid‐state nuclear magnetic resonance (NMR) spectroscopy; and (ii) evaluate by microscopy the effect of permanganate delignification. Leaf blades of bmr plants were significantly (Ρ ≤ 0.05) lower in neutral detergent fiber (NDF) and permanganate lignin (PML), and higher in in vitro dry matter digestibility; leaf sheaths contained significantly less PML. Solid‐state NMR spectroscopy suggested that bmr leaf blades had lower amounts of bound syringyl moieties. The predominant alkali‐soluble (1.0 M NaOH) phenolic acids in both plant types were ρ‐coumaric and ferulic acids, and ρ‐coumaric acid was significantly lower (Ρ ≤ 0.05) in concentration in bmr leaves. Treatment of intact blade sections with permanganate to oxidize lignin compounds resulted in a reduced staining intensity for lignin identified by both the acid phloroglucinol and chlorine‐sulfite tests in all but midrib sclerenchyma; lignin staining intensity did not differ between plant types. Degradation of delignified midribs by rumen microbes indicated that the tissues were more degradable in bmr than in N plant types. Results suggest that reduced concentrations of phenolic acids (especially ρ‐coumaric acid) and reduced levels of etherated syringyl moieties in conjunction with reduced concentrations of lignin are factors in the improved quality of bmr‐12 sorghum.
Evaluation of Corn Growth and Productivity with Three Conservation Tillage Systems1
Authors: Al‐Darby A. M. , Lowery B. 
Published: July 2010

AbstractThis study was conducted to provide needed data comparing corn (Zea mays L.) growth and productivity for several conservation tillage (CT) systems. Such data will provide necessary information to better evaluate the economical potential of CT systems in the Northern Corn Belt. The tillage systems used in this study were till‐plant (TP), chisel (CH), no‐till (NT), and conventional (CN) tillage. The study was conducted on a Griswold silt loam soil (fine‐loam, mixed, mesic Typic Argiudoll) at Arlington, WI, and a Plainfield loamy sand soil (sandy, mixed, mesic Typic Udipsamment) at Hancock, WI, over a 3‐yr period. Final plant emergence and growth and yield parameters were measured. The final plant emergence was higher with the CT systems compared to CN at Arlington, while the final plant emergence of the NT system was lower than other tillage systems at Hancock. Plant height, leaf area, and dry matter per plant early in the growing season, for both locations ranked: CN > TP ≷ CH > NT, and in most cases were significantly different. However, at the end of the growing season, these growth parameters were not significantly different. Days from planting to 50% silking for the NT system were significantly delayed by 2 to 3 and 4 days at Arlington and Hancock, respectively. No‐till had the highest grain moisture content. Grain yields with CT systems were equal to or greater than CN tillage at both locations. No‐till grain yield at Hancock was 18% greater than CN when rainfall was below normal in 1983. Three‐year grain yield averages for the silt loam soil were 8.75,8.78,8.97, and 8.49 Mg ha 1 for CN, TP, CH, and NT, respectively. Three‐year grain yield averages for the loamy sand soil were 6.48, 6.48, 6.44, and 6.79 Mg ha 1 for CN, TP, CH, and NT, respectively. The results from this study showed no serious growth and yield reductions with CT systems compared to CN tillage in the Northern Corn Belt.
Forage Quality of Selected Wild Sunflower Species1
Authors: Seiler Gerald J. 
Published: July 2010

AbstractAlthough wild sunflower (Helianthus spp.) may be components of pastures, hay, and silage, little information exists on their contribution to overall forage quality. The objective of this study was to evaluate 26 taxa of wild sunflower species for protein and mineral concentrations at various stages of maturity. The field experiment was conducted on Pullman clay loam (fine, mixed, thermic Torrertic Paleustoll) soil, and the experimental design was completely randomized with three replicates. The leaves and stems of 19 annual and seven perennial taxa of wild species and a commercial sunflower, ‘hybrid 894’, were planted in pure stands and evaluated at vegetative, flowering, and fruiting stages to ascertain their nutritive value for ruminants. Crude protein (CP) of 140 g kg−1 and above occurred in leaves of 19 of 26 taxa (15 were annuals) at the vegetative stage. Nutritionally adequate amounts of Ca (2 to 5 g kg−1) were present in the leaves and stems of all wild sunflower taxa. Nutritionally adequate amounts of Mg (2 g kg−1) and K (8 g kg−1) were present in the leaves of most wild taxa at all stages of maturity. Leaves and stems of most taxa at the flowering and fruiting stages had sub‐optimum P (< 3 g kg 1) levels for high producing ruminants. Nutritionally adequate amounts of CP, Mg, and P were present in whole seeds of most species. At varying maturity stages, nutrient levels of some of the wild sunflower species are comparable to that of cultivated sunflower. Ruminants most likely would not graze pure stands of wild sunflower but would graze in mixed stands with other forbs and grasses. Hence, wild sunflower may be incorporated into hay or silage and provide a satisfactory nutrition level for ruminants.
Growth of Creeping Bentgrass on a New Medium for Turfgrass Growth: Clinoptilolite Zeolite‐Amended Sand1
Authors: Ferguson G. A. , Pepper I. L. , Kneebone W. R. 
Published: July 2010

AbstractClinoptilolite zeolite (Z) is a natural silicate mineral with a three‐dimensional lattice, a high degree of internal tunneling, and a large cation exchange capacity and water holding capacity even when particles are sand‐sized (> 0.5 mm). The hypothesis of this study was that clinoptilolite had the facility to preferentially and internally sorb NH+4 where it would be physically protected from microbial nitrification resulting in increased plant fertilizer‐N use efficiency. A field study relating growth and quality of creeping bentgrass (Agrostis palustris Huds.) to ranges of Z amendment of sand and N application rates of 25, 50, or 75 kg ha 1, was initiated at the University of Arizona, Turfgrass Research Center in the spring of 1981. Germination and establishment were significantly increased by amendment of sand with 5 or 10% Z. Bentgrass quality in August 1981 was significantly increased by the 5% Z treatment. The 10% Z treatment initially did not increase turf quality due to the initial high Na content of the Z. However, by January 1982 both Z treatments gave significantly increased turf quality. At this time, excess N reduced turf quality due to high N‐induced iron chlorosis. Clipping yields from seven harvests and N‐use efficiency increased significantly with Z. Zeolite also increased both root growth as indicated by soil organic carbon and shoot‐clipping P content. Excess N decreased root growth. Phosphorus uptake decreased with N during the hot summer months but increased when temperatures were cool. These data indicate that Z has potential as a new medium for the growth of turfgrass.
Application of GOSSYM to Yield Decline in Cotton. I. Systems Analysis of Effects of Herbicides on Growth, Development, and Yield1
Authors: Reddy V. R. , Baker D. N. , Whisler F. D. , Fye R. E. 
Published: July 2010

AbstractCotton (Gossypium hirsutum L.) yields have declined since 1965 despite improvements in technology and introductions of higher yielding cultivars. Cotton scientists have been unable to identify exact causes of the yield decline. One suggested cause is the increased use of herbicides and their toxic effects on root growth in the herbicide incorporated zone. In this study, the computerized crop simulation model, GOSSYM, was used to predict cotton performance under several levels of herbicide‐induced root reduction under various environmental conditions in a Leeper clay loam soil (fine, montmorillonitic, nonacid, thermic Vertic Haplaquept). The model predicted a small increase in yield when root reduction was moderate and at shallow depths. However, when the depth of root reduction increased to 200 mm or the percentage of root reduction increased, there was a predicted decrease of up to 40% in cotton lint yield. This decrease in lint yield was much larger when decreased root length was combined with reduced soil water permeability in remaining roots. Predicted yield was also reduced under unfavorable weather conditions. With increase in the depth of root reduction or increase in the percentage of root reduction and with permeability reduction there was a decrease in the root growth throughout the season. Increased N and water shortages were apparent with increase in the depth or level of root reduction. It was concluded that improper application of herbicides was one of the contributing factors for the cotton yield decline.
Response of Susceptible and Resistant Alfalfa Cultivars to Phytophthora Root Rot in the Absence of Measurable Flooding Damage1
Authors: Mueller S. C. , Fick Gary W. 
Published: July 2010

AbstractAlfalfa (Medicago sativa L.) growth and development is known to be adversely affected by Phytophthora megasperma Drechs. f. sp. medicaginis (Pmm), a root rotting fungus most active under waterlogged soil conditions. The response of the plant to the pathogen under low levels of flooding stress is not well‐established, but that relationship is important during alfalfa establishment on soils flooded for short periods by rainfall. Our main objective was to determine if yield reductions caused by the disease occurred in the absence of yield reductions caused by flooding on seedling alfalfa plants. Controlled environment studies were conducted to quantify the effects of flooding or inoculation with Pmm, or both, on alfalfa yield and disease severity, and to examine the differential response of a susceptible (‘Iroquois’) and a resistant (‘Oneida’) cultivar. At 26°C, one or two 3‐day cycles of flooding with subsequent 4‐day drainage periods did not reduce dry matter yields of alfalfa shoots grown in either soil (mixed, mesic Typic Udipsamment) or vermiculite. Inoculation with Pmm significantly reduced the shoot yield of Iroquois, but not that of Oneida. The presence of an interaction between Pmm inoculation and cultivar in the absence of a flooding × cultivar interaction indicates true disease resistance and not simply increased flooding tolerance in Oneida. Oneida also showed fewer and less severe root lesions than Iroquois. Flooding increased both the incidence and severity of root lesions. The pathogen, Pmm, could be reisolated from root tissue in which disease symptoms were observed. Redox potentials indicated that anaerobic conditions developed quickly in both soil and vermiculite following flooding and that aerobic conditions were reestablished within one day in both media upon draining. Resistance to Phytophthora root rot is of value on new stands subjected to marginal flooding stress.
Relative Sensitivity of Nitrogen and Biomass Accumulation to Drought in Field‐Grown Soybean1
Authors: Sinclair T. R. , Muchow R. C. , Bennett J. M. , Hammond L. C. 
Published: July 2010

AbstractEvidence of differential sensitivity to drought between symbiotic N fixation and leaf photosynthesis in legumes has been measured under greenhouse conditions. If the greater sensitivity of N accumulation to drought is substantiated under field conditions, then important questions concerning legume production under water‐limited conditions must be considered. Consequently, the relative sensitivity of N and biomass accumulation to drought was examined in a 2‐yr study on ‘Biloxi’ soybean [Glycine max (L.) Merr.] grown in the field on Arredondo fine sand soil (loamy, siliceous, hyperthermic Grossarenic Paleudults). Various irrigation treatments were imposed during vegetative growth after canopy closure when solar radiation was almost fully intercepted. Shoot and root plus nodule biomass and N accumulation were determined from periodic harvests. Solar radiation use‐efficiencies were computed from regressions of biomass against cumulative solar radiation, and were found to range from 0.53 g MJ−1 under daily irrigation, to 0.23 g MJ−1 under the most severe drought treatment. Nitrogen accumulation rates were computed by regression of N accumulation against time, and were found to decline from 0.31 g N m−2 day−1 for the daily irrigation to 0.003 g N m−2 day−1 for the most severe drought treatment. In both years and all three drought treatments, the N accumulation rate was decreased relatively more than the solar radiation use‐efficiency for biomass accumulation. These results indicate that a high sensitivity of N accumulation to soil dehydration may be an important constraint on soybean productivity.
Comparison of Microscopic and Pinitol Techniques in Determining Legume Composition of Steer Diets1
Authors: Forwood J. R. , Stypinski P. , Mawhinney T. , Paterson J. A. 
Published: July 2010

AbstractKnowledge of botanical and chemical composition of herbage consumed by grazing livestock is essential in understanding animal performance and improving pasture and animal management. Esophageal fistula samples are considered to best represent cattle (Bos spp.) diets, but current microscopic methods used to determine botanical composition are time consuming, expensive, and may be subject to large operator error. Pinitol (1‐D‐3‐O‐methyl‐chiro‐inositol) has been found unique to the leguminosae family and accurate in determining alfalfa (Medicago sativa L.) percentage in greenhousegrown alfalfa‐tall fescue (Festuca arundinacea Schreb.) mixtures (R2 = 0.99). Its utility in estimating the legume composition of esophageally collected grass‐legume samples was compared to that of two widely used microscopic techniques. No significant differences were found between microscopic methods in pasture or hay aftermath of any treatments or dates. Sensitivity analysis showed no differences in the two methods related to their ability to detect dietary legume concentration changes in esophageal samples. Pinitol estimates of legume content were less (P<0.05) than those from microscopic estimates taken from orchardgrass (Dactylis glomerata L.) + legume [red clover (Trifolium pratense L..), birdsfoot trefoil (Lotus sp.), or alfalfa] pasture and hay aftermath, but not from nearly pure orchardgrass. The three methods provided similar estimates late in the grazing season when all values were low. With few exceptions the pinitol method underestimated legume composition of esophageal samples. In a separate experiment, the pinitol content of alfalfa, red clover, and birdsfoot trefoil extrusa after mastication and salivation was lower than that of unfed samples, suggesting that leaching may have been partially responsible for low estimates of legume composition by the pinitol method
A Leaf Area Index Model for Corn with Moisture Stress Reductions1
Authors: Flesch T. K. , Dale R. F. 
Published: July 2010

AbstractThe leaf area index (LAI) of a crop is an input in many agronomic models, but is time consuming to measure. An accurate method of estimating LAI is needed. Using measurements from 72 plots over 17 yr, a model was developed to predict corn (Zea mays L.) LAI based on a normalized thermal crop calendar (NC). The seasonal change in LAI was divided into three periods: 1) planting to silking; 2) silking to the start of rapid senescence; and 3) rapid senescence. The LAI data during the first period were fitted with a logistic function of NC and the maximum leaf area per plant (LAmax) using plot‐years with no moisture stress. The LAmax was predicted using the population density and a hybrid coefficient. The decline in LAI during the second period was predicted with NC, the maximum LAI, and a hybrid coefficient. During the third period, LAI prediction was based on the number of days past the beginning of rapid senescence. Leaf area measurements in plot‐years with moisture stress were used to develop a stress growth factor (SGF) to reduce the growth of LAI in the first period. The SGF was determined from the daily ratios of actual to potential evapotranspiration (ET/PET). Daily ET/PET values < 1.00 reduced LAI growth. Moisture stress did not affect LAI during Periods 2 and 3. The error of predicted LAI for independent plot‐years averaged 19% for the first period, 11% for the second, and 58% for the period of rapid senescence. The model is recommended for broader testing and use.
Planting Date, Row Spacing, and Irrigation Effects on Soybean Grown on Clay Soil
Authors: Heatherly L. G. 
Published: July 2010

AbstractBecause of adverse weather and management decisions, soybean [Glycine max (L.) Merr.] is often planted beyond the period considered optimum. In the southern Mississippi River alluvial plain, this frequently occurs on clay soil. Research was conducted from 1984 through 1986 at Stoneville, MS, on Sharkey clay (very‐fine, montmorillonitic, nonacid, thermic Vertic Haplaquept) to determine the effect of irrigation and row spacing on seed yield and yield components of early or mid‐May versus late‐June plantings of soybean. ‘Braxton’ was planted in 0.53‐ and 1.02‐m‐wide rows and was either nonirrigated or irrigated from the R1 to R6 stages. Irrigation significantly increased yield regardless of row spacing or planting date, but the increase was always greater for early plantings. Seed yields from the irrigated early plantings in 1984,1985, and 1986 averaged 3570, 2960, and 2695 kg ha−1, while the later plantings averaged 3115,1900, and 1425 kg ha−1, respectively. Without irrigation, yield differences between planting dates were not significant. Average nonirrigated yields were 1495,1760, and 185 kg ha−1 for 1984,1985, and 1986, respectively. Narrow rows produced 100 kg ha−1 more seed when averaged over all environments, and row spacing did not significantly alter the planting date × irrigation treatment interaction. Yield increases from irrigation were primarily attributable to increased number of seed. These results show that (i) late planting of soybean on clay soil in either row spacing used will result in significant yield decline even with irrigation, (ii) nonirrigated production of soybean on clay soil is risky, and (iii) choice of row spacing is not as important a consideration as is the alleviation of drought stress on this soil type regardless of planting date.
Supplemental Fertilization of Irrigated Corn Guided by Foliar Critical Nutrient Levels and Diagnosis and Recommendation Integrated System Norms
Authors: Elwali A. M. O. , Gascho G. J. 
Published: July 2010

AbstractApplying moderate amounts of fertilizers to irrigated corn (Zea mays L.), and making corrections during the growing season as indicated by foliar analysis, is very appealing as a means of reducing risk and increasing fertilizer efficiency, especially on irrigated sandy soils. This study was conducted to determine the relative abilities of the Diagnosis and Recommendation Integrated System (DRIS) and the Critical Nutrient Level (CNL) approach to predict supplemental fertilization needs of irrigated corn based on foliar analysis at the 10‐ or 12‐leaf stage. Three field experiments were conducted on a Bonifay sand (loamy, siliceous, thermic Grossarenic Plinthic Paleudult). Treatment variables in the first year consisted of a factorial combination of two basic N‐P‐K fertilization rates and four supplemental fertilizer treatments applied at the 12‐leaf stage using the DRIS and CNL approaches. In the second and third years, treatment variables consisted of four basic N‐P‐K fertilization levels and six supplemental treatments following foliar analysis at the 10‐leaf stage. Foliar analysis at the 10‐ or 12‐leaf stage was effective for making supplemental fertilizer recommendations for corn. Application of moderate amounts of fertilizers and supplemental applications during the growing season as indicated by both foliar CNL and DRIS norms significantly increased grain yield in two of three experiments. Both CNL and DRIS norms are needed for accurate interpretation of foliar values. Additional studies are needed to increase predictability of supplemental S and Mg applications.
Cotton Response to Planting Date and Mepiquat Chloride
Authors: Cathey George W. , Meredith William R. 
Published: July 2010

AbstractFew studies have documented the effect of planting date on cotton (Gossypium hirsutum L.) response to mepiquat chloride (MC) (N,N‐dimethylpiperidinum chloride). Planting dates were mid‐April, early May, and mid‐May during 1982, 1983, and 1984, and consisted of five cultivars representing three general maturity types: early—‘DES 422’; intermediate—‘Coker 3131’, ‘Stoneville 825’, and ‘McNair 235’; and full season—‘Deltapine 90’. Mepiquat chloride was applied at a rate of 49 g a.i. ha−1 when the plants had about 0.7 white flowers per meter of row. More parameters were affected by chemical treatment and planting date than by cultivars. Plants were taller and produced fewer flowers, smaller bolls, and less lint as planting dates were delayed. In addition, most boll components were adversely affected by delayed planting dates. However, most of the adverse effects caused by delayed planting were mitigated by the MC treatment. Mepiquat chloride x planting date interactions occurred for plant height, flower production, lint yield, and seed index. Mepiquat chloride caused a 4.5% reduction in lint yield from the early planted plots, and 5.4 and 12.7% yield increases from the optimum and late plantings, respectively. Mepiquat chloride increased boll weight in all plantings, but affected (increased) flower production only in the late planting. Seed index was increased and lint percentage reduced in all MC‐treated plots from each of the three plantings. The MC early, intermediate‐, and late‐planting plots averaged 0.11, 0.25, and 0.30 less height, respectively, than the control plots. Statistical significance was achieved only for the latter two plantings. These studies indicate that MC application would be most beneficial in late‐planted cotton, which tends to produce more vegetative growth than earlier plantings.