bluuebunny/crossref_metadata_2025_split huggingface dataset:
Irrigation Effects on Water Use, and Production of Tap Roots and Starch of Buffalo Gourd
Authors: Nelson J. M. , Scheerens J. C. , Bucks D. A. , Berry J. W. 
Published: July 2010

AbstractThe buffalo gourd (Cucurbita foetidissima HBK) is a possible new root starch crop for semiarid regions. Information on water use relationships of this species is needed to determine its suitability for arid lands agriculture. The objective of this study was to assess the influence of water management on buffalo gourd tap root production and water use. Five irrigation levels were evaluated for an annual buffalo gourd crop in 1985 and 1986 at a 360‐m elevation field site on Casa Grande sandy loam (fine‐loamy, mixed, hyperthermic Typic Natrargid) using plant populations of 400 000 to 450 000 plants ha−1. Irrigating at 50% available soil water (ASW) content (I1) gave higher fresh tap root yields than irrigating at 75% ASW (I2) (27.8 vs. 24.1 Mg ha−1) in 1985 with identical starch yields. In 1986 the I2 treatment was higher than the I1 treatment in starch yield (3.1 vs. 2.1 Mg ha−1) and tap root starch concentration (47.5 vs. 38.1%). Vines of water stressed plants (I2) grew rapidly when irrigated. Consumptive water use was 649 and 487 mm in I1 and I2, respectively. Peak consumptive use rates were <6.5 mm d−1. As much as 48% of seasonal water use was from the 0 to 0.4 m soil depth. Water was extracted to a depth of 2.6 m. The I2 treatment had the highest wateruse efficiency (WUE), 4.9 kg m−3, for fresh root production. The WUE for starch production was higher for the I2 treatment (0.62 kg m−3) than the I1 treatment (0.42 kg m−3). Irrigation scheduling to provide moderate stress reduces buffalo gourd water use without reducing starch yield, increasing its potential as a semiarid starch crop.
A Pinpunch Apparatus for Quantifying the Growth Rate Distribution in Monocot Leaves
Authors: Arkebauer T. J. , Norman J. M. 
Published: July 2010

AbstractThe expansion of monocot leaves in the field is needed to understand the effects of various treatments on plant growth. A pinpunch method (sample destructive) is described that measures the growth rate distribution of the leaf. This method uses a surplus chart recorder, a linear potentiometer, and a data logger. Three sources of error are described in detail and data is presented that compares relative growth rate of plants with differing total water potentials. The relative growth rate as a function of distance from the node of the expanding leaf, can be determined.
Root and Herbage Growth Response of Birdsfoot Trefoil Entries to Subsoil Acidity
Authors: Alison M. W. , Hoveland C. S. 
Published: July 2010

AbstractStand productivity and longevity of legumes are often limited by subsoil acidity in the highly weathered soils of the eastern USA. This study was conducted to determine differences among four birdsfoot trefoil (Lotus corniculatus L.) entries for tolerance to acid subsoil. The entries were grown in the greenhouse in 13 ✕ 60 cm polyethylene tubes containing a representative profile of Appling sandy loam (clayey, kaolinitic, thermic Typic Hapludult) soil. The surface soil (0 to 15 cm) was limed to pH > 6.0. The subsurface soil (15 to 60 cm) was either limed (pH > 6.0) or not limed (pH < 4.9). All entries had similar root length in the surface and subsurface soil when subsurface soil was limed. Root length of GA 1, ‘Norcen’, and ‘Fergus’ in unlimed subsurface soil was 93, 52, and 35%, respectively, of the ‘AU Dewey’ root length. Root length of AU Dewey in the surface soil was nearly twice as much when the subsurface soil was not limed as when it was limed. Root length of the other entries was similar in the surface soil, regardless of the subsurface soil treatment. Herbage yield of AU Dewey was similar on limed and nonlimed soils, while herbage growth by the other entries was less when the subsurface soil was not limed. Relative herbage yields of AU Dewey, Norcen, GA 1, and Fergus with acid subsurface soil were 100, 68, 64, and 24%, respectively. These differences show that birdsfoot trefoil cultivar selection in acid soil environments is important and that breeding for acid soil tolerance may be possible.
Vehicle‐Mounted Hydraulic Sampler for Urban Soils
Authors: Hipp Billy W. , Graff Paul S. 
Published: July 2010

AbstractSampling soils in landscapes and research plots in urban settings is normally done by hand because motorized samplers lack the mobility and small size. To facilitate sampling urban soils, a vehicle‐mounted hydraulic sampler was constructed by making minor modifications to commercially available equipment. The unit consists of a hydraulic sampler with self‐contained engine and hydraulic pump mounted on the back of a turf utility vehicle. Soil cores are taken with a 32 mm diam. ✕ 0.46 m long slotted tube. Samples can be taken to 1.2 m depth.
Nitrogen Distribution, Yield, and Quality of Silage Corn after Foliar Nitrogen Fertilization
Authors: Ippersiel D. , Alli I. , MacKenzie A. F. , Mehuys G. R. 
Published: July 2010

AbstractForage corn (Zea mays L.) is an important crop because of its high energy content; however, an improvement in the protein quality of forage corn would be desirable. In some instances foliar N fertilization has resulted in improved yield of corn. The objective of the study was to determine the effects of foliar applied N on yields and on forage protein quality. Foliar urea spray (20 kg urea N ha−1) was applied to DeKalb W‐844 corn at two growth stages: 10% silking and 4 wk after the 10% silking stage. The field experiment was carried out on a Ste‐Rosalie clay (very fine silty, mixed, non‐acid, mesic) and an Ormstown silty clay (fine silty, mixed, non‐acid,mesic), both Typic Humaquepts, in the 1984 and 1985 growing seasons. Applied urea Was not detectable on the leaf surface of the plants by the third day following spraying. A transitory increase in the urea‐N and nonprotein N contents was observed 1 d after the spray. By the third day following the spray, there was no difference in the urea‐N and nonprotein N contents of sprayed and non‐sprayed plants. The effects of the foliar sprays on whole‐plant yield, grain yield, and protein quality of corn silage were not consistent. In general, the second spray resulted in increased protein yields. The results suggest that, although the foliar‐applied urea was absorbed by the corn plants in all cases, its effect on yields and protein quality of the corn silage was variable.
Sprinkler Irrigation Effects on Determinate Soybean Yield and Lodging on a Clay Soil
Authors: Boquet D. J. 
Published: July 2010

AbstractDrought stress can reduce the yield of soybean [Glycine max (L.) Merr.] grown in the middle and lower Mississippi River Valley. A 3‐yr field study on Sharkey clay (very‐fine, montmorillonitic, nonacid, thermic Vertic Haplaquept) determined the effects of four soil water levels and two row spacings on the growth and yield of cultivars Forrest (MG V), Centennial (MG VI), and Braxton (MG VII). Irrigation was applied in the four treatments when (i) soil water matrix potential (Ψs) at both the 15 and 30 cm depths reached −70 J kg−1 (I1), (ii) Ψs at all depths between 15 and 76 cm reached −70 J kg−1 (I2), (iii) the same as in I1, but only after the R1‐R2 growth stage, and (iv) there was no irrigation (NI). Soybean was planted at interrow spacings (RS) of 0.5 and 1.0 m. Irrigation significantly increased yield of each cultivar at each RS in each year, but there were no yield differences among I1, I2, and I3 regimes at either RS. Average NI yields were 2.86,3.20 and 2.97 Mg ha−1 in 1982, 1983, and 1984, respectively. Yield increase from irrigation was 10,8, and 16% in 1982, 1983, and 1984, respectively. Irrigated yields of Forrest, Centennial, and Braxton were 3.47, 3.17, and 3.40 Mg ha−1, respectively, but water use efficiency was greatest with Forrest. Irrigation prior to R2 increased lodging up to 100%, and up to 50% when irrigated after R2. Severe lodging may have reduced irrigated yields. Relative yield increase from irrigation was limited by adequate rainfall and soil water storage, which resulted in high NI yields. The most efficient water regime was one based on an early maturing cultivar and γs measured at a depth of 76 cm.
Plant Tissue Degradation Measurement Using Image Analysis
Authors: Twidwell E. K. , Johnson K. D. , Bracker C. E. , Patterson J. A. , Cherney J. H. 
Published: July 2010

AbstractSeveral microscopic techniques have been used to measure plant tissue degradation by rumen microorganisms. Our objective was to develop a less subjective method for measuring plant tissue degradation using computer‐based image analysis rather than visual appraisal. Three millimeter segments of leaf blades from ‘Cave‐In‐Rock’ switchgrass (Panicum virgatum L.) were placed either directly into a fixative or into buffered rumen fluid for 48 h. Segments were retrieved and prepared for light microscopy by fixation, dehydration, embedding, trimming, and sectioning at a thickness of 2 μ. Tissues in cross section were measured with an optical image analysis system and each tissue type was classified as undigested, partially digested, or completely digested. The relative proportion of tissue types in undigested samples ranged from 1.9 ± 0.20% for phloem tissue to 35.9 ± 1.26% for mesophyll tissue. Standard deviations of measurements from digested samples ranged from 1.1 to 12.2%. Degradation of xylem and phloem was difficult to measure and had the highest standard deviations of 9.8 and 12.2%, respectively. This method requires approximately 15 min per sample, and although it is more time consuming than visual estimation methods, it has the advantage of measuring extent of digestion on an area basis more objectively than other methods currently used.
Differential Response of Two Cotton Cultivars to Fertilizer and Soil Potassium
Authors: Cassman K. G. , Kerby T. A. , Roberts B. A. , Bryant D. C. , Brouder S. M. 
Published: July 2010

AbstractCotton (Gossypium hirsutum L.) cultivars have considerable yield differences on vermiculitic soils where late‐season K deficiency occurs in California. A 2‐yr field study was conducted to evaluate cultivar differences in K use efficiency (defined as higher yield with a limited K supply) in relation to K uptake, K partitioning, and critical internal and external K requirements. The experiment had a split plot design with fertilizer‐K addition levels as mainplots, two cultivar subplots, and 10 blocked replications. Without K addition, yield was 29% (1986) and 35% (1987) greater in the K‐use‐efficient cultivar. Cultivar yield differences reflected greater boll retention at later fruiting positions, but was not related to differences in partitioning of K between vegetative and fruiting structures. When K supply was not limited, cultivar yields were similar. Yield of both cultivars was closely associated with leaf K concentration and soil K availability, but response curves indicated a lower leaf and soil K requirement for the K‐use‐efficient cultivar. The K‐use‐efficient cultivar had a higher K uptake rate during fruit development and greater total K accumulation, particularly at low soil K levels. Defining the physiological bases for such large genetic variation in K use efficiency will help to identify why the cotton plant is more sensitive to K limitation than other crops and will aid breeding efforts to develop germplasm more tolerant of a limited soil K supply.
Seasonal Variation in Chemical Composition of Forage Brassicas. I. Mineral Concentrations and Uptake
Authors: Guillard K. , Allinson D. W. 
Published: July 2010

AbstractLittle information is available on the mineral composition of summer‐ and autumn‐grown Brassica forages and the ability of these crops to provide the mineral requirements of grazing ruminants. This paper reports on seasonal variation of mineral composition and uptake in summer‐ and autumn‐grown turnip (B. rapa L.), rape (B. napus L.), swede (B. napus L.), and Tyfon [B. rapa L. ✕ B. pekinensis (Lour.) Rupr.]. Species were no‐till seeded into glyphosate [N‐(phosphonomethyl)grycine]‐suppressed sod in Connecticut on a Paxton fine sandy loam soil (coarse‐loamy, mixed, mesic Typic Dystrochrept) in 1983 and 1984. Concentrations of Ca, Mg, K, Cu, Fe, Mn, and Zn in summer‐grown species were similar to or exceeded concentrations in autumn‐grown species. Species grown during autumn, however, had greater concentrations of N and P. Foliage concentrations of Ca, Mg, N, and Mn were noticeably greater than root concentrations of the same minerals. Total mineral uptake in summer‐grown species was significantly greater for Ca, Mg, K, Cu, Fe, and Mn relative to uptake of these minerals in autumn‐grown species. Although species or seasonal effects, or species ✕ season interaction effects were significant for particular minerals, concentrations of Ca, Mg, P, K, N, and Fe were adequate or well above recommended levels for ruminants. Micromineral supplementation, however, may be needed for ruminants consuming Brassica grown on soils with low micromineral availabilities. Because of high mineral uptake, depletion of soil fertility would be rapid if native fertility is low and limited fertilizer is applied to these crops.
Thermal Time Requirements for Phenological Development of Peanut
Authors: Ketring D. L. , Wheless T. G. 
Published: July 2010

AbstractTemperature is a major environmental factor that determines the rate of plant development. Relation of thermal time to phenological development of peanut would provide a better understanding of this crop's response to temperature. Thermal time measured in day‐degrees (°Cd) was used to determine peanut (Arachis hypogaea L.) phenological development of a Spanish botanical‐type culitvar, Pronto, and a Virginia botanical‐type breeding line, OK‐FH15. Peanuts were grown under field conditions, on a Teller sandy loam (fineloamy, mixed, thermic, Udic Argiustoll) in 1985, 1986, and 1987. Irrigation plus rainfall ranged from 840 mm in 1985 to 400 mm in 1987. At 12 d after planting (DAP) when >80% emergence had occurred, 136 ± 18 °Cd had accumulated. Pronto produced more mainstem nodes (vegetative stage) than did OK‐FH15. Regression analyses indicated that both vegetative and reproductive development were highly correlated with °Cd for both genotypes. Incipient flowering (R1) began at 313 and 360 °Cd in 1985 and 1986, respectively. At 50% R1 in 1987, 410 and 498 °Cd had accumulated for Pronto and OK‐FH15, respectively. Both vegetative and reproductive stage development were slower with less water. Although attainment of a high reproductive stage value (7 to 9) does not indicate a high yield per se, it does indicate the degree of crop maturity. Seasonal accumulation of °Cd in 1985, 1986, and 1987 was 1456,1672, and 1473, respectively. Crop yields (pods) for the fullirrigation treatment were 312, 325, and 288 g m−2 for Pronto and 358, 405, and 308 g m−2 for OK‐FH15 in 1985, 1986, and 1987, respectively. Knowledge of °Cd accumulated can provide an estimate of harvest date as well as crop development stage.
Hybrid Cotton Pollination in Relation to Accumulated Degree Days
Authors: Phillips Sherman A. , Simpson James L. 
Published: July 2010

AbstractHybrid cotton (Gossypium spp.) pollination needs to be supplemented with honey bee (Apis mellifera L.) colonies. However, the relative importance of this supplemental pollination at specified time intervals during cotton bloom has not been determined. Therefore, our study was conducted to determine the quantity and quality of hybrid seed produced as a result of pollination during four consecutive, equal degree‐day (DD) periods. Four hybrid cotton seed production fields were established in Lubbock County, Texas. Accumulated DD (base temperature = 15 °C) were recorded for each field and divided into four equal periods within fields. Native and honey bee visitation was monitored every 2 d by counting the numbers observed per 100 flowers on the A‐line. All cotton bolls were hand harvested and sorted by date of bloom. Following harvesting, ginning, and delinting, seeds were counted and weighed, and percent germination was determined. Although the native and honey bee visitation level was adequate throughout each DD period, linear regression analyses indicate that coefficients of determination (r2) were low for (i) percent boll set and number of bees (native and honey bees), and (ii) number of seeds per boll and mean number of bees (native and honey bees). Pollination during the earlier DD periods resulted in higher percent germination, larger number of seeds per boll, and higher seed weight than seeds resulting from pollination during the latter bloom periods. We conclude that with proper honey bee management and pollination timing, the quality of hybrid seed produced will be improved by using only that from the first half of the bloom period
Weed Population Dynamics and Weed Control in the Peruvian Amazon
Authors: Mt. Pleasant Jane , McCollum R. E. , Coble H. D. 
Published: July 2010

AbstractIn traditional slush‐and‐burn agriculture, forest fallow is a primary agent in weed control. Stable continuous‐cropping systems could be expected to require a comprehensive program of weed management, probably including the use of herbicides. Weed control measures in a sequence of rice (Oryza sativa L.)‐corn (Zea mays L.)‐soybean (Glycine max L.)‐rice‐corn‐soybean were studied for 2 yr in Yurimaguas, Peru, with the following objectives to: (i) identify weed species resistant to the herbicide program in a continuous cropping system, and (ii) develop effective weed management practices for intensively managed cropping systems in the humid tropics. First‐crop weeds were 60% grass, 25% sedges, and 15% broadleaf weeds. The grass was composed of two species: large crabgrass [Digitaria sanguinalis (L.) Scop.] and goosegrass (Eleusine indica (L.) Gaertn]. Sixth‐crop weed population was 80% grass, 13% broadleafs and 7% spreading dayflower (Commelina diffusa Burm. f.); and itchgrass (Rottboelia exaltata L.f.) comprised 85% of the grasses. Metolachlor [2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐N‐(2‐methoxy‐l‐methylethyl) acetamide] controlled crabgrass, goosegrass, and most broadleafs in corn and soybean; but it did not control itchgrass. Metolachlor alone resulted in a weed population that was 97% itchgrass in the sixth crop. Sethoxydim {2‐[(1‐ethoxyimino)butyl]‐5‐[2‐(ethylthio)propyl]‐3‐hydroxy‐2‐cyclohexen‐1‐one}‐plus bentazon [3‐(1‐methylethyl)‐(1.H)‐2,1,3‐benzothiadiazin‐4(3H)‐one 2.2‐dioxide] on soybean controlled grasses including itchgrass, but broadleaf weeds and dayflower increased. Propanil [N‐(3,4‐dichlorophenyl) propanamide]‐plus‐oxadiazon {3‐[2,4‐dichloro‐5‐(1‐methylethoxy)phenyl]‐5‐(1,1‐dimethyl)‐1,3,4‐oxadiazol‐2‐(3H)‐one} on rice resulted in a mixed grass population. Rice was more vulnerable to weed pressure than either corn or soybean and appears inappropriate for this high‐input rotation because of the high cost of weed control.
Influence of Sample Dividing Method on Forage Quality as Determined by Nirs
Authors: Hall M. H. 
Published: July 2010

AbstractForage samples collected in the field are normally dried, coarsely ground, and subdivided to minimize time and expense required for secondary grinding, facilitate ease of sample handling, and reduce space needed for sample storage. The objective of this research was to determine the efficacy of four sample dividing methods to produce uniform subsamples for near infrared reflectance spectroscopy (NIRS) analysis. Sample dividing methods were: (1) quarter sectioning with a straight edge, (2) use of a gravimetric dividing apparatus, (3) mixing in a blender then dividing by quarter sectioning, and (4) mixing in a blender and dividing with a gravimetric dividing apparatus. Dividing method efficacy was evaluated by comparison of subsample quality. Average coefficients of correlation (r) between subsamples obtained using the divider apparatus were 0.97 and 0.08 for crude protein (CP) and acid detergent fiber (ADF), respectively. These r values were 4 and 6% higher for CP and ADF, respectively, than those obtained using the quarter sectioning method. However, r of the quarter sectioning method averaged for both CP and ADF improved nearly 7% by mixing the sample before dividing. The gravimetric dividing apparatus was superior to the quarter sectioning method in uniformly dividing both mixed and unmixed forage samples.
Temperature and Mepiquat Chloride Effects on Cotton Canopy Architecture
Authors: Reddy V. R. , Baker D. N. , Hodges H. F. 
Published: July 2010

AbstractCotton, (Gossypium hirsutum L.) when grown in a fertile, well‐watered, and suitable environment, produces excessive vegetative growth. Such luxuriant growth causes several production problems. A plant growth regulator, mepiquat chloride1 (1,1‐dimethylpiperidinium chloride; BASF Wyandotte Corp., Parsippany, NJ) has been found to reduce vegetative growth, but the crop responses to it appears to be temperature sensitive. An experiment was conducted to determine the crop responses to temperature in naturally lighted, temperature‐ and CO2‐controlled plant growth chambers. The experiment was conducted at five temperatures and measurements were made of several plant parameters. A preliminary experiment showed that mepiquat chloride (MC) caused a dramatic reduction in plant height and number of main‐stem nodes. A more detailed study showed that the impact of MC on main‐stem elongation was temperature dependent, with the greatest effect occurring at 35/25 °C day/night temperatures. The application of MC also caused a reduction in mainstem, vegetative‐branch and fruiting‐branch node formation. Leaf area was reduced on plants treated with MC at each of the temperatures. Specific leaf area (m2 kg−1) was also reduced on leaves from various positions on the plants. It appears that MC affects more than one physiological process. The primary effects were reduction in stem elongation, node formation, and leaf expansion. The reduced stem growth and leaf area development also caused greater leaf densities—probably a secondary or tertiary effect.
In Vivo Cotton Stem and Petiole Nitrate Reductase Activity
Authors: Chu Chang‐chi , Bariola Louis A. 
Published: July 2010

AbstractCotton (Gossypium hirsutum L.) plant stems and petioles are not generally considered to be major sites of nitrate reductase activity (NRA). Field studies were conducted to determine the significance of stem NRA and the potential of petiole NRA as an indicator of the N status of cotton. The contribution of various cotton plant parts to the in vivo plant shoot NRA (with endogenous nitrate only) was evaluated at five stages of plant development from the seedling stage to the flower bud stage (reproductive stages). In 1987 and 1988, samples were taken between 1000 and 1200 h under a clear sky from various plant parts of cotton (cultivar Deltapine 61) grown in a calcareous Holtville silty clay in the Imperial Valley, CA. Results showed that the plant stem (or hypocotyl) plus petiole contribution to the total plant shoot NRA increased from 14 to 72% as the plant progressed from vegetative growth to reproductive growth. Results indicated that cotton plants stems were high in NRA relative to leaf blades, except at the seedling stage. Samples taken from 35 cultivars and breeding lines in the same year under the same environmental conditions showed that the petiole NRA was high at the early flower bud stage. The petiole's average contribution of 52% of the total NRA of the top mature leaf indicates that petiole NRA may be useful as an indicator of N metabolism at the early flower bud stage of development.