bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ontogeny and Yield Response of Common and Tepary Beans to Temperature
Authors: Scully B. , Waines J. G. 
Published: July 2010

AbstractTemperature affects crop development and yield. In this study the effect of temperature on emergence, vegetative development, and yield of common bean (Phaseolus vulgaris L.) and tepary bean (P. acutifolius A. Gray) was compared. In the growth chamber nine common bean accessions were evaluated for emergence response over planting depths of 25, 50 and 75 mm, and at constant temperatures of 15,20,25,30, and 35 °C. The three depths had no significant effect on emergence between 20 and 30 °C, but at 15 and 35°C the increased depth significantly delayed emergence. The most rapid germination and emergence occurred at 30 °C under these controlled conditions. In the field emergence of the same common bean accessions was compared to tepary bean; tepary bean emerged about 1.5 d earlier than common bean at soil temperatures of 18 to 28 °C. The effect of temperature on vegetative development was evaluated by a linear heat unit system that measured base temperature (Tbase) and heat units to flowering. Under field conditions common bean had an average base temperature (Tbase) lower than tepary bean, and required more heat units to flower. Genotypic differences for base temperatures and heat unit requirements existed among accessions within both species. Temperature strongly affected the yields of both species when grown at Riverside, CA, on an Arlington fine sandy loam (coarse‐loamy, mixed, thermic Haplic Durixeralf). Tepary bean produced higher yields than common bean under hot summer conditions, but lower yields under early spring conditions.
Forage Quality and Yield of Wheat‐Vetch at Different Stages of Maturity and Vetch Seeding Rates
Authors: Roberts C. A. , Moore K. J. , Johnson K. D. 
Published: July 2010

AbstractRecent studies have shown that wheat (Triticum aestivum L.) grown in association with hairy vetch (Vicia villosa Roth) has a greater forage quality potential than wheat grown alone. The objective of this study was to evaluate the forage quality of wheat‐vetch with four vetch seeding rates at different stages of maturity. In the fall of 1983 and 1984, field plots were established at the University of Illinois South Farm at Urbana, IL. Wheat was planted alone at a rate of 324 pure live seeds (PLS) per square meter, or in combination with hairy vetch at rates of 0, 54, 108, or 162 PLS/m2 in a Flanagan silt loam (fine, montmorillonitic, mesic Aquic Argiudoll) soil. The forage was harvested when wheat was in the boot, anthesis, and milk stages of maturity. Mixed samples and individual fractions were analyzed using standard forage quality procedures. The vetch proportion was 18.4 and 9.9% in 1984 and 1985, respectively. Dry matter yield decreased with increasing vetch seeding rate and increased (P < 0.05) as the season progressed. Crude protein increased (P < 0.05) an average of 46.8 and 22.9% in 1984 and 1985, respectively, as vetch seeding rate increased from 0 to 162 PLS/m2; crude protein was primarily contributed by the vetch fraction, which contained twice as much protein as did wheat in both years. Digestibility (P < 0.05) increased an average of 12 and 1% as vetch seeding rate increased from 0 to 162 PLS/m2 in 1984 and 1985, respectively. Total cell wall concentration was not affected (P > 0.05) by vetch seeding rate. We conclude that the forage quality of wheat‐vetch sown with a vetch seeding rate of 162 PLS/m2 was higher than that of wheat‐vetch with lower vetch seeding rates.
Salt Effects on Germination, Emergence, and Seedling Mortality of Onion
Authors: Miyamoto S. 
Published: July 2010

AbstractGood stands of furrow irrigated onion (Allium cepa L.) are difficult to obtain in saline areas of the Southwest. This study examined salt effects on seed germination, emergence, and seedling mortality of five onion cultivars in a series of greenhouse experiments at diurnal temperatures of 15 to 25 °C. Germination exceeded 80% within 10 d at solution salinity of 20 dS m−1 or less. Cultivar effects on germination appeared initially, but diminished after approximately 1 wk. Seedling emergence from potted and subirrigated loamy sand declined significantly when salinity of irrigation water exceeded 4.9 dS m−1. This decline was apparently caused by hypocotyl mortality when the cotyledon came into contact with the salts accumulated at the soil surface, but not by reduced seed germination. Soluble salts accumulated mostly within the top 5 mm of the soil and the accumulation below 5 mm was minimal. The removal of the salted surface layer improved seedling emergence. Leaching of the surface‐accumulated salts into the seedling root zone 3 wk after seeding resulted in seedling mortality of significant magnitude; 12 and 20% in seedlings previously subirrigated with solutions of 2.8 and 4.9 dS m−1, respectively. A significant increase in seedling mortality was also observed when seedlings were sprayed twice after emergence with saline solutions of 28 and 39 dS m−1. The ability of cotyledons and seedlings to tolerate salinity, rather than the ability of seed to germinate in highly saline solutions, may be a limiting factor for obtaining good stands in furrow‐irrigated onion in saline areas.
Water Stress and Temperature in Relation to Seed Germination of Pearl Millet and Sorghum
Authors: Smith R. L. , Hoveland C. S. , Hanna W. W. 
Published: July 2010

AbstractPearl millet [Pennisetum glaucum (L.) R. Br.] is a potentially productive high‐quality grain crop that appears superior to sorghum (Sorghum bicolor L. Moench) in establishment under limited soil moisture. Our objectives were to compare sorghum and pearl millet seed germination under moisture stress conditions at two temperatures. Drought resistance was tested by germinating seeds in polyethylene glycol solutions with osmotic pressures of 0, 0.4, 0.8, and 1.2 MPa at 15 and 30 °C. At both temperatures pearl millet germination was less affected by increasing osmotic pressure (OP) than sorghum germination. At 30 °C sorghum germination decreased steadily as OP increased above 0 while pearl millet germination decreased significantly above an OP of 0.8 MPa. At 15 °C, pearl millet germination was always significantly higher than sorghum germination although the germination of both decreased steadily as OP increased. No germination occurred in either species at an OP of 1.2 MPa at 15 °C. The median germination time (MGT) at 30 °C for pearl millet was less than the MGT of sorghum under osmotic stress. There were no differences between sorghum and pearl millet MGT at 15 °C except at an OP of 0.4 MPa. The average MGT was higher at 15 °C than at 30 °C. Median germination time increased with each rise in OP, except for pearl millet between osmotic pressures of 0 and 0.4 MPa at 30 °C. The results indicate that pearl millet seed germinates better than sorghum seed under drought and lower temperature. The ability to germinate under stressful conditions could give pearl millet an advantage in stand establishment under the less than ideal conditions that frequently occur in the field.
Forage Selection by Cattle Grazing Orchardgrass‐Legume Pastures
Authors: Forwood J. R. , Stypinski P. , Paterson J.A. 
Published: July 2010

AbstractAnimal performance can be improved by overseeding legumes into grass swards, but little is known concerning consumption of various legumes over time. This study compared selection of various legumes to grass and weeds, and gathered information helpful in configuring grazing systems. Over two grazing seasons, esophageally fistulated steers (Bos taurus) sampled replicated pasture systems of; (i) orchardgrass (Dactylis glomerata L.) and red clover (Trifolium pratense L.) (OG‐RC), (ii) orchardgrass and birdsfoot trefoil (Lotus corniculatus L.) (OG‐BFT), and (iii) orchardgrass alone (OG) as spring and fall pasture near Columbia, MO. Steers also sampled the same treatments as summer hay regrowth, except that alfalfa [Medicago sativa L.] replaced birdsfoot trefoil in Treatment ii (OGALF). Grass dominated swards and steer diets, but selectivity ratios (SR) indicated no preferential selection for grass by steers. Dietary amounts of birdsfoot trefoil and red clover on pasture, and red clover and alfalfa on hay regrowth were similar, although availability of red clover was generally less than the other legumes. Thus, steers selected red clover to a greater extent over birdsfoot trefoil or alfalfa early in pasture and hay regrowth, and avoided both species during the fall. Average SR values indicate selectivity for weed species was least on OG‐RC followed by OG‐BFT, OG, and OG‐ALF. Diets from grass‐legume systems contained similar amounts of weeds and legumes, but weed proportion increased with time.
Soybean Cultivar Response to Metalaxyl Applied In Furrow and as a Seed Treatment
Authors: Guy S. O. , Oplinger E. S. , Grau C. R. 
Published: July 2010

AbstractPhytophthora root rot of soybean [Glycine max (L.)Merr.], caused by Phytophthora megasperma Drechs, f. sp. glycinea Kaun and Erwin, is a major disease problem in the Upper Midwest. This study was conducted to determine soybean performance with metalaxyl [N‐ (2,6‐dimethyl phenyl)‐N‐(methylacetyl)alanine methyl ester] fungicide on cultivars with different resistance and tolerance to this disease under low to moderate Phytophthora root rot potentials. Yield, plant density, and a Phytophthora root rot index were determined for metalaxyl treatments applied at labeled rates in furrow (IF) and as a seed treatment (ST) on 10 cultivars in two Wisconsin locations in 1985 and 1986, and IF at 0, 85, 170, and 340 g a.i. ha−1 on five cultivars at two 1987 locations. Yields of two, four, and five cultivars were increased by metalaxyl ST, IF, or IF+ ST treatments, respectively, in two moderate Phytophthora root rot diseased environments. Soybean yields with ST did not differ from IF for any cultivar. The cultivar AP200 with IF+ST treatment yielded more than IF alone. The AP200 plant stand at V2 stage was increased by IF+ST compared with the control. In furrow metalaxyl treatment decreased plant stand compared with ST for ‘S18‐84’. In two 1985 and 1986 environments, without detected Phytophthora root rot, soybean yields were decreased by 280 g ha−1 metalaxyl applied IF at 0.42, 0.25, 0.26, and 0.20 Mg ha−1 for S18‐84, AP200, ‘Century 84’, and ‘L1771’, respectively. However, in additional studies conducted in 1987 at two locations in the absence of Phytophthora root rot, metalaxyl applied at 85 to 340 g ha−1 IF did not influence the yield of five cultivars. Metalaxyl can be an effective fungicide for soybean Phytophthora root rot control; however, yield for certain cultivars may be adversely affected where there is no disease control benefit.
Soil Disturbance‐Residue Management Effect on Winter Wheat Growth and Yield
Authors: Wilhelm W. W. , Bouzerzour H. , Power J. F. 
Published: July 2010

AbstractThe need to reduce soil erosion, maximize soil water conservation, and optimize grain production in dryland cropping systems in the Central Great Plains has culminated in development of nontilled fallow systems. These systems have greatly reduced the degree of soil disturbance, and the amount and degree of residue incorporation. The objectives of this study were to evaluate the influence of soil disturbance and residue management on soil temperature, soil water, and winter wheat (Triticum aestivum L.) growth. Two field studies were established in 1981 and 1982 on an Alliance silt loam (Fine‐silty, mixed, mesic Aridic Argiustoll) with treatments consisting of various degrees of soil disturbance (moldboard plow, tandem disk, and no tillage), residue incorporation (on the soil surface or incorporated), and amount of residue applied (0.0, 0.5, and 1.0 of that produced by the previous crop). Decreased soil disturbance (tillage) and increased residue application decreased maximum, and increased minimum, soil temperatures. In all tillage treatments, soil water content showed a significant positive linear relationship to residue application rate. Grain yield was similar for all treatment factors, except tillage within the 1983‐1984 season when tilled (3.48 Mg ha−1) treatments produced more grain than the nontilled (3.20 Mg ha−1) treatment. Early development and growth of winter wheat was slowed by the presence of residues (surface or incorporated) or the absence of tillage. However, by completion of heading, phenology and yield were similar for all treatments. Cooler soil temperatures slowed development and growth during those stages when the meristem temperature was influenced most by soil temperature. However, after jointing, when air temperature and photoperiod were controlling development and growth, differences among treatments disappeared. Interaction of wheat development with soil temperature, air temperature, and daylength may contribute to the crop's inability to consistently capitalize, in terms of grain yield, on the greater amount of water stored in nontilled and mulched systems.
Environmental Effects on Nitrogen Dynamics in Soybean under Conservation and Clean Tillage Systems
Authors: Harper L. A. , Giddens J. E. , Langdale G. W. , Sharpe R. R. 
Published: July 2010

AbstractSoybean [Glycine max (L.) Merr.) obtains required N from the soil via root uptake of mineralized organic matter and fertilizer, and from the air by symbiotic gaseous N2 fixation and ammonia (NH3) absorption. The purpose of this study was to evaluate environmental and tillage effects on dynamic N transport under conservation (NT) and clean tillage (CT) management systems. Soil, plant, and microclimate measurements were made concurrently with estimates of gaseous N2 (using 15N2 techniques) and NH3 uptake from the atmosphere. Soybean growth and N uptake characteristics were similar in both tillage systems, except during a 14‐d drought period, which caused water stress in the CT system, but not the NT system. Nitrogen fixation decreased in the CT system to less than half that of the NT system fixation rate, resulting in a seasonal reduction of 29% in the CT system. Net NH3 transport varied from net absorption by the canopy during periods of adequate soil water to net evolution by the CT system during the drought‐stress period. Integration of the net NH3 flux density curves indicated that approximately 3% of the NT system and less than 1% of the CT system plant N was derived from the atmosphere. Also during the drought‐stress period, there was a net loss of plant N to the soil in the CT system indicated by soil and plant mass balance. Insect infestation was much greater in the NT system, reflecting insects' preference for a higher N crop, resulting in a significant N removal from the system. This study showed that soybean in these systems decreased soil N by about the amount of harvested N yield.
Elongation and Branching of Roots on Soybean Plants in a Carbon Dioxide‐Enriched Aerial Environment
Authors: Del Castillo D. , Acock B. , Reddy V. R. , Acock M. C. 
Published: July 2010

AbstractPlants grown in high CO2 concentrations ([CO2]) often have a higher root weight than those grown in low [CO2]. It is usually assumed that the plants with this extra root weight can explore a greater volume of soil and will, therefore, have more water available to them. To test this assumption, soybean [Glycine max (L.) Merr. cv. Forrest] plants were grown in outdoor, sunlit plant‐growth chambers in [CO2] of 330, 450, 600, and 800 μL L−1 throughout the growing season. The soil containers in the growth chambers had a glass side and new root growth appearing at the glass was measured and marked two or three times each week. Root weight at the end of the season (93 d after emergence) was 26 to 31% higher in [CO2]‐enriched chambers compared with the 330 μL L−1 treatment, and cumulative root length was approximately proportional to [CO2]. However, CO2 treatment did not affect the rate of elongation of individual root axes. Instead, there was a significant linear increase in the number of actively growing roots with increased [CO2]. Plants grown in 800 μL L−1 had 65% more actively growing roots than plants grown in 330 μL L−1. Thus, growing a plant in high [CO2] enabled it to explore a given volume of soil more thoroughly, but did not increase the volume of soil explored.
Wheat Volatilized Ammonia and Resulting Nitrogen Isotopic Fractionation
Authors: O'Deen W. A. 
Published: July 2010

AbstractMany agricultural crops show significant losses of N from flowering to maturity (during senescence). This research employs 15N fertilization to measure volatilization of NH3 directly from plants. A Plexiglas chamber was designed to isolate the aerial part of winter wheat (Triticum aestivum L. cv. Vona) from its growth medium following anthesis. The system was a continuous free‐flow, open design. Volatilized ammonia was trapped in surfaces of 0.1 M HCl continuously for three separate 90 d runs conducted in 1983, 1984, and 1985. The potted wheat yielded sensitive double‐peaked senescent N bands representing 3 to 4% of the N within the in‐chamber crop. The NH15‐N emission was from the internal N pool of the plant. Wheat tissue total N was determined by gravimetric Kjeldahl procedures employing tube diffusion. Fractionation of 14N and 15N isotopes, previously observed with tube diffusion and steam distillation, provided a basic model for similar fractionation caused by wheat volatilization of NH3. The varying atom percent 15N trends fit a model of continuously increasing wheat 15N content due to volatilization of NH3 with lower 15N content.
Grazing Winter Wheat: I. Response of Semidwarf Cultivars to Grain and Grazed Production Systems
Authors: Winter S.R. , Thompson E.K. 
Published: July 2010

AbstractMost wheat (Triticum aestivum L.) research in west Texas is conducted in ungrazed wheat that is managed solely for grain production (grain system). In contrast, most commercial wheat is planted early and grazed by cattle (Bos spp.) prior to management for grain production (grazed system). The objective of this research was to understand cultivar × production system interactions. Four semidwarf cultivars, TAM 105, Newton, Vona, and TAM 108, were grown in irrigated grain and grazed production systems for 3 yr. Grazed wheat headed 2.3 d later, had 57 and 62% as much above‐ground biomass and leaf area at heading, was 80% as tall, and yielded 80% as much as wheat grown in the grain system. There was a significant cultivar × system interaction for grain yield 2 yr (P = 0.088 in 1982, P = 0.001 in 1984) caused by differential cultivar response to yield constraints such as lodging, winterkilling, and shattering. In the 3‐yr combined analysis there was no cultivar × system interaction; however, the cultivar × system × year interaction for grain yield was significant (P = 0.003) because yield constraints within systems were not consistent across years. In 1984, extra fertilizer and insecticide reduced grain yield of TAM 108 by 18% (P = 0.001) in the grain system due to increased lodging while having no measurable effect on grain yield in the grazed system. If production systems frequently differ in type or degree of yield constraints, then breeders and agronomist must be concerned with cultivar × system interactions.
Transplanting of Maize During the Winter in India
Authors: Khehra A. S. , Brar H. S. , Sharma R. K. , Dhillon B. S. , Malhotra V. V. 
Published: July 2010

AbstractMaize (Zea mays L.) cultivation during the winter is a new cropping practice in North India. In this cropping system, maize has slow seedling growth associated with low winter temperatures. If the crop can be grown in a nursery during this slow‐growth period and then transplanted, the crop duration in the main field is shortened. Therefore, the present study was conducted to determine if maize could be successfully transplanted to the field. Other objectives were to evaluate the effect of seedling age, and date and method of transplanting. Experiments were done in the field during two or three winter seasons at two locations. Among the transplanting treatments, 40‐d‐old seedlings transplanted on 24 December and 60‐d‐old seedlings on 16 January resulted in the highest grain yields. Grain yields from these transplantings were 92 to 94% (5314–5402 kg ha−1) of the yield of the crop direct seeded on 9 November (5743 kg ha−1), the optimum sowing time. Grain yield was significantly reduced when younger (up to 20 d) or older (up to 80 d) seedlings were used, with drastic reduction in the latter case. Transplanting of 60‐d‐old seedlings on 24 December and 80‐d‐old seedlings on 16 January yielded only 10 to 12% as compared with the best transplantings. Delayed transplanting (6 February) also decreased grain yield. The comparisons between methods, transplanting on the southern slope of the east‐west ridge or on a flat seed bed, showed that the former improved grain yield. The present study indicates that maize can be successfully produced by transplanting 40‐d‐old seedlings on 24 December and 60‐d‐old seedlings on 16 January, and that transplanting should preferably be done on the ridged seedbed.
Soybean Cultivar Response to Tillage Systems and Planting Date
Authors: Elmore Roger W. 
Published: July 2010

AbstractThe soybean [Glycine max (L.) Merr.] production area in the USA planted with reduced‐tillage practices has doubled in the last two decades. Previous studies show that soybean cultivars yield similarly in various tillage systems when planted in well‐drained soils. Reduced‐till farmers are planting earlier than in the past, but planting date studies with various tillage systems and cultivars have not been reported. A 3‐yr field study was conducted to compare soybean cultivar responses to various tillage systems at various planting dates. Six soybean cultivars were planted on three dates each year (average planting dates were: 7 May, 29 May, and 15 June) with two tillage systems: three passes with a tandem disk in the spring (TD) or notill (NT). A Hastings silt loam soil (fine, montmorillonitic, mesic Udic Argiustoll) was used in 2 yr and a Crete silt loam soil (fine, montmorillonitic, mesic Pachic Argiustoll) was used in the other. The determinate cultivar yielded less when planted on 7 May than on 29 May at 2.72 and 3.14 Mg ha−1 respectively. Indeterminate cultivars had similar yields for these two dates with 2.99 Mg ha−1. Yield of TD was 0.18 Mg ha−1 less than that of NT for 7 May, but was 0.19 Mg ha−1 greater than that of NT for 29 May. There were no tillage × cultivar or tillage × planting date × cultivar interactions. Although planting date was shown to be an important factor in cultivar selection, this study has shown that planting date is not a critical factor in the tillage‐cultivar selection process. The best yielding cultivars in tilled performance tests will likely be the same as those from a no‐till performance test, irrespective of planting date.