bluuebunny/crossref_metadata_2025_split huggingface dataset:
Manganese Deficiency and Toxicity Sensitivities of Soybean Cultivars
Authors: Ohki K. , Wilson D. O. , Anderson O. E. 
Published: July 2010

AbstractSoybean [Glycine max (L.) Merr.] cultivars vary in plant growth response to Mn deficiency and toxicity. Cultivar selection for field studies to evaluate responses to Mn deficiency and toxicity is important. The objective of this study was to determine the differential sensitivity of cultivars to Mn deficiency and toxicity prior to regional field studies on the diagnosis and correction of Mn problems in the production of soybeans.For evaluating relative ranking of cultivars sensitive to Mn deficiency, seven soybean cultivars were grown in solution culture at severe (5 µg Mn/liter) and mild (50 µg Mn/liter) deficiency levels and compared with controls, (1,000 µg Mn/liter). For toxicity evaluations, seven cultivars were grown at severe (20 mg Mn/liter) and mild (10 mg Mn/liter) toxicity levels with controls at 0.5 mg Mn/liter.Cultivar sensitivity to Mn deficiency was partially dependent on the level of deficiency stress. ‘Davis’, ‘Lee 74’, ‘Bragg’, and ‘Pickett 71’ were the most sensitive under severe deficiency and Lee 74, Bragg and ‘Hutton’ were the most sensitive under mild deficiency. Davis, Lee 74, Pickett 71, Bragg, and ‘Ransom’ were the most sensitive to severe Mn toxicity at the severe Mn toxicity level. At mild toxicity, shoot weights as percent of control were similar for all cultivars. Visual symptom ratings and leaf blade Mn concentrations were significantly correlated with shoot dry weight as percent of control for Mn deficiency and toxicity stresses. The increased sensitivity to Mn toxicity by Lee 74 compared to that previously reported for the ‘Lee’ cultivar may be a result of genetic changes which occurred during the development of Lee 74.
Influence of Induced Lodging on Pod Distribution and Seed Yield in Soybeans1
Authors: Noor Ramli Bin Mohd , Caviness C. E. 
Published: July 2010

AbstractLodging occurs frequently in soybeans [Glycine max (L.) Merr.] and has been shown to reduce yields of indeterminate cultivars under most conditions: Information is limited on effects of lodging on determinate cultivars, types commonly grown in the southern U. S. Influence of lodging on pod distribution and seed yield was measured during a 2‐year study in the field on ‘Forrest’, a determinate cultivar and ‘R74‐334’, a semideterminate strain, at three stages of growth. Growth of the semideterminate strain in Arkansas resembled that of indeterminate cultivars grown in the Midwest. Plants were lodged at 0°, 45°, and 90° angles from the vertical at a vegetative stage (V8) and two reproductive stages (R2 and R4).A significant yield reduction was obtained from induced lodging at full pod (R4) but none at the vegetative (V8) or full bloom (R2) stage of development. The determinate cultivar and semideterminate strain were affected similarly by the lodging treatments. Lodging resulted in an increase in percentage of pods on lateral branches at stages V8 and R2 but no change was noted at R4. Number of seeds per pod was not affected by plant lodging. Lodging affected the number of seeds per plant more than seed size. Decrease in seed yield, therefore, was primarily due to reduction in number of seeds produced on lodged plants.
Apparent Photosynthesis, Evapotranspiration, and Light Penetration in Two Contrasting Hard Red Winter Wheat Canopies1
Authors: Johnson R. C. , Witters R. E. , Ciha A. J. 
Published: July 2010

AbstractCrop canopy structure is highly variable in time and space influencing canopy light interception, apparent photosynthesis (AP), and evapotranspiration (ET). Our objectives were to relate AP and ET to light interception, leaf area index (LAI), temperature, and yield in two row‐spacings of winter wheat (Triticum aestivum L.) in a field environment. ‘Wanser’ winter wheat was planted at 20 — (140 kg seeds ha−1) and 40 — cm (70 kg seeds ha−1) row spacings in Ritzville silt loam (Mesic Calciorthidic Haploxerolls). Two aluminum frame chambers covered with mylar and occupying 0.74 m2 of soil surface area were used with infrared gas analyzers to measure AP and ET in each row spacing from the respective differences between chamber intake and exhaust CO2 and H2O concentrations. On clear days from stem extension to the milky ripe developmental stage and when incoming short‐wave solar radiation (SR) was 700 War−2 (± 140 Wm−2), best fit quadratic polynomial regression curves of AP and ET were obtained for each row spacing. Interception of SR across rows in each spacing was measured after anthesis with tube solarimeters 2, 27, and 53 cm above the soil surface.Values of LAI, AP, and ET were generally greater in the 20‐ than hi the 40‐cm spacing. After anthesis, LAI declined sharply in both spacings resulting in decreasing AP values; but ET was not greatly reduced. In contrast to days before anthesis, average air temperatures after anthesis were generally greater than average leaf temperatures. Sensible heat transferred from air to foliage was apparently an energy source promoting ET late in crop development. After anthesis, SR differed significantly between spacings at 2 cm, but not at 27 or 53 cm above the soil. Plant heights in both spacings were about equal averaging 70.3 cm. At 18 days after anthesis (watery ripe stage), the 20‐cm spacing had about 22% less SR 2 cm above the soil than the 40‐cm spacing. At that tune AP and LAI values were about equal between spacings so that the greater SR intercepted by 20‐cm spacing was apparently by tissue of low photosynthetic capability, such as dead or senescing leaves and tillers. Both spacings had statistically equal grain yields (2,102 kg ha−1 average); but the 20‐cm spacing had 67% more heads m−2, resulting hi more kernels nr*, than the 40‐cm spacing. The 40‐cm spacing had greater kernel weights and about 2.5 more kernels/head than the 20‐cm spacing. Increasing winter wheat yields by increasing post‐anthesis light interception appears unlikely unless sufficient water were available to maintain dense stands with high post‐anthesis LAI values.
Irrigation Scheduling and Plant Population Effects on Growth, Bloom Rates, Boll Abscission, and Yield of Cotton1
Authors: Guinn G. , Mauney J. R. , Fry K. E. 
Published: July 2010

AbstractTechniques are needed for conserving water and shortening the cotton (Gossypium hirsutum L.) fruiting season in irrigated areas. We conducted field tests at Phoenix, Arizona during the summers of 1978 and 1979 to determine the influence of delaying the first irrigation on subsequent growth, fruiting, and yield of cotton grown in an Avondale clay loam (fine‐loamy, hyperthermic, Typic Torrifluvents). In 1978, the first post‐plant irrigation was applied when the first flower bud (square) became visible (E) or 14 days later (L). Two levels of irrigation during the remainder of the season, normal (N) or 0.6 normal (D), were used as subplots. Delaying the first irrigation slowed growth, square production, and leaf area development, and slightly decreased the number of bolls set by any given date. Despite these apparent adverse effects the LN treatment produced heavier bolls, fewer damaged bolls, and the highest yield. Although LN received 13 cm less water than EN, it produced an average of 606 kg more seed cotton per ha. Water deficit during the remainder of the season (D) greatly decreased growth and yield. In 1979, the first post‐plant irrigation was applied at the time of first visible square (E), 7 days later (M), or 16 days later (L). Two plant populations, 94,000 (Hi) and 52,000 (Lo) plants per ha were also variables. The final irrigation was applied 13 August to shorten the season. Despite a 16‐day delay in the first irrigation, one less irrigation, and a short‐season (early termination), L produced about the same yield as E. The low population produced slightly fewer blooms, but retained more and produced slightly higher yields than the high population. Treatment MLo produced the highest yield, and LLo gave the greatest water‐use efficiency. Delaying the first irrigation conserved water and gave satisfactory yields despite early termination in 1979.Although water deficit during the bloom stage hastened cutout, delaying the first irrigation had little effect on earliness. Likewise, low plant population caused no appreciable delay in setting the crop.
Morphological Development of Rice Seedlings in Water at Controlled Oxygen Levels1
Authors: Turner Fred T. , Chen Cy‐Chain , McCauley Garry N. 
Published: July 2010

AbstractGermination and seedling establishment of rice (Oryza sativa L.) is usually less than optimum in water saturated and flooded soils apparently because of a deficiency of available oxygen (O2). However, the effect of low O2 level on rice germination and seedling development is not well defined. To evaluate the effect of varying O2 level on rice seedling development and to identify rice cultivars which may be more tolerant to the low O2 concentrations associated with water saturated rice soils, seeds of four rice cultivars were incubated in water containing six O2 concentrations. Gas flow meters and regulators allowed mixing of air and N2 gas to obtain O2 levels of 21, 10.5, 5.3, 2.0, 1.0, and 0% (99.995% N2 gas) which were bubbled through special water filled containers placed in a growth chamber providing 400 microeinstein m−2 sec−1 light intensity, 12‐hour day, and 27 C constant temperature.Oxygen concentration had little effect on coleoptile emergence from rice seed but low O2 levels enhanced coleoptile elongation. Maximum coleoptile length (20 mm) occurred at 0% O2, making it appear that rice germinated at very low O2 levels. However, it was apparent that root and shoot (leaf) growth were inhibited at 0% O2, providing evidence that low O2 levels can restrict rice stand establishment.The critical O2 level for maximum shoot elongation appeared to be about 5%. The critical O2 level for root elongation was less evident. Roots of ‘Labelle’ and “Bellemont’ seedlings reached maximum length at O2 levels as low as 5% whereas roots of ‘Calrose 76’ and ‘M 101’ seedlings continued to increase in length as the O2 level was maintained at 10.5 and even 21%. Differences in cultivar tolerance to low O2 levels were observed among the 10 cultivars evaluated. Also, rice cultivars exhibited tolerance to low O2 levels in terms of one parameter (root, shoot, or coleoptile length) without showing tolerance in terms of the other two parameters.
Descriptive Comparison of Senescent and Nonsenescent Sorghum Genotypes1
Authors: Duncan R. R. , Bockholt A. J. , Miller F. R. 
Published: July 2010

AbstractUnder normal field conditions, leaves of many typical sorghum [Sorghum bicolor (L.) Moench] lines such as BT×378, RT×7000, RT×2536, and SC 214(IS 1598C) senesce after grain maturity. In the field, several upper leaves of three partially converted lines [SC0056 (IS 12568), SC0599 (Rio), and SC0170 (IS12661)] from the sorghum conversion program remained green and apparently vigorous after grain maturity. This phenomenon of green leaf retention after the grain reached physiological maturity was termed “nonsenescence”. The purpose of this study was to compare standard (senescent) and nonsenescent lines to determine characteristics which describe differences between the two genotypes and to define desirable qualities of the nonsenescent lines.Senescent and nonsenescent lines were evaluated in the field for three growing seasons, 1974 to 1976, at College Station, Texas. The soil type was Ships clay (Udertic Haplustoll) intergrading toward a Norwood clay loam (Typic Udifluvent). Several plant characteristics (growth parameters, yield and yield components, basal tiller production, stem diameter, percent basal stem sugar concentration, and total leaf blade chlorophyll content) were measured to characterize genotypic differences. Experimental design was a randomized complete block with four replications. Growth data were recorded during the reproductive stage of development. The nonsenescent genotype required 2 days longer to reach 50% anthesis, averaged 3 to 4 cm shorter height, produced two to three more basal tillers per plant, had larger stem diameters, maintained higher basal stem sugar concentrations, and produced higher leaf blade chlorophyll contents than did the senescent genotype. Data involving leaves (green leaf number and weight, senesced leaf number and weight, leaf area index, leaf area duration, and leaf area ratio) favored the nonsenescent genotype. The grain‐leaf ratio of the senescent genotype exceeddthat of the nonsenescent genotype 30 days after anthesis because of a consistent reduction in leaf area due to senescence. Except for test weight (which was higher in the nonsenescent genotype), yield and yield components were generally inconsistent between genotypes.Parameters which could reasonably be measured in a breeding program to select for nonsenescent genotypes might include stem diameter and stem sugar concentration, tiller counts of a ratoon crop, and number of green leaves retained after grain maturity. Leaf area and chlorophyll measurements after the grain has reached physiological maturity might provide more conclusive Information on nonsenescence capability, but would probably not be feasible in a breeding program.
Selected Determinate Soybean Cultivar Yield Responses to Row Spacings and Planting Dates1
Authors: Boquet D. J. , Koonce K. L. , Walker D. M. 
Published: July 2010

AbstractPrevious studies to determine row spacing (RS)‐planting date (PD) effects on yield of determinate soybeans [Glycine max (L.) Merr.] in the southern USA have been conducted north of 33° Lat, and have produced conflicting results. Current data on the effects of these planting variables are not available for a large portion of the Gulf Coast area that now supports a large and rapidly expanding soybean industry. The objectives OP this experiment were to study: 1) the effects of selected RS and PD on yield of selected cultivars of determinate soybeans; 2) the interaction of RS with PD; and 3) the interaction of cultivars with RS and PD.Five cultivars, ‘Forrest,’ ‘Davis,’ ‘Lee 74,’ ‘Centennial,’ and ‘Bragg’ were planted in RS of 25, 50, and 100‐cm on 6 PD between 15 April and 1 July in 1976, 1977, 1978, and 1979. The field plots were located on a Mhoon silty clay soil (Typic Fluvaquent). Averaged over years, the five cultivars evaluated produced significantly higher yields when grown in 25 and 50‐cm RS compared with the 100‐cm RS. The interaction between cultivar and RS was significant due to variability among cultivars in the yield increase when RS was reduced; 3 q/ha with Davis and Bragg, 4 q/ha with Lee 74, and 6 q/ha with Forrest and Centennial. The size of yield increases resulting from reduced row spacing was relatively consistent across PD. Because lower yields were recorded at all three RS at nonoptimum PD the yield increases, when expressed as a percentage of the yields obtained in 100‐cm rows, were larger at the nonoptimum dates, however. Optimum PD was not affected by RS but differed among cultivars. Forrest and Lee 74 had highest yields when planted on 15 May while the other three cultivars had similar yields at PD from 1 May to 1 June. Results indicated that significantly higher yields are possible with current determinate cultivars when both RS and PD are selected for individual cultivars.
Response of Sunflower to Uniformity of Plant Spacing1
Authors: Robinson R. G. , Ford J. H. , Lueschen W. E. , Rabas D. L. , Warnes D. D. , Wiersma J. V. 
Published: July 2010

AbstractPlant spacing in the row is variable in most sunflower (Helianthus annuus L.) fields. The amount of yield loss from moderately uneven stands of sunflower should be known before undertaking expensive techniques to increase uniformity of plant distribution. The objective of this research was to measure the effects of uniformity of plant distribution on sunflower seed yield, plant growth, and seed quality. Four plant distributions of oilseed and nonoilseed cultivars in rows 76 cm apart and in a population of 49,000 plants/ha were established at five locations in Minnesota in 1979 and 1980. Soils were Typic Haplaquolls, Aerie Calciaquolls, and Aerie Haplaquepts. Plant distributions were: single plants 27 cm apart; paired plants 53 cm apart; five plants each 13 cm apart, 80‐cm space; seven plants each 9 cm apart, 80‐cm space, single plant, 80 cm space. Uniformly spaced, single plants lodged least and produced heads of lowest moisture percentage at harvest and seed of highest yield and oil percentage. Yield reductions from uneven plant distributions ranged from none to 31% and averaged 10%. Greater lodging was the most consistent detriment of nonuniform plant spacing. The magnitude of differences in seed quality among the plant distributions was small and consequently of relatively little economic importance.
Response of Sugarcane to Silicate Source and Rate. I. Growth and Yield1
Authors: Elawad S. H. , Gascho G. J. , Street J. J. 
Published: July 2010

AbstractSugarcane (a complex trispecies hybrid of Saccharum) is one of few crops which are highly responsive to applications of silicate materials. Variety ‘C.P. 63‐588’ was grown on a Pahokee muck soil (euic, hyperthermic Lithic Medisaprist) to evaluate effects of silicate sources and rates on growth of cane and sugar yield. Data were collected from the initial planting and a subsequent ratoon crop. Silicate materials were applied to 79.2 m2 field plots at the rates of 0, 5, 10, 15, and 20 metric tons/ha of TVA slag, Florida slag, and Portland cement. A factorial experiment was established in a randomized complete block design with five replications. The silicate materials were broadcast by hand and then thoroughly mixed with the soil by a disc harrow. Growth was measured as plant height, stem diameter, and number of millable stalks. Yield was determined as metric tons of cane and sugar per ha. Application of silicate materials increased plant height, stem diameter, number of millable stalks, and cane and sugar yields in both plant and ratoon crops. Addition of 15 metric tons/ha of silicate materials increased cane and sugar yields by 68 and 79% in the plant crop, and by 125 and 129% in the ratoon crop, respectively. Although there was no significant difference among the silicate materials in the plant crop, Florida slag increased growth and yield more than the other two materials in the ratoon crop. The vital role of Si in sugarcane growth was evident by increased plant size and increased tillering.
Yield and Yield Components of Four Spring Barley Cultivars Under Three Tillage Systems1
Authors: Ciha A. J. 
Published: July 2010

AbstractSoil erosion is a serious problem in the Palouse Region of the Pacific Northwest. A field study was conducted under three environmental conditions [Palouse silt foam (fine‐silty, mixed, mesic, Pachic Ultic Hapoxerolls) during 1980 and Athena silt loam (fine‐silty, mixed, mesic, Pachic Haploxerolls) during 1979 and 1980] to determine the effects of three tillage systems on grain yield and yield components of four commercial spring barley (Hordeum vulgare L.) cultivars, ‘Steptoe’, ‘Advance’, ‘Vanguard’, and ‘Kimberly’. The experiments were conducted using conventional tillage (fall plow and spring disk), conservation tillage (fall chisel and spring disk), and no‐tillage (standing stubble) systems.Grain yields were not significantly influenced by tillage; however, yields under no‐tillage were consistently greater than yields from conventional tillage. Test weight, 100‐kernel weight, and percent plump kernels were significantly increased with no‐tillage when compared to conventional tillage, but no‐tillage barley had significantly fewer heads/m2 and reduced plant height than conventional tillage. Tillage practice had no significant effect on seeds per head. Environment significantly influenced all yield and yield components. Significant tillage ✕ environment interactions for test weight, height, and 100‐kernel weight did exist. While significant differences in yield and yield components existed among the cultivars examined, no cultivar ✕ tillage interactions were present for any of the parameters examined in this experiment. Results suggest that spring barley cultivars developed and selected under conventional tillage systems are equally adapted to no‐tillage systems. Since grain yields were not significantly affected by tillage system under the conditions of this experiment, the use of no‐tillage systems for spring barley production should be adapted whenever possible to reduce soil erosion.
Double Cropping Cotton and Wheat1
Authors: Smith C. Wayne , Varvil J. J. 
Published: July 2010

AbstractSeveral “fast fruiting” or “early” genotypes of cotton (Gossypium hirsutum L.), have been developed over the past several years to reduce losses associated with adverse autumn weather, allow later planting to escape early season disease problems, reduce insect and weed pests associated problems, and to reduce the inputs required to make and protect an acceptable yield. These earlier maturing types may provide the opportunity of year‐round land use by double cropping with a winter grain.Four genotypes, ‘Deltapine 16’, ‘Rex 713’, ‘Coker 304’, and Arkugo 4, were included to represent a range of genetic maturity. These entries were compared when monocropped or double cropped after wheat (Triticum aestivum L.) in a prepared seedbed or planted directly into the wheat stubble. The experimental design was a split plot of a randomized complete block. The test site was Memphis silt loam (a fine‐silty, mixed, thermic Typic Haplustalfs). All other production practices were normal for the locale with no irrigation.Results indicated that seedcotton yields of double cropped cotton, as compared to monocropped, would be reduced by 35 to 50% with an early maturing genotype and 50 to 65% with full season, Delta cultivars. These results would discourage double cropping with wheat in the northern areas of the U.S. cotton belt. However, lint yields of double cropped Arkugo 4, the fastest fruiting type studied, were such that further development of early season types should be encouraged.No detrimental effects of double cropping on quality of fiber or percent lint were noted in 1976 or 1978.