bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Soybean Cultivars in Monoculture and Relay Intercropping Systems1
Authors: McBroom R. L. , Hadley H. H. , Brown C. M. , Johnson R. R. 
Published: July 2010

Cultivars of soybean [Glycine max (L.) Merrill] were grown in monoculture and in relay intercropping systems at Urbana, Ill. in 1978 and 1979 and at DeKalb, Ill. in 1979 to determine if there is a genotype ✕ cropping system interaction that would require separate breeding programs for maximum progress in developing new cultivars for use in different systems.Relay intercropped soybeans were shorter, lodged less, and produced lower yields than soybeans grown in monoculture. No significant genotype ✕ cropping system interaction for yield was detected when soybeans were interplanted in small grains [winter wheat (Triticum aestivum L.) or spring oats (Avena sativa L.)] and planted in monoculture on the same day. Early season competition in intercropping was not sufficient in these experiments to cause differential performance among genotypes. Our results suggest that separate breeding programs are not required to develop cultivars for monoculture or intercropping.
Inheritance and Identification of a Carotenoid Pigment in Orange Alfalfa Roots1
Authors: Brick M. A. , Barnes D. K. , Vance C. P. 
Published: July 2010

An alfalfa (Medicago sativa L.) plant with orange root tissue was observed while evaluating for root disease resistance. The mode of inheritance and chemical nature of the orange color was investigated. Crosses were made between the orange‐rooted plant and a normal white‐rooted plant to produce S1, F1, F2, and backcross generations. Chemical analysis of the orange root pigment was conducted to determine its character and concentration.Genetic studies revealed that the orange root color was controlled by a single recessive gene (or) with tetrasomic inheritance. The orange root phenotype was expressed only in the nulliplex condition. Chemical analysis indicated that the pigment which conditioned the orange root color was poly‐cis‐lycopene. The orange‐rooted genotype contained 107 ÷Mg/g fresh weight of the pigment in the root while the white‐rooted genotype contained only a trace of total carotenoids In the root. The carotenoid types and concentrations in the foliage were similar for both white and orange‐rooted phenotypes.
Reproductive Response of Soybeans to Night Interruption1
Authors: Lawrence B. K. , Fehr W. R. 
Published: July 2010

Artificial lights may be used to delay flowering of soybean [Glycine max (L.) Merr.] cultivars. Previous research has suggested that night interruption imposed every other night would delay flowering as much as every‐night interruption. Our objective was to evaluate the reproductive development of cultivars when exposed to night interruption every night compared with exposure every other night. One cultivar of each Maturity Group 00 through V was grown in the field at Ames, Iowa during 1978 and 1979. The four light treatments imposed every night or every other night included illumination with incandescent light from sunset to sunrise, 2300 to 0030 hours, 0030 to 0200 hours, or 0200 to 0330 hours. Control plots were not exposed to artificial light.The average number of days that reproductive development was delayed beyond the control was twice as great for the every‐night treatments as for the every‐other‐night treatments. Illumination from sunset to sunrise delayed reproductive development significantly more than the treatments of night interruption for 1.5 hours. Night interruption near the end of the dark period (0200 to 0330 hours) delayed reproductive development more than the earlier interruptions.The results did not support the hypothesis that light treatments every other night would delay reproductive development as much as every‐night interruptions. The lighting regime needed to delay reproductive development will depend on the photoperiod requirements of the cultivars and duration of the delay that is desired.
Diallel Analysis of the Photoperiodic Response of Maize1
Authors: Rood S. B. , Major D. J. 
Published: July 2010

A diallel cross from eight early maturing maize (Zea mays L.) inbreds was used to investigate the inheritance of photoperiodic response and the role of this response in adaptation to high latitudes. Days from emergence to flowering increased for six of the inbreds and all of the hybrids as the photoperiod was increased from 14 to 22 hours. The photoperiodic response was divided into a basic vegetative phase, which is the time to flowering under ideal photoperiod conditions, and a photoperiodinduced phase. The maximum optimal photoperiod was the longest photoperiod at which no photoperiodinduced delay of flowering‐time was observed; the slope of the photoperiod response was the photoperiod sensitivity.Incomplete dominance for decreased basic vegetative phase (BVP) was observed and an inheritance analysis of BVP produced values for the diallel that were very similar to those obtained previously for flowering‐time in field trials. Heritabilities were high for the basic vegetative phase and low for other photoperiod characteristics. Specific combining ability effects were significant for photoperiod sensitivity and maximum optimal photoperiod; reciprocal effects were not significant. General combining ability (GCA) efffects for the basic vegetative phase were correlated with GCA effects for flowering time from field trials in Alberta. For a photoperiod similar to that of 50° N Lat, the average photoperiod‐induced delay in floweringtime of the diallel hybrids was 1.5 days. Thus, photoperiod is of only minor importance in the developmental adaptation of the early maturing maize genotypes examined as flowering‐time in field trials was closely related to BVP alone.
Yields and Yield Components of Flax, Soybean, Wheat, and Oats Treated with Morphactins and Other Growth Regulators for Senescence Delay1
Authors: Dybing C. Dean , Lay Charles 
Published: July 2010

Objectives of this work were to determine (a) effects of regulator‐promoted delay of senescence on seed yield of flax (Linum usitatissimum L.), soybean (Glycine max (L.) Merrill), wheat (Triticum aestivum (L.) em Thell), and oats (Arena sativa L.), and (b) morphological ponents of any such yield response. For flax, delay of leaf yellowing 40 to 60 days after full bloom was negatively correlated with yield for regulator applications made at vegetative, bud, and bloom stages. Postbloom applications of TIBA (9,3,5‐triiodobenzoic acid) or SD‐8339 (N‐(phenylmethyl‐9‐(tetrahydro‐9/‐/‐ pyran‐9‐yl)‐9H‐purin‐6‐amine) delayed canopy yellowing under field conditions without affecting yield. The morphactins chlorflurenol (methyl 2‐chloro‐9‐hydroxyfluorene‐9‐carboxylate) and dichlorflurenol (methyl 2,7‐dichloro‐9‐hydroxyfluorene‐9‐carboxylate) applied postbloom at rates of 95 and 100 g/ha, respectively, consistently delayed senescence of flax. Chlorflurenol significantly enhanced yield in two of six trials; dichlorflurenol increased yield in one of five trials. In spite of morphactin effects prolonging leaf and chlorophyll retention, enhancing shoot growth, and renewing flowering and fruiting, yield effectiveness was sometimes lowered by reduction in size of primary seeds, pre‐harvest loss of primary fruits, and low seed set for secondary fruits. Yield enhancement by chlorflurenol was increased by application of a fungicide.Senescence delay in soybean caused by chlorflurenol, dichlorflurenol, or BA (6‐benzylamino)purine) did increase yield. Chlorflurenol treatment (500 or 1,000 g/ha) after anthesis increased seed yield of wheat, and dichlorflurenol applied in boot stage at 1,000 g/ha increased yield of oats; rate of senescence was unaltered in both crops.
Effects of Defoliating Pests on Soybean Canopy CO2 Exchange and Reproductive Growth1
Authors: Ingram K. T. , Herzog D. C. , Boote K. J. , Jones J. W. , Barfield C. S. 
Published: July 2010

Defoliation during reproductive growth of soybean [Glycine max (L.) Merr.] may significantly reduce yields. The objective of this study was to elucidate the relationships among organism‐induced defoliation, CO2 exchange rates, and reproductive growth in fieldgrown soybean. Soybean (‘Bragg’) plots were sprayed a factorial design with diflubenzuron (0.035 kg a.i./ha) and a benomyl‐maneb mixture (1.12 a.i./ha) on two dates, first at early flowering (5 August) and again at early pod set (19 August). Diflubenzuron application prevented defoliation by velvetbean caterpillar (Anticarsia gemmatalis Hubner). By 12 September, LAI was reduced from 5.5 to 2.8, leaf dry weight from 185 to 110 g/m2, and midday light interception from 94 to 72% in defoliated as compared to non‐defoliated plots. While canopy specific leaf weight (SLW) increased in all treatments during the experimental period, SLW was 1.0 mg/cm2 higher in defoliated than non‐defoliated plots. On 4 September defoliated plots were sprayed with diflubenzuron (0.035 kg a.i./ha) and carbaryl (0.56 kg a.i./ha) prevent further leaf loss.Canopy CO2 exchange was measured at various photosynthetic photon flux densities (PPFD) to develop photosynthesis light response curves. Net canopy photosynthesis at 1,500 μE·m−2·sec−1 PPFD (PN1500) declined steadily in all treatments during seed growth. PN1500 and plant dark respiration, respectively, were reduced by 6.8 and 3.3 mg CO2·dm−2·hour−1 in defoliated compared to non‐defoliated plots. Soil CO2 efflux rates did not differ significantly (P < 0.05) between treatments. Differences in pod growth rates (7.6 and 9.21 g·m−2·day−1 and yields (434 and 502 g·m−2) between defoliated and non‐defoliated plots, respectively, were attributed to differences in canopy photosynthetic capacity. There was no apparent effect of defoliation on seed growth duration or seed abortion. Rather, yield reduction in defoliated plots was related primarily to slowing of the individual seed growth rate. Balance of carbon flux to seeds showed relationships between instantaneous canopy CO2 exchange measurements and sequential harvest data.
Embryological Analysis of Facultative Apomixis in Panicum maximum Jacq.1
Authors: Savidan Yves H. 
Published: July 2010

Eighty apomictic accessions of Guineagrass (Panicum maximum Jacq.) collected mainly in East Africa, and 80 apomictic hybrids from sexual ✕ apomictic crosses, were studied for their mode of reproduction. The objective was to determine to what extent percentage sexuality in facultative apomixis can be modified following hybridization. Apomictic accessions with a high percentage sexual reproduction were observed among biotypes from South Africa and the Antilles. Three of the hybrids also exhibited a high percentage of sexuality, while almost all the others appeared to be obligate or nearly obligate apomicts. The average percentage sexual reproduction observed in apomictic hybrids was 5.6 compared to 8.1 in apomictic accessions. Thus hybridization did not increase sexuality in apomicts of P.maximum.Embryological analyses appeared to be especially efficient and a rapid means for determining the mode of reproduction in P. maximum. However, because apomixis is essentially obligate or nearly obligate in this species, progeny tests are no less reliable than embryological analyses.Based on these and previous findings, there is no doubt that apomixis, although facultative, can be easily manipulated in P. maximum.
Selection Indices for the Improvement of Opaque‐2 Maize1
Authors: St. Martin S. K. , Loesch P. J. , Demopulos‐Rodriguez J. T. , Wiser W. J. 
Published: July 2010

The need to improve agronomic and protein and kernel quality characters in opaque‐2 maize (Zea mays L.) mandates consideration of multiple traits in selection. Data from genetic studies in an opaque‐2 maize synthetic were used to calculate selection indices for use in recurrent selection. Grain yield was considered the only trait having explicit economic value. Restricted indices were used to achieve satisfactory gains in kernel hardness, moisture content, and protein content and quality.The most important traits with respect to achieving the specified selection goals were yield, moisture content, kernel hardness, lysine content, kernel weight, and the degree of light transmission by kernels. Indices incorporating five traits were more efficient in that the addition of a sixth trait contributed very little to expected gains. The most effective combinations of traits for a recurrent selection scheme involving S1 testing were also the most effective for S2 testing and full‐sib testing.The degree to which gains predicted for an index were dependent on accurate estimates of the population parameters was considered. Indices having weights that implied reliance on indirect rather than direct selection response were not recommended.Substitution of single‐plant data for data from replicated progeny tests was considered in connection with each breeding scheme. The possibility of increasing the effective selection intensity, given that resources for replicated testing were fixed, by culling individual plants was investigated, but the use of individual plant data did not increase expected gain.A measure of subjective judgment on the part of the breeder is probably required for the successful application of selection indices to complex problems.
Heritabilities, Gains from Selection, and Genetic Correlations for Characteristics of Soybeans Grown in Two Row Spacings1
Authors: Weaver D. B. , Wilcox J. R. 
Published: July 2010

Heritabilities, gains from selection, and genetic correlations among maturity, lodging, height, and seed yield were calculated and compared for soybeans [Glycine max (L.) Merr.] in 30‐ and 76‐ cm row spacings over 2 years at West Lafayette, Ind. The primary objective was to determine if estimates of genotypic and environmental components of these characteristics that have been obtained in wide‐row spacings are applicable for selection, evaluation, and production in narrow‐row spacings. Experimental genotypes in both Maturity Groups II and III consisted of three adapted cultivars and 37 randomly selected F5 and F6 lines representing typical early generation breeding material.Heritability estimates and expected responses to selection were similar for both row spacings and all characteristics except seed yield. The absence of a year ✕ genotype interaction for seed yield in narrow rows for both maturity groups resulted in a higher hcritability estimate for yield in narrow than in wide rows. This suggests more efficient selection for seed yield in narrow‐row test plots when selection is based on only 1 year's evaluation. Genotype ✕ row spacing interactions for all characteristics were not significant, and genetic correlations between wide and narrow rows were approximately 1.0, suggesting that genotypes ranked similarly for all characteristics in both environments. It was concluded that there was no penalty for early generation selection and evaluation in wide‐row plots with later evaluation and production in narrow rows.
Agronomic and Bread‐Making Performance of Fertile Alloplasmic Wheats1
Authors: Kofoid K. D. , Maan S. S. 
Published: July 2010

The wild and cultivated relatives of common wheat (Triticum aestivum L.) that produce fertile alloplasmic lines may provide a large reservoir of cytoplasmic variability for this crop. To determine the effects of alien cytoplasms on agronomic and bread‐making quality performance, 14 alloplasmic lines, each with the nuclear genome of the hard red spring wheat cultivar ‘Selkirk’ and cytoplasm from a species of Triticum L., Alegilops L., or Haynaldia Schur., and the euplasmic control were evaluated at three locations in 1979. In general, the performance of the alloplasmic lines corresponded to the genomic similarity between the cytoplasm and nuclear doner species. Accordingly, lines with cytoplasm from Triticum species were superior to lines with cytoplasm from Aegilops species for days to head, grain yield, and kernels per spike. However, lines with cytoplasm from Aegilops species had more protein and better loaf volume than the Triticum cytoplasm lines.Among the alloplasmic lines, only days to head differed among the lines with cytoplasm from Triticum. The alloplasmic line with Ae. variabilis Eig cytoplasm was inferior to the average of all other lines with cytoplasm from Aegilops for most of the agronomic traits studied. Differences between lines with cytoplasm from D genome Aegilops species (Ae. squarrosa L., Ae. cylindrica Host and Ae. ventricosa Tausch), and those with cytoplasm from M genome Aegilops species (Ae. uniaristata Vis. and Ae. juvenalis (Thell.) Eig) were found only for days to head and loaf volume. These results indicate a closer relationship among the D and the M‐genome Aegilops species than between these species and Ae. variabilis.Since agronomic performance was reduced only by the cytoplasms of Ae. variabilis and H. villosa, the other male‐fertile cytoplasms should serve as useful sources to increase the cytoplasmic variability of common wheat.
Evaluation of Vigor Tests in Soybean Seeds: Relationship of Accelerated Aging, Cold, Sand Bench, and Speed of Germination Test to Field Performance1
Authors: Kulik Martin M. , Yaklich Robert W. 
Published: July 2010

Laboratory and greenhouse vigor tests and seed size determinations were performed on 144 and 81 seed lots of soybean [Glycinemax (L.) Merr.] in 1975 and 1976, respectively. These consisted each year of the accelerated aging, cold, and the sand bench test. In 1976, the speed of germination test was included.Results from these tests and seed weight determinations were compared with field emergence data obtained from these same seed lots at two locations (sandy vs. heavy soil) over three dates of planting each year. The accelerated aging, cold, sand bench, and speed of germination tests were significantly correlated with field emergence in both years, with many of the r values greater than 0.7.Data from vigor tests presented in this paper and in previous reports were used in computing coefficients of determination and linear regression coefficients for the estimation of final emergence. The coefficients of determination indicated that the estimation of final emergence for a group of seed lots within a particular year may be achieved by using the germination‐total live seedlings, from the standard towel, accelerated aging‐normal seedlings, accelerated aging‐total live seedlings, tetrazolium staining‐viable seeds, conductivity/g seed wt., sand bench emergence, cold test emergence and speed of germination‐4 day total tests. Linear regression coefficients were not consistent over years for some of the vigor tests. Those vigor tests with the most consistent linear regression coefficients are suggested for use when estimating potential field emergence over years. The vigor tests with the most consistent linear regression coefficients over years were the cold test emergence, tetrazolium staining‐viable seeds, accelerated aging‐normal seedlings and accelerated aging‐total live seedlings. None of the tests are recommended for predicting field emergence.
Tillering in Barley: Genotype, Row Spacing, and Seeding Rate Effects1
Authors: Simmons Steve R. , Rasmusson Donald C. , Wiersma John V. 
Published: July 2010

Production of tillers and their subsequent survival are important events in growth and development of barley (Hordeum vulgare L.) that affect the number of spikes produced per unit land area. Studies were conducted at St. Paul and Crookston, MN to evaluate tiller production, tiller mortality, and yield of 10 barley genotypes with different tillering capacities. In addition, these studies evaluated the influence of row spacing and seeding rate on tillering.The genotypes differed significantly in shoot and spike number. Shoot number for the highest tillering genotype was 42 to 71% greater than for the lowest, depending on the study, but the genotypes ranked consistently over years and locations. The high tillering genotypes tended to form tillers more frequently at the coleoptile node, in the axil of the third leaf, and from the primary tiller in the axil of the first leaf on the main shoot. In general, absolute shoot mortality (difference between maximum shoot number and spike number) was higher in the high tillering genotypes. Genotype M72‐269 was an exception to this generalization in having high shoot number and low shoot mortality.Row spacings of 7.5 and 15 cm had more shoots per unit area than the 30 cm spacing. However, narrower rows also had higher shoot mortality which led to similar spike numbers for the three row spacings. Higher seeding rates of 101 and 134 kg ha‐1 increased shoot number and spike number compared to the 67 kg ha‐1 rate. Changes in row spacing and seeding rate did not differentially affect shoot production or absolute shoot mortality among the genotypes.Grain yields of both low and high tillering genotypes were as high or higher than those of intermediate tillering cultivars. The extremely high and low tillering genotypes were not consistent in their yield performance at Crookston, suggesting a possible association between tillering capacity and yield stability. Small stem diameter and a tendency to lodge were characteristic of the high tillering genotypes. Identification of apparent genetic diversity for tiller mortality provides material for further study of the relationship between tiller mortality and yield.
Variability for Quality and Agronomic Traits in Forage Sorghum Hybrids1
Authors: Pedersen J. F. , Gorz H. J. , Haskins F. A. , Ross W. M. 
Published: July 2010

The variation among 49 F1 forage sorghum [Sorghum bicolor (L.) Moench] hybrids from a 7 ✕ 7 cross‐classified design was explored in 1979 and 1980 for the following traits: dry matter (DM), crude protein (CP), in vitro dry matter disappearance (IVDMD), neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL). Differences were found among hybrids for all traits. Parental means for males generally had a wider range of variation than for females. The means of hybrids involving the male parent, ‘White Collier’, were highest in IVDMD, and lowest in NDF, ADF, and ADL.IVDMD was the only trait that showed significant differences among hybrids averaged over both males and females. General combining ability (GCA) effects were more important than specific combining ability effects.Our results suggest that the most rapid way to improve forage sorghum quality would be by improving IVDMD. Significant differences among hybrids averaged over both male and female parents were shown for this trait; it was affected relatively little by year effects and exhibited high GCA effects.