scholarly journals Photosynthetic Light Response of Six Clonal Selections of the Sweet Potato Cultivar `Beauregard'

HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 605f-606
Author(s):  
Jeffrey T. Baker ◽  
Marvin L. Baker ◽  
D. Ron Earhart ◽  
Leonard M. Pike ◽  
Kil S. Yoo ◽  
...  
Keyword(s):  
Agricultural Research ◽  
Dark Respiration ◽  
Potato Cultivar ◽  
Light Response ◽  
Field Trials ◽  
Quality Characteristics ◽  
Parameter Estimates ◽  
Wide Range ◽  
Leaf Photosynthetic Rate ◽  
Extension Center

Eight individual potatoes, exhibiting a wide range of quality characteristics, were cloned at the Texas A&M Vegetable Improvement Center, College Station, Tex., in order to produce a large number of slips for field trials. Leaf photosynthetic light response for six of these clonal selections was determined during a greenhouse experiment conducted at the Texas A&M Univ. Agricultural Research and Extension Center at Overton, Tex. Photosynthesis data were fit to a rectangular hyperbola in order to estimate light saturated leaf photosynthetic rate (Amax), quantum efficiency (QE), and dark respiration rate (Rd). Significant differences (P ≥ 0.05) were detected in all three of these parameter estimates among the six clonal selections. Parameter estimates ranged from 23.4 to 28.8 μmol (CO2) m-2·s-1, 0.056 to 0.071 mol (CO2)/mol (photons), and –0.9 to –2.0 μmol (CO2) m-2·s-1 for Amax, QE, and Rd, respectively. However, these differences were not clearly related to quality characteristics determined for these clones in field trials.

Comparative Effect of Groundnut (Arachis hypogea l.) Genotypes on Yield and N Fixation in Sudan and Northern Guinea Savannahs of Nigeria

2019 ◽  
pp. 61-67
Keyword(s):  
Agricultural Research ◽  
Cropping Systems ◽  
Block Design ◽  
Dry Weight ◽  
Field Trials ◽  
Yield Potential ◽  
N Fixation ◽  
Maize Crop ◽  
Significant Interaction Effect ◽  
Pod Yield

Recognition of high yielding and nitrogen (N) fixing groundnut genotypes and desegregating them in the cereal-based cropping systems common in savannah regions will enhance food security and reduce the need for high N fertilizers hence, minimize the high cost and associated environmental consequences. Field trials were conducted during the 2015 growing season at the Research Farms of Bayero University Kano (BUK) and Institute for Agricultural Research (IAR), Ahmadu Bello University, Samaru-Zaria to assess the yield potential and Biolog- ical N fixation in 15 groundnut genotypes (ICG 4729, ICGV-IS 07823, ICGV-IS 07893, ICGV-IS 07908, ICGV- SM 07539, ICGV- SM 07599, ICGV-IS 09926, ICGV-IS 09932, ICGV-IS 09992, ICGV-IS 09994, SAMNUT-21, SAMNUT-22, SAMNUT-25, KAMPALA and KWANKWAS). The groundnut genotypes and reference Maize crop (SAMMAZ 29) were planted in a randomized complete block design in three replications. N difference method was used to estimate the amount of N fixed. The parameters determined were the number of nodules, nod- ule dry weight, shoot and root dry weights, pod, and haulm yield as well as N fixation. The nodule dry weight, BNF, haulm, and pod yield were statistically significant (P<0.01) concerning genotype and location. Similarly, their interac- tion effect was also highly significant. ICGV-IS 09926 recorded the highest nod- ule dry weight of 2.07mg /plant across the locations while ICGV-IS 09932 had the highest BNF value of 140.27Kg/ha. Additionally, KAMPALA had the high- est haulm yield, while ICGV-IS 07893 had the highest pod yield across the loca- tions with a significant interaction effect. The result shows that ICGV-IS 07893 and ICGV-IS 09932, as well as ICGV-IS 09994 and SAMNUT – 22, were the best genotypes concerning BNF, haulm and pod yield in the Northern Guinea and Sudan Savannahs of Nigeria respectively with the potential for a corresponding beneficial effect.

Interval of days required for determining efficient relations between climatic factors and cotton flower and boll production

2002 ◽  
Vol 82 (3) ◽  
pp. 499-506 ◽  
Author(s):  
Zakaria M Sawan ◽  
Louis I Hanna ◽  
Willis L McCuistion
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Surface Soil ◽  
Cultural Practices ◽  
Agricultural Research ◽  
Climatic Factors ◽  
Sunshine Duration ◽  
Field Trials ◽  
Cotton Production ◽  
Surface Soil Temperature

The cotton plant (Gossypium spp.) is sensitive to numerous environmental factors. This study was aimed at predicting effects of climatic factors grouped into convenient intervals (in days) on cotton flower and boll production compared with daily observations. Two uniformity field trials using the cotton (G. barbadense L.) cv. Giza 75 were conducted in 1992 and 1993 at the Agricultural Research Center, Giza, Egypt. Randomly chosen plants were used to record daily numbers of flowers and bolls during the reproductive stage (60 days). During this period, daily air temperature, temperature magnitude, evaporation, surface soil temperature, sunshine duration, humidity, and wind speed were recorded. Data, grouped into intervals of 2, 3, 4, 5, 6, and 10 d, were correlated with cotton production variables using regression analysis. Evaporation was found to be the most important climatic variable affecting flower and boll production, followed by humidity and sunshine duration. The least important variables were surface soil temperature at 0600 and minimum air temperature. The 5-d interval was found to provide the best correlation with yield parameters. Applying appropriate cultural practices that minimize the deleterious effects of evaporation and humidity could lead to an important improvement in cotton yield in Egypt. Key words: Cotton, flower production, boll production, boll retention

Grain mineral density of bread and durum wheat landraces from geochemically diverse native soils

2018 ◽  
Vol 69 (4) ◽  
pp. 335 ◽  
Author(s):  
José Francisco Vázquez ◽  
Efraín Antonio Chacón ◽  
José María Carrillo ◽  
Elena Benavente
Keyword(s):  
Durum Wheat ◽  
Triticum Aestivum L ◽  
Field Trials ◽  
Mineral Elements ◽  
Small Scale ◽  
Mineral Density ◽  
Native Soil ◽  
Wide Range ◽  
Grain Zinc ◽  
Wheat Landraces

Future progress on the creation of wheat cultivars with high grain zinc (Zn) and iron (Fe) mineral density will depend on both the availability of suitable donor germplasm and the identification of genes or quantitative trait loci contributing to increase the accumulation of mineral elements in the wheat kernels. Multi-environment field trials were conducted to evaluate the grain Zn, Fe and protein concentration of 32 bread wheat (Triticum aestivum L.) and 20 durum wheat (T. turgidum L. var. durum) landraces locally adapted to soils covering a wide range of pH values and mineral composition. These landraces were selected after a preliminary, small-scale field trial that had analysed 425 Spanish local varieties. Analyses of variance demonstrated a significant effect of genotype on grain composition, and 16 wheat landraces with elevated grain Zn and/or Fe density across the environments were identified. These landraces rich in grain minerals represent valuable primary gene-pool parents for wheat biofortification. No pattern of native soil geochemical characteristics that could help to predict the success in collecting mineral-dense genotypes in a given area was found. Mapping populations derived from some pairs of grain-mineral-rich and -poor genotypes characterised in the study may facilitate the development of molecular markers to assist the selection of superior wheat genotypes.

scholarly journals In-field screening for host plant resistance to Delia radicum and Brevicoryne brassicae within selected rapeseed cultivars and new interspecific hybrids

2020 ◽  
Vol 15 (1) ◽  
pp. 711-720
Author(s):  
Janetta Niemann ◽  
Justyna Szwarc ◽  
Jan Bocianowski ◽  
Dorota Weigt ◽  
Marek Mrówczyński
Keyword(s):  
Life Sciences ◽  
Field Trials ◽  
Brevicoryne Brassicae ◽  
Delia Radicum ◽  
Sources Of Resistance ◽  
Cabbage Aphid ◽  
Hybrid Combination ◽  
Resistance To Insects ◽  
Wide Range ◽  
High Level

AbstractRapeseed (Brassica napus) can be attacked by a wide range of pests, for example, cabbage root fly (Delia radicum) and cabbage aphid (Brevicoryne brassicae). One of the best methods of pest management is breeding for insect resistance in rapeseed. Wild genotypes of Brassicaceae and rapeseed cultivars can be used as a source of resistance. In 2017, 2018, and 2019, field trials were performed to assess the level of resistance to D. radicum and B. brassicae within 53 registered rapeseed cultivars and 31 interspecific hybrid combinations originating from the resources of the Department of Genetics and Plant Breeding of Poznań University of Life Sciences (PULS). The level of resistance varied among genotypes and years. Only one hybrid combination and two B. napus cultivars maintained high level of resistance in all tested years, i.e., B. napus cv. Jet Neuf × B. carinata – PI 649096, Galileus, and Markolo. The results of this research indicate that resistance to insects is present in Brassicaceae family and can be transferred to rapeseed cultivars. The importance of continuous improvement of rapeseed pest resistance and the search for new sources of resistance is discussed; furthermore, plans for future investigations are presented.

scholarly journals Omitted Variable Bias in GLMs of Neural Spiking Activity

2018 ◽  
Vol 30 (12) ◽  
pp. 3227-3258 ◽  
Author(s):  
Ian H. Stevenson
Keyword(s):  
Neural Activity ◽  
Single Neuron ◽  
Linear Models ◽  
Theory And Practice ◽  
Parameter Estimates ◽  
Omitted Variables ◽  
History Effects ◽  
Omitted Variable Bias ◽  
Wide Range ◽  
Variable Bias

Generalized linear models (GLMs) have a wide range of applications in systems neuroscience describing the encoding of stimulus and behavioral variables, as well as the dynamics of single neurons. However, in any given experiment, many variables that have an impact on neural activity are not observed or not modeled. Here we demonstrate, in both theory and practice, how these omitted variables can result in biased parameter estimates for the effects that are included. In three case studies, we estimate tuning functions for common experiments in motor cortex, hippocampus, and visual cortex. We find that including traditionally omitted variables changes estimates of the original parameters and that modulation originally attributed to one variable is reduced after new variables are included. In GLMs describing single-neuron dynamics, we then demonstrate how postspike history effects can also be biased by omitted variables. Here we find that omitted variable bias can lead to mistaken conclusions about the stability of single-neuron firing. Omitted variable bias can appear in any model with confounders—where omitted variables modulate neural activity and the effects of the omitted variables covary with the included effects. Understanding how and to what extent omitted variable bias affects parameter estimates is likely to be important for interpreting the parameters and predictions of many neural encoding models.

scholarly journals Economics of a Hairy Vetch Mulch System for Producing Fresh-market Tomatoes in the Mid-Atlantic Region

1995 ◽  
Vol 120 (5) ◽  
pp. 854-860 ◽  
Author(s):  
Terry C. Kelly' ◽  
Yao-Chi Lu ◽  
Aref A. Abdul-Baki ◽  
John R. Teasdale
Keyword(s):  
Agricultural Research ◽  
Field Trials ◽  
Economic Benefits ◽  
Environmental Benefits ◽  
Attractive Alternative ◽  
Hairy Vetch ◽  
Fresh Market ◽  
Organic Mulch ◽  
Budget Analysis ◽  
Tomato Field

Concern for the environment has focussed attention on the need for environmentally sound, yet economically profitable, farming practices. A hairy vetch (Vicia villosa L. Roth.) organic mulch system for fresh-market tomato (Lycopersicon esculentum Mill.) production provides environmental benefits by enhancing the soil and reducing the need for fertilizer and herbicide inputs and is more profitable than conventional practices. Tomato field trials over 3 years at the Beltsville (Md.) Agricultural Research Center compared the hairy vetch mulch system with black polyethylene mulch and bare ground (no mulch). Using partial budget analysis in a farm context, the hairy vetch mulch treatment was more profitable in all years under all market and yield adjustment scenarios. The vetch mulch system also was the preferred system for a risk-averse grower, according to a safety-first criterion. The combination of environmental benefits and the economic benefits to the grower make the hairy vetch mulch system an attractive alternative for producing fresh-market tomatoes in the Mid-Atlantic and parts of northeastern United States.

scholarly journals International Real Estate Review

2013 ◽  
Vol 16 (3) ◽  
pp. 323-343
Author(s):  
Jian Chen ◽  
◽  
David H. Downs ◽  
Keyword(s):  
Tax Policy ◽  
Negative Impact ◽  
Supply And Demand ◽  
Property Tax ◽  
Reduced Form ◽  
Parameter Estimates ◽  
Marginal Effect ◽  
Tenure Choice ◽  
Real Property ◽  
Wide Range

This paper examines real property tax as a determinant of tenure choice. The analysis is conducted in two stages. First, parameter estimates for a reduced-form homeownership model are obtained through multivariate logistic regression on data drawn from the U.S. Survey of Income and Program Participation (SIPP). Second, data from the Chinese Household Income Project (CHIP) is used to obtain predicted homeownership for China by using the SIPP-based model. Actual and predicted values of homeownership in China are presented, and the marginal effect of property tax is computed. Overall, we find that tenure choice is significantly influenced by property tax, even after controlling for a wide range of supply and demand considerations. Furthermore, and in the case of China, we show that the negative impact of property tax on homeownership may be mitigated by corresponding ownership incentives (e.g., tax policy). To the best of our knowledge, this is the first paper to explicitly analyze property tax in this regard. Implications based on the empirical analysis are applicable to the evolution of property tax policy in China.

The CGIAR Virtual Library Bridging the Gap Between Agricultural Research and Worldwide Users

2009 ◽  
pp. 308-320
Author(s):  
Mila M. Ramos ◽  
Luz Marina Alvaré ◽  
Cecilia Ferreyra ◽  
Peter Shelton
Keyword(s):  
Information Retrieval ◽  
Strategic Alliance ◽  
Agricultural Research ◽  
Information Services ◽  
Research Institutions ◽  
Virtual Library ◽  
Regional Organizations ◽  
Research Results ◽  
Wide Range ◽  
Consultative Group

This chapter introduces the Consultative Group on International Agricultural Research (CGIAR) Virtual Library as a tool for linking researchers and agricultural research results. The CGIAR is a strategic alliance of countries, international and regional organizations, and private foundations supporting 15 international agricultural centers that work in partnership with national agricultural research institutions and societies. The research results generated are numerous and cover a wide range of subject fields. While these are properly documented, locating relevant and timely information across the system’s 15 centers is a long and tedious process as individual databases have to be searched. The CGIAR virtual library (CGVLibrary) project of the CGIAR Libraries and Information Services Consortium (CGIARLISC) was created in 2005 to address the difficulty of information retrieval across the various centers. It is now available via the WWW (http://vlibrary.cgiar.org/) and knowledge generated by the CGIAR can now be retrieved with a few mouse clicks.

Foliar Sprays to Control European Corn Borer in Spring and Fall Peppers, 1997

1998 ◽  
Vol 23 (1) ◽  
pp. 119-120
Author(s):  
John Speese ◽  
Brian A. Nault
Keyword(s):  
European Corn Borer ◽  
Agricultural Research ◽  
Corn Borer ◽  
Spring Crop ◽  
Harvest Dates ◽  
Plant Stand ◽  
Crop Harvest ◽  
Marketable Fruit ◽  
Extension Center ◽  
Plant Basis

Abstract Peppers were transplanted on 23 May (spring crop) and 1 Aug (fall crop) at the Eastern Shore Agricultural Research and Extension Center, Painter, VA. Each plot consisted of two 20-ft-rows with 3-ft spacing between rows. Plots were separated from each other by an untreated guard row. Each treatment was replicated 4 times in a RCBD for both plantings. Sprays were applied with a propane-powered backpack sprayer using 6 flat-fan nozzles/2 rows and delivering 46 gal of spray/acre at 40 psi. Latron CS-7 was used with each application at 0.12% vol./vol. Weekly applications were made on both crops beginning when fruit was ≥2 inches in diameter. The spring crop was sprayed from 31 Jul-10 Sep (6 sprays), and the fall crop was sprayed from 17 Sep-8 Oct (4 sprays). To evaluate efficacy of the treatments, the market-sized fruit was harvested from the most uniform row and examined for ECB damage. The number and weight of undamaged (marketable) fruit, and the number of ECB damaged fruit, were recorded for each crop. Harvest dates are indicated in the tables. Plant stand counts were taken in all harvested rows, and yields and % damaged fruit were adjusted to a per plant basis.

scholarly journals Genetic variability, correlation and path analysis of exotic and local hybrid maize (Zea mays L.) genotypes

2020 ◽  
Vol 6 (1) ◽  
pp. 8-15
Author(s):  
Nlima Ahmed ◽  
Abul Kashem Chowdhury ◽  
Md Saleh Uddin ◽  
Md Mainul Islam Rashad
Keyword(s):  
Agricultural Research ◽  
Path Coefficient ◽  
Research Station ◽  
Positive Contribution ◽  
Genetic Advance ◽  
Lattice Design ◽  
Wide Range ◽  
Ear Height ◽  
Hybrid Maize ◽  
Number Of Seeds

The genetic parameters, characters association and path coefficient analysis between yield and yield components of 32 exotic and local hybrid maize genotypes were studied at Plant Breeding division, Regional Agricultural Research Station (RARS), Bangladesh Agricultural Research Institute (BARI), Rahmatpur, Barisahl during rabi 2015 to 2016, following Alpha Lattice Design with three replications. All the characters showed significant differences among the genotypes except cob length indicating their wide genetic variation. The highest genotypic co-efficient of variation (11.48) observed in yield and lowest (1.72) was found in days to maturity. All of the characters exhibited moderate to high heritability in broad sense (h2b) coupled with a wide range of genetic advance and genetic advance in percentage of mean. Heritability ranged from 19.21 to 86.79 for cob length and thousand seed weight, respectively. Yield had a significant positive correlation with cob length, cob diameter, number of seeds per cob and number of rows per cob. Days to tasseling and number of seeds per cob make highest positive contribution toward yield. While, days to silking and ear height had highest negative direct effect on yield. The results indicated that ear height, number of rows per cob, thousand seeds weight and number of seeds per cob could be considered as selection criteria in maize breeding program. Asian J. Med. Biol. Res. March 2020, 6(1): 8-15

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