Impact of Plant Spacing and Population on Yield for Single-Row Nonirrigated Peanuts (Arachis hypogaea L.)

2000 ◽  
Vol 27 (2) ◽  
pp. 52-56 ◽  
Author(s):  
D. A. Sternitzke ◽  
M. C. Lamb ◽  
J. I. Davidson ◽  
R. T. Barron ◽  
C. T. Bennet
Keyword(s):  
Field Experiments ◽  
Rate Of Change ◽  
Plant Spacing ◽  
Lower Yield ◽  
Arachis Hypogaea L ◽  
Average Plant ◽  
Relationship Of ◽  
The Relationship ◽  
Water Nutrients ◽  
Lower Population

Abstract Poor peanut emergence often results in lower yield and loss of revenue. Farmers attempting to recapture lost income sometimes lose even more by replanting because replant costs may exceed the benefits of added yield. The purpose of this study was to develop an empirical equation to predict peanut yield based on total emergence 21 d after planting and an estimate of yield for a full stand of peanuts. Field experiments were conducted in Terrell Co., Georgia during 1997 and 1998 for nonirrigated peanut (cv. Georgia Green) grown in an Americus sand (thermic Rhodic Paleudults). To mimic poor emergence and concomitant random plant spacing, rows within plots were thinned at random locations to attain populations of 4.4, 3.3, 2.6, 2.1, and 1.6 plants/m-row. Control plots were not thinned and total emergence was approximately 12.7 plants/m-row. As total emergence and population decreased, yield also decreased whereas pod mass per plant increased. This increase was likely attributed to a reduction in competition from adjacent peanut plants for water, nutrients, and light. Higher population treatments had smaller pod mass/plant and greater overall yield than lower population treatments with higher pod mass/plant. Random plant-to-plant spacing associated with poor emergence was used to predict pod mass/plant as a function of average plant spacing. Results from this research established models defining the relationship of the rate of change of pod mass per plant with average plant spacing and provided a new method of predicting yield in the event of poor emergence.

scholarly journals Effect of Three Ca Sources Applied On Peanuts I. Productivity and Seed Quality1

1980 ◽  
Vol 7 (1) ◽  
pp. 19-25 ◽  
Author(s):  
D. L. Hallock ◽  
A. H. Allison
Keyword(s):  
Crop Yields ◽  
Relative Effectiveness ◽  
Correlation Coefficients ◽  
Early Flowering ◽  
Lower Yield ◽  
Flowering Stage ◽  
Arachis Hypogaea L ◽  
Dry Conditions ◽  
Increase Productivity ◽  
The Relationship

Abstract The relative effectiveness of United States Gypsum granular 420 Landplaster Bulk (420-Bulk) and Texasgulf Gypsum (Tg Gypsum) were compared with finely ground anhydrite (Bagged-LP) as sources of supplemental Ca for Florigiant peanuts (Arachis hypogaea L.). Treatments included the above sources at rates of 605 kg/ha banded (61 cm) or 907 kg/ha broadcast (91-cm wide rows) of CaSO4 equivalent per unit area covered (double these rates of 420-Bulk and Bagged-LP also were applied in 1977). Times of application were planting, planting + ca 30 days, and early flowering stage. The experiments were located on Kenansville lfs (Arenic Hapludult) in 1977 and on Rumford lfs (Typic Hapludult) in 1978. The Ca treatments increased crop yields from 360 to 1,200 kg/ha and crop value (yield × price) from $343 to $889/ha over the check in 1977. Slightly lower yield increases were obtained in 1978 when dry conditions prevailed during fruit maturation. Kernel size grades were improved markedly by all Ca treatments in 1977. There was a definite trend both years (significant in 1978) toward higher productivity when the Ca sources were applied at the early flowering stage compared to earlier applications. No difference was noted between methods of application of Bagged-LP or Tg Gypsum in 1978. Double rates of Bagged-LP or 420-Bulk in 1977 did not increase productivity over the low rates. A single application of Bagged-LP was as effective as split applications in the 1978 test. Germinability of seed in 1977 averaged 85% or higher for all Ca treatments. Seed germination in 1978 averaged 75%, 69% and 74% in plots where Tg Gypsum, 420-Bulk or Bagged-LP was applied, respectively. Germination was lowest in the check plots both years. Germinability and seed-Ca contents were significantly higher in 1978 when the Ca sources were applied at the early flowering stage (ca July 1) than 15 days earlier. Seed-Ca contents both years and K contents in 1978 were significantly correlated with germinability. The correlation coefficients were only 0.4 in each case and the relationship was negative for K. In general, 420-Bulk, Tg Gypsum, or Bagged-LP were equally effective sources of supplemental Ca for peanuts. However, when fruit mature under very dry conditions 420-Bulk may be somewhat inferior to the other Ca sources especially when applied before early flowering.

scholarly journals Interactions Between Chill-Hours and Degree-Days Affect Carpogenic Germination in Monilinia vaccinii-corymbosi

2001 ◽  
Vol 91 (1) ◽  
pp. 77-83 ◽  
Author(s):  
H. Scherm ◽  
A. T. Savelle ◽  
P. L. Pusey
Keyword(s):  
Laboratory Experiments ◽  
Field Experiments ◽  
Degree Days ◽  
Carpogenic Germination ◽  
Conditioning Period ◽  
Low Degree ◽  
Heating Degree Days ◽  
Relationship Of ◽  
High Degree ◽  
The Relationship

The relationship of cumulative chill-hours (hours with a mean temperature <7.2°C) and heating degree-days (base 7.2°C) to carpogenic germination of pseudosclerotia of Monilinia vaccinii-corymbosi, which causes mummy berry disease of blueberry, was investigated. In two laboratory experiments, pseudosclerotia collected from rabbiteye blueberry in Georgia were conditioned at 5 to 6°C for 26 to 1,378 h prior to placement in conditions favorable for germination and apothecium development. The number of chill-hours accumulated during the conditioning period affected the subsequent proportion of pseudosclerotia that germinated and produced apothecia, with the greatest incidence of carpogenic germination occurring after intermediate levels of chilling (≈700 chill-hours). The minimum chilling requirement for germination and apothecium production was considerably lower than that reported previously for pseudo-sclerotia from highbush blueberry in northern production regions. The rate of carpogenic germination was strongly affected by interactions between the accumulation of chill-hours and degree-days during the conditioning and germination periods; pseudosclerotia exposed to prolonged chilling periods, once transferred to suitable conditions, germinated and produced apothecia more rapidly (after fewer degree-days had accumulated) than those exposed to shorter chilling periods. Thus, pseudosclerotia of M. vaccinii-corymbosi are adapted to germinate carpogenically following cold winters (high chill-hours, low degree-days) as well as warm winters (low chill-hours, high degree-days). Results were validated in a combined field-laboratory experiment in which pseudosclerotia that had received various levels of natural chilling were allowed to germinate in controlled conditions in the laboratory, and in two field experiments in which pseudosclerotia were exposed to natural chilling and germination conditions. A simple model describing the timing of apothecium emergence in relation to cumulative chill-hours and degree-days was developed based on the experiments. The model should be useful for better timing of field scouting programs for apothecia to aid in management of primary infection by M. vaccinii-corymbosi.

An improvement to the ANN-enhanced flow rating method

2021 ◽  
Author(s):  
Bernhard Schmid
Keyword(s):  
Neural Network ◽  
Electrical Conductivity ◽  
Water Resources ◽  
Flow Rate ◽  
Major Ions ◽  
Rate Of Change ◽  
Data Set ◽  
Input Variables ◽  
Relationship Of ◽  
The Relationship

&lt;p&gt;The work reported here builds upon a previous pilot study by the author on ANN-enhanced flow rating (Schmid, 2020), which explored the use of electrical conductivity (EC) in addition to stage to obtain &amp;#8216;better&amp;#8217;, i.e. more accurate and robust, estimates of streamflow. The inclusion of EC has an advantage, when the relationship of EC versus flow rate is not chemostatic in character. In the majority of cases, EC is, indeed, not chemostatic, but tends to decrease with increasing discharge (so-called dilution behaviour), as reported by e.g. Moatar et al. (2017), Weijs et al. (2013) and Tunqui Neira et al.(2020). This is also in line with this author&amp;#8217;s experience.&lt;/p&gt;&lt;p&gt;The research presented here takes the neural network based approach one major step further and incorporates the temporal rate of change in stage and the direction of change in EC among the input variables (which, thus, comprise stage, EC, change in stage and direction of change in EC). Consequently, there are now 4 input variables in total employed as predictors of flow rate. Information on the temporal changes in both flow rate and EC helps the Artificial Neural Network (ANN) characterize hysteretic behaviour, with EC assuming different values for falling and rising flow rate, respectively, as described, for instance, by Singley et al. (2017).&lt;/p&gt;&lt;p&gt;The ANN employed is of the Multilayer Perceptron (MLP) type, with stage, EC, change in stage and direction of change in EC of the M&amp;#246;dling data set (Schmid, 2020) as input variables. Summarising the stream characteristics, the M&amp;#246;dling brook can be described as a small Austrian stream with a catchment of fairly mixed composition (forests, agricultural and urbanized areas). The relationship of EC versus flow reflects dilution behaviour. Neural network configuration 4-5-1 (the 4 input variables mentioned above, 5 hidden nodes and discharge as the single output) with learning rate 0.05 and momentum 0.15 was found to perform best, with testing average RMSE (root mean square error) of the scaled output after 100,000 epochs amounting to 0.0138 as compared to 0.0216 for the (best performing) 2-5-1 MLP with stage and EC as inputs only. &amp;#160;&amp;#160;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;References&lt;/p&gt;&lt;p&gt;Moatar, F., Abbott, B.W., Minaudo, C., Curie, F. and Pinay, G.: Elemental properties, hydrology, and biology interact to shape concentration-discharge curves for carbon, nutrients, sediment and major ions. Water Resources Res., 53, 1270-1287, 2017.&lt;/p&gt;&lt;p&gt;Schmid, B.H.: Enhanced flow rating using neural networks with water stage and electrical conductivity as predictors. EGU2020-1804, EGU General Assembly 2020.&lt;/p&gt;&lt;p&gt;Singley, J.G., Wlostowski, A.N., Bergstrom, A.J., Sokol, E.R., Torrens, C.L., Jaros, C., Wilson, C.,E., Hendrickson, P.J. and Gooseff, M.N.: Characterizing hyporheic exchange processes using high-frequency electrical conductivity-discharge relationships on subhourly to interannual timescales. Water Resources Res. 53, 4124-4141, 2017.&lt;/p&gt;&lt;p&gt;Tunqui Neira, J.M., Andr&amp;#233;assian, V., Tallec, G. and Mouchel, J.-M.: A two-sided affine power scaling relationship to represent the concentration-discharge relationship. Hydrol. Earth Syst. Sci. 24, 1823-1830, 2020.&lt;/p&gt;&lt;p&gt;Weijs, S.V., Mutzner, R. and Parlange, M.B.: Could electrical conductivity replace water level in rating curves for alpine streams? Water Resources Research 49, 343-351, 2013.&lt;/p&gt;

The Relationship of Extraversion and Neuroticism to the Eeg

1971 ◽  
Vol 119 (553) ◽  
pp. 667-670 ◽  
Author(s):  
J. P. R. Young ◽  
M. H. Lader ◽  
G. W. Fenton
Keyword(s):  
Significant Interaction ◽  
Inverse Relationship ◽  
Evoked Potential ◽  
Rate Of Change ◽  
Automatic Frequency ◽  
Alpha Frequency ◽  
Relationship Of ◽  
Low Amplitude ◽  
The Relationship ◽  
Potential Waveform

In a recent series of investigations significant but conflicting relationships have been claimed between the two personality dimensions extraversion (E) and neuroticism (N) and certain spontaneous and induced features of the normal EEG. Savage (1964), using alpha abundance data from automatic frequency analysis, demonstrated a significant positive correlation between extraversion and high alpha amplitude. Extraversion has been similarly related to the amplitude of the averaged evoked potential waveform (Shagass and Schwartz, 1965). However, in an investigation by Broadhurst and Glass (1969) both alpha amplitude and prevalence bore an inverse relationship to E scores; extraversion was significantly associated with the rate of change of potential of the EEG, as was neuroticism with the alpha frequency. More recently, Winteret al. (1971) could find no direct relationship between extraversion and EEG amplitude, though there was a tendency for low amplitude activity to be associated with high neuroticism scores. The findings were interpreted as showing a significant interaction between the variables measured, the relationship of extraversion and amplitude varying according to the neuroticism score.

Effect of soil temperature during seed filling period on oleic/linoleic ratio, tocopherols and sugar contents in peanut kernels

2020 ◽  
Vol 71 (3) ◽  
pp. 369
Author(s):  
R. J. Haro ◽  
J. L. Dardanelli ◽  
M. J. Martínez
Keyword(s):  
Soil Temperature ◽  
Field Experiments ◽  
Linear Models ◽  
Positive Association ◽  
Seed Filling ◽  
Growth Environment ◽  
Sowing Dates ◽  
Relationship Of ◽  
The Relationship

The relationship of chemical quality of peanut seed with the soil temperature (ST) has received little attention. The aim of this work was to determine the effects of ST in the seed growth environment, during the seed filling period, on the oleic/linoleic acid (O/L) ratio, alpha, beta, gamma, delta tocopherols and the sum of them (TT), fructose, glucose and sucrose and the sum of them (FGS), contents in peanut kernels. Field experiments included cultivars (Florman and ASEM), water regimes (irrigated and water stress), sowing dates and alteration of ST. The response of O/L ratio to ST fitted a linear model, where the O/L ratio increased while ST increased. Mean O/L ratios were 1.31 for ASEM and 1.20 for Florman. The TT mean concentration was similar for both genotypes (478 ppm). A positive association between α-tocopherol (the main source of vitamin E) and ST, and a negative association between δ and α tocopherols were detected. The responses of FGS and sucrose to ST fitted linear models, where increments in ST showed decreases in FGS and sucrose concentrations. However, the decrease rates of FGS and sucrose in ASEM were three times lower than in Florman. The results showed that ST affected the chemical composition of peanut kernels, which mainly determines the shelf life and flavor of both genotypes differentially.

Estimation of Critical Period of Weed Control

Weed Science ◽  
1996 ◽  
Vol 44 (2) ◽  
pp. 273-283 ◽  
Author(s):  
M. Singh ◽  
M. C. Saxena ◽  
B. E. Abu-Irmaileh ◽  
S. A. Al-Thahabi ◽  
N. I. Haddad
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Field Experiments ◽  
Control Strategies ◽  
Maximum Yield ◽  
Logistic Function ◽  
Weed Infestation ◽  
Using Data ◽  
Relationship Of ◽  
The Relationship

An estimation of the critical period of weed control is helpful in formulating appropriate weed-control strategies. A regression approach is presented to estimate the thresholds of critical period of weed control and time of equal interference (or time of onset of competition). In this approach, yields were either a linear or logistic function of the duration of weed-free and weed-infested periods. Confidence intervals of the thresholds of critical period and time of equal interference were determined for the linear model. An approximation to the standard error of critical period and associated confidence interval were given for any general form of the model. The method was applied to estimate the critical period of weed control in rainfed lentil using data from four field experiments conducted in Jordan. The relationship of yield with the duration of weed-free period was described by a linear function, whereas the relationship with the duration of weed-infested period showed a better fit with a logistic function. To maintain 90% of maximum seed yield, the maximum time allowed to let weeds grow after the crop emergence varied over locations from 4.8 to 5.8 wk. The same level could be achieved if the crop is kept free of weeds from its emergence until 12.1 to 14.1 wk; while the time when the same amount of yield would be achieved under both approaches varied from 7.7 to 9.3 wk after crop emergence. For straw yield, the time to get 90% of the maximum yield could vary over location from a maximum of 4.5 to 8.0 wk under weed-infestation and from at least 11.5 to 13.5 wk when weed-free. The time to achieve the same amount of straw under two systems of competition varied from 6.5 to 9.9 wk after crop emergence. One of the four experiments showed a longer critical period than the others for seed and straw yields.

Effects of temperature and leaf wetness duration on infection of pear leaves by Venturia pirina

2000 ◽  
Vol 51 (1) ◽  
pp. 97 ◽  
Author(s):  
O. N. Villalta ◽  
W. S. Washington ◽  
G. M. Rimmington ◽  
P. A. Taylor
Keyword(s):  
Disease Severity ◽  
Field Experiments ◽  
Leaf Wetness ◽  
Leaf Wetness Duration ◽  
Controlled Conditions ◽  
Pyrus Communis L ◽  
Venturia Pirina ◽  
Effects Of Temperature ◽  
Relationship Of ◽  
The Relationship

The effects of temperature and wetness duration on the infection of pear leaves (Pyrus communis L.) by Venturia pirina were studied by inoculating plants with ascospores and conidia under controlled conditions and in the field. Under controlled inoculations, minimum wetness durations that lead to leaf infections by ascospores were 27, 15, 13, 11, 10, 9, and 9 h at 4, 8, 10, 12, 15, 20, and 25°C, respectively. In parallel inoculations with conidia, the minimum wetness durations that lead to leaf infections were similar to ascospores at temperatures between 12°C and 25°C, but at lower temperatures (4, 8, 10°C), conidia infected leaves only after an additional 2 h of leaf wetness. The relationship between minimum wetness times and temperature was best described using an exponential regression. In field experiments, leaf infection on plants inoculated with ascospores and conidia under various naturally occurring wetness and temperature conditions was in close agreement with those under controlled conditions. Disease severity (percent of leaf area infected) increased with increasing leaf wetness duration at all temperatures. The optimum temperature for infection was 20°C. Analysis of variance with orthogonal polynomial contrasts was used to define the relationship of the angular transformation of disease severity to temperature and leaf wetness duration.

Wild Oat (Avena fatua) and Spring Barley (Hordeum vulgare) Density Affect Spring Barley Grain Yield

1991 ◽  
Vol 5 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Richard M. Evans ◽  
Donald C. Thill ◽  
Lawrence Tapia ◽  
Bahman Shafii ◽  
Joan M. Lish
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Spring Barley ◽  
Barley Grain ◽  
Seed Rain ◽  
Wild Oat ◽  
Asymptotic Type ◽  
Oat Biomass ◽  
Relationship Of ◽  
The Relationship

Addition series field experiments were conducted near Moscow, ID, in 1987 and 1988 to determine the relative aggressiveness of spring barley and wild oat and to determine the effect of barley and wild oat density and proportion on barley grain yield and wild oat seed rain. Regression analysis was used to describe the relationship of the aboveground biomass and grain yield to species density. Barley was more aggressive than wild oat. Barley biomass was affected most by intraspecific competition, while wild oat biomass was affected most by interspecific competition. Barley aggressiveness changed little throughout the growing season. Wild oat aggressiveness varied but was always less than barley aggressiveness. Increasing wild oat density had a negative, asymptotic-type effect on barley grain yield at all barley densities. However, the effect of wild oat was greatest at the lower density of barley. Increasing barley density decreased wild oat seed rain.

scholarly journals Non-linear Relationships Between Density and Demographic Traits of Aedes

2021 ◽  
Author(s):  
Logan A. Sauers ◽  
Kelsey E. Hawes ◽  
Steven A. Juliano
Keyword(s):  
Population Growth ◽  
Empirical Relationship ◽  
Initial Density ◽  
Rate Of Change ◽  
Adult Size ◽  
Linear Relationships ◽  
Non Linear ◽  
Per Capita ◽  
Relationship Of ◽  
The Relationship

Abstract Understanding the relationship of population dynamics to density is central to many ecological investigations. Despite the importance of density-dependence in determining population growth, the empirical relationship between density and per capita growth remains understudied in most systems and is often assumed to be linear. In experimental studies of interspecific competition, investigators often evaluate the predicted outcomes by assuming such linear relationships, fitting linear functions, and estimating parameters of competition models. In this paper, we tested experimentally the shape of the relationship between estimated population rate of change and initial density using laboratory-reared populations of three mosquito species. We estimated per capita growth rate for these experimental populations over a thirty-fold range of larval densities at a standard resource abundance. We then compared fits of linear models and several different nonlinear models for the relationship of estimated rate of change and density. We find that that the relationship between density and per capita growth is strongly non-linear in all three mosquitoes. Components of population growth (survivorship, development time, adult size) are also nonlinearly related to initial density. The causes and consequences of this nonlinearity are likely to be important issues for population and community ecology.

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