scholarly journals Genotypic variation in cardinal temperatures and thermal time for germination and seedling emergence of pigeonpea [Cajanus cajan (L.) Millsp.]

2021 ◽  
pp. 1-12
Author(s):  
Sabampillai Mahendraraj ◽  
Marisa Collins ◽  
Yash Chauhan ◽  
Vincent Mellor ◽  
Rao C.N. Rachaputi
Keyword(s):  
Cajanus Cajan ◽  
Seedling Emergence ◽  
Genotypic Variation ◽  
Thermal Time ◽  
Cardinal Temperatures

Development in Cowpea (Vigna unguiculata). I. The Influence of Temperature on Seed Germination and Seedling Emergence

1996 ◽  
Vol 32 (1) ◽  
pp. 1-12 ◽  
Author(s):  
P. Q. Craufurd ◽  
R. H. Ellis ◽  
R. R. J. Summerfield ◽  
L. Menin
Keyword(s):  
Seed Germination ◽  
Vigna Unguiculata ◽  
Developmental Plasticity ◽  
Seedling Emergence ◽  
Genotypic Variation ◽  
Thermal Time ◽  
Influence Of Temperature ◽  
Influence Of Temperature On ◽  
Semi Arid

SUMMARYThe base (Tb), optimum (To) and ceiling (Tce) temperature for 50% seed germination and seedling emergence, and the thermal time at sub-optimal temperatures (θ1), were examined in experiments with a range of cowpea genotypes from different habitats and latitudes. There was substantial genotypic variation in seed germination for Tb and To, but not for Tce. There was no evidence that genotypes from semi-arid habitats had higher values of To or Tce, but estimates of Tb for seed germination were related to latitude and were highest in genotypes originating from close to the equator. The significance of these responses as a component of developmental plasticity in relation to the adaptation of cowpeas is discussed.

Cardinal temperatures and thermal time required foremergence of lenti (Lens culinaris Medik)

2017 ◽  
Author(s):  
Ali reza Safahani ◽  
Behnam Kamakar ◽  
Amir Nabizadeh
Keyword(s):  
Lens Culinaris ◽  
Seedling Emergence ◽  
Information Criterion ◽  
Optimization Method ◽  
Thermal Time ◽  
Coefficient Of Determination ◽  
Nonlinear Regression Models ◽  
Maximum Temperatures ◽  
Time Required ◽  
Cardinal Temperatures

The present study was performed to compare four nonlinear regression models (segmented, beta, beta modified, and dent-like) to describe the emergence rate–temperature relationships of six lentil (Lens culinaris Medik) cultivars at field experiment with a range of sowing dates, with the aim of identifying the cardinal temperatures and physiological days (i.e., number of days under optimum temperatures) required for seedling emergence. Models and statistical indices were calibrated using an iterative optimization method and their performance was compared by root mean square error (RMSD), coefficient of determination (R2) and corrected Akaike information criterion correction (AIC). The beta model was found to be the best model for predicting the response of lentil emergence to temperature, (R2= 0.99; RMSD= 0.005; AICc= -232.97). Based on the model outputs, the base, optimum, and maximum temperatures of seedling emergence were 4.5, 22.9, and 40 °C, respectively. The Six physiological days (equivalent to a thermal time of 94 °C days) were required from sowing to emergence

Corn Genotypic Variation Effects on Seedling Emergence and Leaf Appearance for Short-Season Areas

2001 ◽  
Vol 186 (4) ◽  
pp. 267-271 ◽  
Author(s):  
S. H. Begna ◽  
D. L. Smith ◽  
R. I. Hamilton ◽  
L. M. Dwyer ◽  
D. W. Stewart
Keyword(s):  
Seedling Emergence ◽  
Genotypic Variation ◽  
Short Season ◽  
Leaf Appearance

Plant development of triticale cv. Lasko at different sowing dates

1998 ◽  
Vol 130 (3) ◽  
pp. 297-306 ◽  
Author(s):  
R. E. L. NAYLOR ◽  
J. SU
Keyword(s):  
Stem Elongation ◽  
Seedling Emergence ◽  
Sowing Date ◽  
Thermal Time ◽  
Development Stages ◽  
Leaf Emergence ◽  
Sowing Dates ◽  
Time Requirements ◽  
Leaf Appearance ◽  
Double Ridge

The progress of leaf emergence, external morphology and apical development stages were recorded in sowings of triticale (cv. Lasko) made from February to November 1990 at Aberdeen (57° N). Leaf appearance and the number of primordia were related to thermal time (above a base of 0°C) except when photoperiods were <c. 11 h. The thermal time per phyllochron varied between leaves and the combined times for all the phyllochrons at a particular sowing accounted for the apparent response of average phyllochron to sowing date. The thermal time requirements for progression to the double ridge stage, terminal spikelet stage, onset of stem elongation and anthesis were similar except where photoperiods of <11 h occurred. The rate of grain primordium production was constant when photoperiod had been increasing at seedling emergence but the rate was reduced when the seedling experienced shortening photoperiods at emergence.

Seed-bed cultivations and sugar-beet seedling emergence

1989 ◽  
Vol 112 (2) ◽  
pp. 159-169 ◽  
Author(s):  
R. J. Gummerson
Keyword(s):  
Sugar Beet ◽  
Time Course ◽  
Seedling Emergence ◽  
Physical Characteristics ◽  
Thermal Time ◽  
Fine Aggregates ◽  
Soil Physical Characteristics

SummaryExperiments are described in which a range of seed beds was created in each of 5 years. The weather in these years produced wet, dry and capping seed-bed conditions. The time course of sugar-beet seedling emergence on each seed bed was recorded each year and the differences were considered in terms of soil physical characteristics: much of the year-to-year variation was accounted for by considering thermal time above 3 °C. The differences in emergence between seed beds were large only when conditions were dry, but in all years it was advantageous to level the seed bed in autumn or winter. Seed beds with a dense soil below the seed and fine aggregates above gave the most suitable conditions for rapid and successful emergence.

scholarly journals Evaluation of Chickpea (Cicer arietinum L.) Genotypes for Quality Seedlings

1970 ◽  
Vol 8 (2) ◽  
pp. 108-116
Author(s):  
Shahrina Akhtar ◽  
Jalal Uddin Ahmed ◽  
Abdul Hamid ◽  
Md Rafiqul Islam
Keyword(s):  
Biomass Production ◽  
Plant Biomass ◽  
Function Analysis ◽  
Dominant Role ◽  
Seedling Emergence ◽  
Genotypic Variation ◽  
Dry Weight ◽  
Total Biomass ◽  
Maximum Variance ◽  
Total Dry Weight

A study was conducted to evaluate 100 chickpea genotypes to explore their genetic diversity in respect of emergence and growth attributes. A high genotypic variation was observed in the characters studied. The highest positive correlation corresponded to the root mass and total plant biomass of the seedlings. Seedling biomass production was highly subjective to seedling vigor. Using discriminant function analysis, the first two functions contributed 46.2 and 39.0%, and altogether 85.2% of the variability among the genotypes. Function 1 was positively related to dry weight of root and total plants. The character with the greatest weight on function 2 was seedling emergence rate. The total dry weight of seedlings played the most dominant role in explaining the maximum variance in the genotypes. The genotypes were grouped into six clusters. Each cluster had specific seedling characteristics and the clusters 5 and 6 were closely related and clearly separated from clusters 1 and 4 for their higher amount of root and total biomass production, and vigorous seedlings, where as, the genotypes in cluster 2 and 3 were intermediate. The genotypes in cluster 5 followed by cluster 6 appeared to be important resources for selecting and developing chickpea variety. Keywords: Chickpea; genotypes; seedling; quality DOI: 10.3329/agric.v8i2.7584 The Agriculturists 8(2): 108-116 (2010)

Functional and quantitative analysis of seed thermal responses in prostrate knotweed (Polygonum aviculare) and common purslane (Portulaca oleracea)

Weed Science ◽  
1998 ◽  
Vol 46 (1) ◽  
pp. 83-90 ◽  
Author(s):  
B. C. Kruk ◽  
R. L. Benech-Arnold
Keyword(s):  
Quantitative Analysis ◽  
Seedling Emergence ◽  
Screening Method ◽  
Thermal Conditions ◽  
Thermal Time ◽  
Base Temperature ◽  
Emergence Period ◽  
Thermal Range ◽  
Polygonum Aviculare ◽  
Common Purslane

A screening method was used to characterize seed thermal responses of prostrate knotweed and common purslane, two important weeds invading wheat in the humid Pampa. Through this method, it was possible to detect thermal conditions that induce or break dormancy in both species. In addition, we were able to quantify changes in dormancy level in seed populations as a function of time of burial after dispersal, through changes in width of the thermal range within which germination can occur. Plotting the overlap of this thermal range and observed soil temperature throughout the year allowed the prediction of the seedling emergence period. This prediction was in agreement with observed seedling emergence in the field for both species, during 2 consecutive yr. From the analysis carried out under laboratory conditions, it was also possible to estimate required thermal time for germination of the nondormant fraction of the population and the base temperature above which thermal time is accumulated. The results obtained from this study are the basis for the formulation of seed germination models that predict not only the occurrence of seedling emergence in the field, but also the dynamics of germination within those periods.

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