View source: R/EmergenceRateIndex.R
EmergenceRateIndex | R Documentation |
Compute the Emergence rate index or Germination rate index according to
shmueli_emergence_1971;textualgerminationmetrics and it's modification by \insertCitede_santana_alise_2004;textualgerminationmetrics \insertCiteranal_how_2006germinationmetrics;
bilbro_soil_1982;textualgerminationmetrics; and
fakorede_relation_1980;textualgerminationmetrics, \insertCitefakorede_variability_1981;textualgerminationmetrics, and \insertCitefakorede_heterotic_1983;textualgerminationmetrics.
EmergenceRateIndex(
germ.counts,
intervals,
partial = TRUE,
total.seeds = NULL,
method = c("shmueligoldberg", "sgsantanaranal", "bilbrowanjura", "fakorede")
)
germ.counts |
Germination counts at each time interval. Can be partial
or cumulative as specified in the argument |
intervals |
The time intervals. |
partial |
logical. If |
total.seeds |
Total number of seeds. |
method |
The method to be used. Either |
The value of the Emergence rate index with the units according to
method
as follows.
shmueligoldberg |
\mjseqn\mathrm count |
sgsantanaranal |
\mjseqn\mathrm no \, unit |
bilbrowanjura |
\mjseqn\mathrm count \, time^-1 |
fakorede |
\mjseqn time \, \mathrmcount^-1 |
Several germination indices are referred to as Emergence rate Index (\mjseqnERI).
With argument method
specified as "shmueligoldberg"
\mjseqnERI is estimated as follows.
ERI = \sum_i=i_0^k-1N_i(k-i)
Where, \mjseqnN_i is the number of seeds germinated in the \mjseqnith time interval (not the accumulated number, but the number corresponding to the \mjseqnith interval), \mjseqni_0 is the time interval when emergence/germination started, and \mjseqnk is the total number of time intervals.
A modification for the same was suggested by
\insertCitede_santana_alise_2004;textualgerminationmetrics
\insertCiteranal_how_2006germinationmetrics and is estimated by
dividing Emergence rate index (\mjseqnERI) by total number of emerged
seedlings (or germinated seeds) as follows with argument method
specified as "sgsantanaranal"
).
ERI_mod = \frac\sum_i=i_0^k-1N_i(k-i)N_g = \fracERIN_g
Where, \mjseqnN_g is the total number of germinated seeds at the end of the test, \mjseqnN_i is the number of seeds germinated in the \mjseqnith time interval (not the accumulated number, but the number corresponding to the \mjseqnith interval), \mjseqni_0 is the time interval when emergence/germination started, and \mjseqnk is the total number of time intervals.
With argument method
specified as "bilbrowanjura"
\mjseqnERI is the estimated as follows.
ERI = \frac\sum_i=1^kN_i\overlineT = \fracN_g\overlineT
Where, \mjseqnN_g is the total number of germinated seeds at the end of the test, \mjseqnN_i is the number of seeds germinated in the \mjseqnith time interval (not the accumulated number, but the number corresponding to the \mjseqnith interval), and \mjseqn\overlineT is the mean germination time or mean emergence time.
With argument method
specified as "fakorede"
\mjseqnERI is
the estimated as follows.
ERI = \frac\overlineTFGP/100
Where, \mjseqn\overlineT is the Mean germination time and \mjseqnFGP is the final germination time.
Apart from the above the above, the name Emergence
rate index (\mjseqnERI) has also been used to for the mathematical
expressions for Speed of germination
(GermSpeed
)
\insertCiteallan_seedling_1962,erbach_tillage_1982germinationmetrics,
Timson's index (TimsonsIndex
)
\insertCitechaudhary_effect_1970germinationmetrics,
and George's index
(GermRateGeorge
)
\insertCitechopra_effect_1980germinationmetrics.
GermSpeed
,
TimsonsIndex
,
GermRateGeorge
x <- c(0, 0, 0, 0, 4, 17, 10, 7, 1, 0, 1, 0, 0, 0)
y <- c(0, 0, 0, 0, 4, 21, 31, 38, 39, 39, 40, 40, 40, 40)
int <- 1:length(x)
# From partial germination counts
#----------------------------------------------------------------------------
EmergenceRateIndex(germ.counts = x, intervals = int)
EmergenceRateIndex(germ.counts = x, intervals = int,
method = "shmueligoldberg")
EmergenceRateIndex(germ.counts = x, intervals = int,
method = "sgsantanaranal")
EmergenceRateIndex(germ.counts = x, intervals = int,
method = "bilbrowanjura")
EmergenceRateIndex(germ.counts = x, intervals = int,
total.seeds = 50, method = "fakorede")
# From cumulative germination counts
#----------------------------------------------------------------------------
EmergenceRateIndex(germ.counts = y, intervals = int, partial = FALSE)
EmergenceRateIndex(germ.counts = y, intervals = int, partial = FALSE,
method = "shmueligoldberg")
EmergenceRateIndex(germ.counts = y, intervals = int, partial = FALSE,
method = "sgsantanaranal")
EmergenceRateIndex(germ.counts = y, intervals = int, partial = FALSE,
method = "bilbrowanjura")
EmergenceRateIndex(germ.counts = y, intervals = int, partial = FALSE,
total.seeds = 50, method = "fakorede")
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