Description Usage Arguments Value Details References See Also Examples
View source: R/EmergenceRateIndex.R
Compute the Emergence rate index or Germination rate index according to
shmueliEmergenceEarlyGrowth1971;textualgerminationmetrics and it's modification by \insertCitede_santana_alise_2004;textualgerminationmetrics \insertCiteranal_how_2006germinationmetrics;
bilbroSoilCrustsCotton1982;textualgerminationmetrics; and
fakoredeRelationSeedlingVigor1980;textualgerminationmetrics, \insertCitefakoredeVariabilitySeedlingVigour1981;textualgerminationmetrics, and \insertCitefakoredeHeteroticEffectsAssociation1983;textualgerminationmetrics.
1 2 3 4 5 6 7  EmergenceRateIndex(
germ.counts,
intervals,
partial = TRUE,
total.seeds = NULL,
method = c("melville", "melvillesantanaranal", "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.
Several germination indices are referred to as Emergence rate Index (\mjseqnERI).
It is estimated as follows.
\mjsdeqnERI = \sum_i=i_0^k1N_i(ki)
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.
\mjsdeqnERI_mod = \frac\sum_i=i_0^k1N_i(ki)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.
It is the estimated as follows.
\mjsdeqnERI = \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.
It is estimated as follows.
\mjsdeqnERI = \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,erbachTillageContinuousCorn1982germinationmetrics,
Timson's index (TimsonsIndex
)
\insertCitechaudharyEffectTemperatureAssociated1970germinationmetrics,
and George's index
(GermRateGeorge
)
\insertCitechopraEffectSoilTemperature1980germinationmetrics.
GermSpeed
,
TimsonsIndex
,
GermRateGeorge
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27  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 = "melville")
EmergenceRateIndex(germ.counts = x, intervals = int,
method = "melvillesantanaranal")
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 = "melville")
EmergenceRateIndex(germ.counts = y, intervals = int, partial = FALSE,
method = "melvillesantanaranal")
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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