# FirstGermTime: Time for first, last and peak germination In germinationmetrics: Seed Germination Indices and Curve Fitting

## Description

Compute the following metrics:

FirstGermTime

Time of first germination or Germination time lag (\mjseqnt_0) \insertCiteedwards_temperature_1932,czabator_germination_1962,goloff_germination_1975,labouriau_germinacao_1983,ranal_effects_1999,quintanilla_effect_2000germinationmetrics.

LastGermTime

Time of last germination (\mjseqnt_g) \insertCiteedwards_temperature_1932,labouriau_germinacao_1983,ranal_how_2006germinationmetrics.

TimeSpreadGerm

PeakGermTime

Peak time of germination or Modal time of germination \insertCiteranal_how_2006germinationmetrics.

## Usage

 1 2 3 4 5 6 7 FirstGermTime(germ.counts, intervals, partial = TRUE) LastGermTime(germ.counts, intervals, partial = TRUE) PeakGermTime(germ.counts, intervals, partial = TRUE) TimeSpreadGerm(germ.counts, intervals, partial = TRUE) 

## Arguments

 germ.counts Germination counts at each time interval. Can be partial or cumulative as specified in the argument partial. intervals The time intervals. partial logical. If TRUE, germ.counts is considered as partial and if FALSE, it is considered as cumulative. Default is TRUE.

## Details

Time of first germination indicates time of germination of the faster seeds in a seedlot.

Lower value of time of first germination indicates faster initiation of germination and lower value of time of last germination indicates faster termination of germination.

Time spread of germination (\mjseqnt_g-t_0) indicates difference between faster and slower germinating members of a sample.

Peak time of germination is the time in which highest frequency of germinated seeds are observed. Multiple peak times of germination are possible and if detected are indicated by a warning message.

## Value

For FirstGermTime, the time of first germination value in the same unit of time as specified in the argument intervals.

For LastGermTime, the time of last germination value in the same unit of time as specified in the argument intervals.

For TimeSpreadGerm, the time spread of germination value in the same unit of time as specified in the argument intervals.

For PeakGermTime, the time(s) of peak germination value(s) as a numeric vector in the same unit of time as specified in the argument intervals.

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## Examples

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 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) z <- c(0, 0, 0, 0, 11, 11, 9, 7, 1, 0, 1, 0, 0, 0) int <- 1:length(x) # From partial germination counts #---------------------------------------------------------------------------- FirstGermTime(germ.counts = x, intervals = int) LastGermTime(germ.counts = x, intervals = int) TimeSpreadGerm(germ.counts = x, intervals = int) PeakGermTime(germ.counts = x, intervals = int) # For multiple peak germination times PeakGermTime(germ.counts = z, intervals = int) # From cumulative germination counts #---------------------------------------------------------------------------- FirstGermTime(germ.counts = y, intervals = int, partial = FALSE) LastGermTime(germ.counts = y, intervals = int, partial = FALSE) TimeSpreadGerm(germ.counts = y, intervals = int, partial = FALSE) PeakGermTime(germ.counts = y, intervals = int, partial = FALSE) # For multiple peak germination time PeakGermTime(germ.counts = cumsum(z), intervals = int, partial = FALSE) 

germinationmetrics documentation built on Feb. 17, 2021, 5:09 p.m.