vigor {SeedCalc}

Seed Vigor Index

Description

It calculates the Seed Vigor Index (Sako, 2001).

Usage

vigor(lengths, wg = 0.7, wu = 0.3, Unif = 1)

Arguments

lengths

A data.frame object containing seedling lengths data with four columns. The first and second columns are for identification, e.g. treatments and repetitions. The third is the shoot length and the fourth is the root lenght.

wg

A numeric value between zero and one. Default is 0.7. Is the weight given to the seedling lenght in the Vigor index calculation.

wu

A numeric value between zero and one. Default is 0.3. Is the weight given to the Unif_2 index calculation.

Unif

A numeric value, 1 or 2. If 1, the unif_1 index is used for vigor index calculation. If 2, the Unif_2 index is used for Vigor index calculation.

References

SAKO, Y.; MCDONALD, M. B.; FUJIMURA, K.; EVANS, A. F.; BENNETT, M. A. A system for automated seed vigour assessment. Seed Science and Technology, v. 29, n. 3, p. 625-636, 2001.

Examples

Seedling <- data.frame(
LOTE = c(1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2),
REP = c(1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 2, 2, 2, 2),
SH = c(0.00, 2.77, 1.18, 1.07, 0.80, 2.65, 3.51, 0.64, 2.77, 1.18, 1.07, 0.80, 2.65, 3.51, 1.98),
ROOT = c(4.86, 6.71, 7.88, 3.68, 9.68, 8.88, 9.85, 4.86, 6.71, 7.88, 3.68, 9.68, 8.88, 9.85, 8.75)
)
print(Seedling)
VigInd <- vigor(Seedling, wg = 0.7, wu = 0.3, Unif = 1)
VigInd