ChillModels (version 1.0.2)

utah_model: Utah Model

Description

Quantifies the chill accumulation by means of converting temperatures to chill-units.

Usage

utah_model(x, total = TRUE)

Arguments

x

Vector containing temperature values (Celsius-degree).

total

TRUE Shows the total value of accumulation, FALSE shows the value of chill-unit for each temperature (TRUE is default).

Value

The function returns values the chill-units for each temperature of vector (Total = FALSE), or returns the chill-units accumulation (Total = TRUE).

Details

The model is based on chill-units, where 1 chill-unit is when the tree is exposure between 2.4<U+00B0>C and 9.1<U+00B0>C, being the optimum temperature 6<U+00B0>C . When the temperature is between 9.1<U+00B0>C and 12.4<U+00B0>C, the chill-unit is 0.5. The chill-units accumulation is 0 when occurs temperature below 1.4 and between 12.5<U+00B0>C and 15.9<U+00B0>C. When the temperature is between 16<U+00B0>C and 18<U+00B0>C, the chill-unit is -0.5. When the temperature is above 18<U+00B0>C, the chill-unit is -1.

References

Richardson, E, A. et al. 1974. "A Model for Estimating the Completation of Rest for 'Redhaven' and 'Elberta' Peach Trees". Research Reports & Notes.

Examples

# NOT RUN {
x <- rnorm(500, 5, 3)
utah_model(x)
utah_model(x, FALSE)

# }