pop_reprod {PROSPER}

Seed production and crop yield

Description

Calculates the produced seeds and optionally the proportion of crop yield that is realized relative to weed free yield (Renton at al. 2011).

Usage

pop_reprod(start, area, kw, pen_co, kc, dc, crop_inr, SSmax, yield = FALSE)

Arguments

start

column names of parental cohorts. character vector.

area

number of area units. positive numeric.

kw

dimensionless weed competition parameter. numeric.

pen_co

penalty values for different weed cohorts. numeric vector, each element in [0,1].

kc

dimensionless crop competition parameter. numeric.

dc

crop sowing density, seeds per unit area. numeric.

crop_inr

position of the crop in the crop rotation. positive integer \le length of the crop rotation.

SSmax

maximum of weed seed production per unit area. positive integer.

yield

logical, whether the percentage of yield gained should be calculated.

Details

The number of produced seeds is calculated for 1m^2 by the formula:

over\_all = 1 + kc*dc[crop\_inr] + sum(kw*dw*pen\_co)

producedseeds = round(sum((SSmax[crop\_inr] * kw * dw * pen_co)/over\_all),digits=0)

propyield = (1 + kc*dc[crop\_inr])/over\_all

The weed density dw is calculated for each squaremeter derived from the current simulation run (start). The used parameters values apply to wheat and ryegrass (Pannell et al. 2004, cited in Renton et al. 2011).

References

Renton, M.; Diggle, A.; Manalil, S. & Powles, S. (2011): Does cutting herbicide rates threaten the sustainability of weed management in cropping systems? Journal of Theoretical Biology, 283, 14-27. Pannell, D. J.; Stewart, V.; Bennett, A.; Monjardino, M.; Schmidt, C. & Powles, S. B. (2004): RIM: a bioeconomic model for integrated weed management of Lolium rigidum in Western Australia Agricultural Systems, 79, 305-325

See Also

pop_reprod pop_step

Examples

struc_preparation2(Rmx=10, af=c(0.01,0.8), epis=0, dom=1)
#Distribute 10000 individuals of the starting population across the genotypes provided by tmp. 
#The two gene loci have initial frequencies of 0.01 and 0.8.
gen_freq(af=c(0.01,0.8), n_seeds=10000, max_vec_length=1e+07)
pop_reprod("initialSB",  area=100, kw=0.5, pen_co=1, kc=0.05, dc=100, 
                         crop_inr="wheat", SSmax=3000, yield=TRUE)
rm(producedseeds, dfgenotype, mf, xprobab, propyield)