pop_reprod: Seed production and crop yield
In PROSPER: Simulation of Weed Population Dynamics

Description Usage Arguments Details References See Also Examples

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

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

`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` ≤ 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.

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).

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

pop_reprod pop_step

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)