Seeding Rate Per Tray

Invert independent seed-to-surviving-plant probability to whole seeds per tray cell for caller occupancy target, then include purchasing loss; independence excludes shared cell failures and crowding effects.

Description

A tray cell can be occupied if at least one independently surviving seed succeeds.

A tray cell can be occupied if at least one independently surviving seed succeeds. Whole-seed rounding and purchase handling loss affect the required inventory.^[1]

When to use Seeding Rate Per Tray

Use this tool to invert independent seed-to-surviving-plant probability to whole seeds per tray cell for caller occupancy target, then include purchasing loss; independence excludes shared cell failures and crowding effects.

Prepare the plant, nutrient, light or scheduling measurements for the intended crop and period. Keep paired records aligned and confirm units and supplied target values.

How to use Seeding Rate Per Tray and understand its results

Prepare the plant, nutrient, light or scheduling measurements for the intended crop and period. Keep paired records aligned and confirm units and supplied target values.
Enter cellsPerTray, trayCount, germinationFraction, postGerminationSurvivalFraction, targetCellOccupancyFraction, handlingLossFraction using the field table and calculation rules, then run the tool.
Read seedsPerCell, sownSeedCount, requiredPurchasedSeedCount, modelCellOccupancyFraction. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
cellsPerTray	Cells per tray	integer	Required
trayCount	Tray count	integer	Required
germinationFraction	Germination fraction	number	Required
postGerminationSurvivalFraction	Post germination survival fraction	number	Required
targetCellOccupancyFraction	Target cell occupancy fraction	number	Required
handlingLossFraction	Handling loss fraction	number	Required

Use positive integer tray/cell counts, success fractions and target occupancy in (0,1], and handling loss in [0,1). Perfect success needs one seed per cell; a perfect occupancy target with success below one is rejected. Return whole seeds per cell, sown and ceil-adjusted purchased counts, and achieved independent-model occupancy.

p=germination × survival; seeds/cell=ceil[log(1−target occupancy)/log(1−p)]

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
seedsPerCell	Seeds per cell	number
sownSeedCount	Sown seed count	number
requiredPurchasedSeedCount	Required purchased seed count	number
modelCellOccupancyFraction	Model cell occupancy fraction	number

json

{
  "input": {
    "cellsPerTray": 100,
    "trayCount": 2,
    "germinationFraction": 0.8,
    "postGerminationSurvivalFraction": 0.9,
    "targetCellOccupancyFraction": 0.95,
    "handlingLossFraction": 0.1
  },
  "output": {
    "seedsPerCell": 3,
    "sownSeedCount": 600,
    "requiredPurchasedSeedCount": 667,
    "modelCellOccupancyFraction": 0.978048
  }
}

Limitations and assumptions

Independence excludes shared cell failures and crowding. All counts must remain safe integers.

Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use First Season Seedling Survival Percent: Separate first-season tagged survival among located seedlings from whole-cohort bounds for unlocated tags; missing plants are not forced dead or alive. For a complementary task, use Natural Regeneration Stock Minimum Count Tool: Audit field regeneration counts against caller local minimum density, retaining patch-level shortfall rather than hiding unstocked plots in the pooled density; not legal stocking compliance.

References

Seeding Rate Per Tray — tool.io

Similar or alternative tools

First Season Seedling Survival Percent
Separate first-season tagged survival among located seedlings from whole-cohort bounds for unlocated tags; missing plants are not forced dead or alive.
Natural Regeneration Stock Minimum Count Tool
Audit field regeneration counts against caller local minimum density, retaining patch-level shortfall rather than hiding unstocked plots in the pooled density; not legal stocking compliance.