Use Drought Tolerance Index when you need to compute the drought tolerance index as stressed yield divided by control yield times one hundred. Enter Control yield and Stressed yield using the definitions and units below so the result can be reproduced.

Control yield

Control yield in kilograms; must be greater than zero.

Stressed yield

Stressed yield in kilograms; must not be negative.

The published tool contract uses this rule: Compute the drought tolerance index as stressed yield divided by control yield times one hundred.

Drought tolerance index

Drought tolerance index percentage.

A ratio or percentage can conceal the scale of its numerator and denominator and becomes sensitive to measurement error when the denominator is small.

Retain the original Control yield and Stressed yield values and their units alongside the result. Salt Tolerance Index is useful when you instead need to compute the salt tolerance index as stressed yield divided by control yield times one hundred. Seed Vigor Index provides another view by helping you compute the seed vigor index as germination percent times seedling length in centimeters divided by one hundred.

• Salt Tolerance Index

  Compute the salt tolerance index as stressed yield divided by control yield times one hundred.

• Seed Vigor Index

  Compute the seed vigor index as germination percent times seedling length in centimeters divided by one hundred.

• Vigorous Seedling Index

  Compute the vigorous seedling index as seedling dry mass in milligrams times the germination percentage divided by one hundred.