Vitality and Vigour - Qualitative Characters

Vitality is related to the condition of a plant and its capacity to complete its life cycle, while vigor refers more specifically to the health or development within a certain stage. We can say that a seedling or a mature plant may be vigorous or it may be feeble or poorly developed. A number of criteria may be used in determining the vigour of plants such as the rate and total amount of growth especially in height; rapidity of growth renewal in spring or following mowing or grazing; area of foliage, colour and turgidity of leaves and stems; degree of damage caused by diseases or insects; time of appearance and number and height of flower stalks; rate of growth and extent of root system, appearance and development of new stems and leaves. For classification of vitality the following groups as given by Daubenmire (1968) are used:

V₁ - Plants whose seedlings die

V₂ - Seedlings grow, but unable to reproduce

V₃ - Reproduce only vegetatively

V₄ - Reproduce sexually, but are uncommon

V₅ - Reproduce sexually and grow regularly