Regrowth analysis of alfalfa (Medicago sativa, L.) during three seasons in 1966

Abstract

The rate of alfalfa regrowth during three seasons was associated with different parameters with the objective of finding a most suitable date of cutting in each season.

The rate and total dry matter produced was higher during spring and early summer seasons than in late summer.

The higher L.A.I. during spring than for the other two seasons may be attributed to production of new leaves because of weevil and frost damage. The greatest efficiency in L.A.I. occurred during early summer and the lowest in late summer; the same trend was observed in N.A.R.

Interception of 95% of the light required different L.A.I. values during the three seasons, and these values were reached at different dates of regrowth and stages of maturity. Maximum growth rates were not associated with 95% light interception.

Height was the best criteria for cutting date. However, the optimum heights were not related to days of regrowth.

The status of carbohydrate reserves differed within each season. These reserves generally declined immediately after defoliation, indicating that they furnish energy for regrowth.

The nutritive value of the forage generally declined as stage of maturity advanced.