Productive Performance of Alfalfa (Medicago sativa L.) at Different Age of Resprout in the Spring Season

Abstract

The objective was to determine the growth and productive behavior curves, to obtain the optimal cutting momento in alfalfa, depending on the grwth age, in the spring season. The treatments were cuts at different age of the plant and the variables evaluated: Dry Matter Yield (DMY) Botanical and Morphological composition (CBM), Plant Height (PH), Ration: Leaf/Stem (R:L/S)and Intercepted Radiation (IR). The stastical analysis was with the PROC GLM procedure, of the SAS and the adjustedcurves were obtained with the Curve Expert Professional 2.0 program. There was an increase in the DMY, leaf, stem, PH, and IR, as the regrowth age advanced, but not, the R:L/S had an inverse behavior. In week seven the máximum DMY was obtained (4,768 kg DM ha^-1). There was a greater amount of leaf with an average 52 %, followed by the steam (36 %), weeds (7 %), dead material (4 %) and inflorescence (1%). The PH was higher in week seven with 53 cm. Likewise, the highest IR in week tree with 86 %. However, the R:L/S was higher in week one with 2,4. The RI and R:L/S presented the lowest R² (0.90 and 0.93, respectively). In contrast, DMY and PH presented a positive relationship (R² of 0.98 and 0.97, respectively). The productive performance of Premium variety alfalfa was variable depending on the regrowth age, in wich the botanical and morphological characteristics changed, with better characteristics in the fifth week.