Comportamiento agronómico de tres variedades de alfalfa (Medicago sativa L.) con diferentes dosis de fertilización fosfatada.

The objective of this study was to evaluate the agronomic performance of three Medicago sativa L. varieties with three doses of phosphate fertilization, during establishment, in the Ecuadorian mountains. The trial was conducted at the Tunshi Research Station, located in the Riobamba canton, Chimborazo province -Ecuador-. The treatments were: the alfalfa varieties as factor A (abunda verde, cuf-101 and sw-8210) and the fertilization doses (0, 50, 100 and 150 kg P/ha) as factor B, compared with the ecotype flor morada (control). The experimental plots were distributed in a completely randomized block design, with split-plot arrangement and three repetitions; variance analysis and mean comparison according to Tukey were carried out. Significant differences (p < 0,05) were recorded for the A x B interaction. The emergence percentage when 100 kg P/ha were applied was 95,67 % for the variety sw-8210, which differed significantly (p < 0,05) from the ecotype flor morada without fertilization (90,33 %). This ecotype reached 99,59 % of aerial cover and 34,09 % of basal cover in the first cut (110 days), and differed significantly (p < 0,01) from the introduced varieties. The ecotype flor morada without fertilization produced 17,23 and 4,52 t/ha per cut of green and dry forage, respectively; and surpassed (p < 0,01) the variety abunda verde (7,46 and 2,79 t/ha, respectively). It is concluded that the ecotype flor morada showed higher green and dry forage yield, and better cover and plant height without phosphate fertilization; likewise, the harvest was performed at 110 days after sowing, when the plants showed 10 % of flowering. [ABSTRACT FROM AUTHOR]