[Phenological characterization of four cultivars [Valmoreno, Gaitan, Areces, Mount Baker] of Trifolium subterraneum under the climatic conditions of the province of humid swards with fresh summer]

Español; castellano. At the Universidad Austral de Chile "Santa Rosa" farm, located in Valdivia province, Chile, a research was carried out to make a phenologic and productive characterization of 4 subterraneum clover varieties under the climatic conditions of the "Provincia de pastizales humeda de verano fresco". This study was made on a pure subterraneum clover pasture, without management, but although it priorized the clover characterization under these conditions, considered measuring also some productive aspects under the effect of artificial defoliation. For parameters measured without defoliation a complete randomized block design was used with 4 treatments and 3 replicates, where treatments correspond to strains: Valmoreno (V), Gaitan (G), and Areces (A) proceeding from Spain, and Mount Barker (M) from Australia. Defoliation parameters were arranged in the same form. Comparison among some productive aspects with defoliation and without it, was made according to a 2 x 4 factorial arangement. Subterraneum clover was sown on April 20, 1991, with a Planet Junior machine, at a rate of 33 kg seed/ha, on a soil that had been previously plowed up and manually raked. Of the total area of experiment plots (10 m2), 70% was assigned to measurements without defoliation, making sampling every 30 days since the sowing date. Each time, whole plants were collected from 0,5 m2. For the sector under cutting, the remaining 30%, defoliations were made on November 20, obtaining samples with a 0,125 m2 quadrant thrown twice. After each forage taking the sector was leveled to a 3 cm residue, and the final cut was made on January 20. Maximum plant density (number of plants/m2) without cut was obtained reached at establishment