Abstract

IXTAINA, V. Yanet  and  MUJICA, M. Merced. Seedling vigor response of Lotus tenuis populations to contrasting variations of water, light and nutrient availability. Agrociencia [online]. 2010, vol.44, n.1, pp.31-41. ISSN 2521-9766.

The intercrop of Lotus tennuis, a strategic legume to improve pasture, is constrained by the limited competitive ability of its seedlings. In this article we evaluated the influence of the environmental variations of water, light and nutrients on the characters involved in the implantation of populations of L. tennuis: air dry weight (PSA), number of stems in the crown (Nt), main stem length (Lt) and number of leaves unfolded on the main stem (Nh), in seven populations (P) under contrasting situations of water availability (A), fertilizer (F) and light (S). An effect of P on PSA was detected; the A and S affected all characters; F was found to have no effect; increasing PSA, Lt and Nh in flooding conditions showed a tolerant behavior, which can be a competitive advantage over other species under these conditions; shading reduced PSA, Nt and Nh, and ptomoted greater Lt. The intetaction A × S (p ≤ 0.001) for Lt and PSA was outstanding; the higher PSA of seedlings subjected to flooding and unrestricted light can be explained by the beneficial effect of abundant watet, which prevented potential temporary water stress. Variation among populations was detected only for PSA and there was no significant change in the test of the chatacters evaluated, thus limiting the expected response to selection at the interpopulation level. The strength of seedlings was detetmined by A and S, which should be taken into account in sowing planning. There was interaction P × S (p ≤ 0.05) for Nt and P × F × S (p ≤ 0.01) for Lt, although no populations × envitonments interaction was detected for the seedling vigor estimated by PSA not for Nh.

Keywords : Lotus tenuis Waldst et Kit; flooding; fertilization; shading; seedling vigor.