CRESCIMENTO INICIAL DA INVASORA Cryptostegia madagascariensis BOJER EX DECNE. EM DIFERENTES SUBSTRATOS

Abstract

Biological invasion is characterized by the introduction of an exotic organism capable of adapt and change the ecosystem, competing with indigenous species. In Northeast, caatinga is one of the plant formations where was observed the occurrence of areas with a strong presence of invasive exotic species such as Cryptostegia madagascariensis. Due to the characteristics of its flowers this, specie was introduced in several regions with ornamental purposes, which contributed to its spread. If the invasive plant adapts its self in the location, autorregenerantes populations can arise naturally, especially in degraded areas and the banks of streams and temporary ponds. Therefore, the aim of this work was to evaluate the growth potential of the invasive C. madagascariensis in different substrate conditions, considering types and volumes. The experiment was conducted in the nursery of Laboratory of Plant Ecology, Centre of Agricultural Sciences, Federal University of Paraíba. Treatments were arranged in a randomized complete block design with three replications and 29 substrates was obtained by combinations of different proportions of soil, sand washed, goat manure and sawdust, placed in three containers with capacities of 0.5; 1.5 and 3,0 liters. The height growth was higher in the substrate composed of 50% manure, 25% soil and 25% sand (46.47 cm). With respect to containers, the best values were obtained in medium and large containers, whose values were respectively 18.96 and 20,17cm. When was combined 50% manure, 25% soil and 25% sand, the plants formed 10.6 leafs per plant, which was the best value. Thus we conclude that C madagascariensis was able to grow on substrates of various compositions, except for the sawdust. Also, larger volumes of higher substrates enabled the growth of plants.