CRESCIMENTO INICIAL DE PORTA-ENXERTOS DE GOIABEIRA IRRIGADOS COM ÁGUAS SALINAS

Abstract

With the purpose of evaluating effects of salinity of irrigation water on initial development of rootstocks of guava (Psidium guajava L), an experiment was conducted in greenhouse at Experimental Station of Pacajus, belonging to Embrapa Tropical Agroindustry in the State of Ceará. The treatments in randomized block design consisted of five levels of electrical conductivity of water (ECw: 0.5; 1.5; 2.5; 3.5 and 4.5 dS m-1) and two cultivars of guava (Rica and Ogawa) with four replications. The irrigation waters were prepared maintaining equivalent proportion of 7:2:1 respectively of Na:Ca:Mg. Seedlings were appraised 80 days after emergence, the effects, on number of leaves, plant height, diameter of stem, phytomass of the root and aerial parts, total phytomass, diameter, leaf area and root to aerial part ratio were studied. The increment of water salinity affected growth of cultivar in terms of number of leaves, stem diameter plant height, the Ogawa cultivar was found to be more affected. In highest level of water salinity (4.5 dS m-1) the relative reduction in total dry phytomass in case of cultivar Rica was 63.5% while the decrease in cultivar Ogawa was higher (77.4%); with regard to leaf area the effect was linear with reduction of 17.2% and 18.4%, respectively, for unit increase of water salinity. In cultivar Rica roots and in cultivar Ogawa the aerial parts were most affected negatively by water salinity.